Showing posts with label intervals. Show all posts
Showing posts with label intervals. Show all posts
Sunday, January 24, 2010
HIIT (on bikes) - why it results in both more fat reduction, and Spot Fat Reduction at That, too than Hearty Steady State
Follow @mcphoo
Tweet
There are lots of folks espousing the value of HIIT as an effective calorie burner when trying to burn fat. But is there really a special role for HIIT in the fat burning lexicon, or should we just strive to work harder - like 50-75% VO2max - throughout a cardio session? Some more recent work suggests there may be in terms of metabolic activity and even spot fat reduction. But before we go there, let's refresh a bit about HIIT.
The old argument that HIIT burns more calories than Steady State and so is beter has been given a good walloping by Lyle McDonald. Especially in his head to head of steady state with HIIT he pretty persuasively shows that "The intervals only come out a TINY bit ahead if you compare workouts of identical length and even there the difference is absolutely insignificant."
Review: What's HIIT supposed to Do?
Indeed, work from 2008 lead by Shannan E.
Gormley comparing intervals to a decent level of steady state effort did show a benefit for intervals of a sort, but the question for the researchers is what's the optimal time to spend at that peak intensity in an interval to elicit this effect? As cited previously here, the authors state:
So what about fat loss & HIIT, then?
HIIT means high intensity interval protocol. But what is the best HIIT to do if you're tuning it for fat lost first, and anything else second? And does it make a difference if you're dealing with elite athletes or people who are just well enough conditioned so their hearts won't explode if you ask them to go "really hard" for a bit? Is it 60 secs on? 30 off? 60:60? The infamous tabatta on for 20 off for 10 - and remember that was not primarily a fat burning study but an anaerobic/aerobic capacity study.
In 2007 & 2008 a couple studies came out on HIIT from New South Wales as part of some cool PhD work lead by Gail Trapp that i have come to cite frequently about a great HIIT protocol for fat loss and other cool, related benefits that looked explicitly at intervals for fat burning and effects between conditioned and less conditioned participants. Here's the first one, looking at what different HIIT intervals stir up metabolically.
Any type of heart rate elevation triggers some catecholamine response - so does drinking green tea. But what the authors show
here is that both long and short high intensity efforts - sprints in this case - can be effective to trigger greater catecholomine release, but the longer 24 sec sprint with its equivalent longer recovery seems to be better overall for fat mobilization. That's cool. That's actually less work/minute at 24 secs on 36 off than the shorter burst of 8on/12off (24sec vs 40secs of work). Wow. So longer more intense intervals - not necessarily more work - yields higher levels of fat release for fuel - but both the shorties and the longies are good.
Applying these Inervals to Fat Loss. Trapp and Co. then took this finding to a larger cohort of 45 participants (up from 8 and 8), and went longitudinal running a 15 week study. 15 weeks is *good* for 45 people to hang in there.
To be clear, in the second study, gals in the HIIT group did a five minute warm up, followed by 20mins of 8sec sprint followed by 12s of 20-30rpm recovery. The load was continually adjusted over the course of 15 weeks, starting at everyone getting to 20mins at .5kg of resistance. Based on heart rate, the load was upped by .5kg so that the heart effect was consistent as folks got stronger.
The steady state group worked at 60%V02peak - that's a good clip - about 75% maxHR so no slouching there. They worked up from 10mins to 40mins. The mean heart rate of the groups was 168.6 for the HIIT group; 155.7 for the steady state group (participants were 18-30 years old).
As to the fat loss: There was significant FM loss (P less than 0.05) r="−0.58,">This last point is not surprising, based on energy available for fuel from fat relative to bodyfat % (discussed here). The authors come back to this point stating:
Discussion of Findings - Cautious optimism for Intense Intervals
The authors in true geek science-ness don't overegg the results:
more fat available as fuel in the blood ready to be used, Trapp's crew hypothesizes, maybe people doing HIIT just aren't homeostatically tweaked to reach for calorically dense foods - their bodies know they have that covered. That's a really intersting idea. I wonder if doing HIIT closer to meal times enhances this effect, if that's what's going on.
What about this seeming spot reduction? But even if you want to say there are interesting side effects going on with HIIT that are causing these fat loss responses, the authors' key result is this abdominal fat difference. HIIT took OFF some ab fat; Steady state, i'm sorry to say, put some on. Dang.
Here's where exercise type may play an important role in whether or not this spot effect is achieved. The authors postulate the following:
Translating Results to Other Modes? Do these findings translate to other modalities for HIIT - like oh i dunno, maybe kettlebells? Don't know. Perhaps that would be an interesting comparison for bike, hardstyle with it's tension at the top of the swing say, and that hip/core/lat activation, and GS with its more relaxed swing. Do GS/HS differences fall away as the bell weight gets heavier?
In the meantime, the authors offer the following:
While the authors tested their participants with the 8/12 interval, their earlier work with the 24/36 suggests the benefits might be even greater - on a bike, but maybe with a kettlebell or a rowing machine, too.
Take Away: the Skinny on the Fat & HIIT
There are at least two ways to talk about HIIT - in the performance arena, and in fat burning. In performance, there is a small but not insignificant edge to interval work over intense steady state. In fat burning there is a really significant effect. Here's what i think it is.
While the authors make much of the spot fat reduction - and that's not nothing - the more intriguing thing is that *only* the HIIE group lost fat & had their lean body mass go up.
I've cited before work to show that without diet, any weight loss changes, even over 12 weeks of working out are small. In this case, there was no deliberate dietary intervention. So that there was such fat loss without more or less trying dietarily as well is really kinda eye openingly "what the heck?"
So i am intrigued by the authors' speculation about that catecholamine effect and glycerol release and potential effect on let's say homeostasis - a reduced reach for high cal foods, naturally. Wow. That makes HIIE worth looking at from a whole other point that has a whole lot less to do with the calories burned on the bike and the effect of those intervals throughout every other day of the week. And that's only 3*15. What would 3days at 20 or 30 or 40 minutes do? More is not always better - and intervals can be fatiguing but. Hmm.
Related Posts
main refs
There are lots of folks espousing the value of HIIT as an effective calorie burner when trying to burn fat. But is there really a special role for HIIT in the fat burning lexicon, or should we just strive to work harder - like 50-75% VO2max - throughout a cardio session? Some more recent work suggests there may be in terms of metabolic activity and even spot fat reduction. But before we go there, let's refresh a bit about HIIT.The old argument that HIIT burns more calories than Steady State and so is beter has been given a good walloping by Lyle McDonald. Especially in his head to head of steady state with HIIT he pretty persuasively shows that "The intervals only come out a TINY bit ahead if you compare workouts of identical length and even there the difference is absolutely insignificant."
Review: What's HIIT supposed to Do?
Indeed, work from 2008 lead by Shannan E.
Gormley comparing intervals to a decent level of steady state effort did show a benefit for intervals of a sort, but the question for the researchers is what's the optimal time to spend at that peak intensity in an interval to elicit this effect? As cited previously here, the authors state:It should be noted that although interval training groups spend some of their training time at a very high intensity, a similar amount of time is spent at a lower intensity, and therefore the mean intensity of training may not be any higher than that of a continuous training program. In the current study, the interval training group used 5 min each for the work and the recovery phases of the intervals and had an average intensity of 72% HRR, which is slightly less than the 75% HRR of the vigorous [the steady state -mc] group. The work-recovery periods of Helgerud et al.[16] were 4 min at ∼93% HRmax and 3 min at 70% HRmax, for a mean intensity of 83% HRmax in the interval group, whereas one of the continuous groups used 85% HRmax. Warburton et al.[37] used 2 min at 90% HRR and 2 min at 40% HRR for the work and the recovery phases, yielding a mean intensity of 65% HRR in the interval group, and had the continuous training group use 65% HRR. Wisloff et al.[38] used 4-min work phases at ∼93% HRmax and 3-min recovery phases at 60% HRmax, for a mean intensity of 79% HRmax in the interval group, and used ∼73% HRmax in the continuous training group. Despite the similarity of mean intensity between the interval and the continuous training groups, the interval groups in all of these studies experienced greater improvements in aerobic fitness after training. Therefore, although intensity is a key variable in cardiorespiratory training (as shown by comparing the two continuous training groups in this study), the mean intensity may not be as important as the highest intensity that is used for a significant portion of the training. A topic for future research is to determine what portion of training should be done at high intensities and using what work-recovery periods to obtain the greatest resultsThe above is looking not at fat loss effects of intervals, but training to enhance oxidative capacity for performance. More recently even really brief intense bouts of exercise (like 6 mins a week of effort compared with hours of steady state for the same physiological effect as hours of 60% MaxHR), there are similar kinds of performance benefits. So, there seem to be some performance optimization benefits from (a) looking at finding the right balance of peak intensity to recovery for work sessions and (b) looking at supramaximal efforts that may have similar effects in less time. Again, that's performance, not fat loss, and in the former case, we are talking really small degrees of difference.
So what about fat loss & HIIT, then?
HIIT means high intensity interval protocol. But what is the best HIIT to do if you're tuning it for fat lost first, and anything else second? And does it make a difference if you're dealing with elite athletes or people who are just well enough conditioned so their hearts won't explode if you ask them to go "really hard" for a bit? Is it 60 secs on? 30 off? 60:60? The infamous tabatta on for 20 off for 10 - and remember that was not primarily a fat burning study but an anaerobic/aerobic capacity study.
In 2007 & 2008 a couple studies came out on HIIT from New South Wales as part of some cool PhD work lead by Gail Trapp that i have come to cite frequently about a great HIIT protocol for fat loss and other cool, related benefits that looked explicitly at intervals for fat burning and effects between conditioned and less conditioned participants. Here's the first one, looking at what different HIIT intervals stir up metabolically.
Am J Physiol Regul Integr Comp Physiol. 2007 Dec;293(6):R2370-5. Epub 2007 Sep 26.Fat Mobilization: Freed for the Burning. Ah ha you say, there's no fat loss measured here. Right. But what IS measured here is catecholamine activation. Those threat response fight or flight hormones are what mobilize fat to get burned, baby burned. And from these the authors suggest a correlation to the level of catecholamine released and the level of glycerol to be found in the blood stream. In other words, higher degree of intensity, greater catecholamine release, more fat mobilised to be used for fuel.
Metabolic response of trained and untrained women during high-intensity intermittent cycle exercise.
Trapp EG, Chisholm DJ, Boutcher SH.
School of Medical Sciences, Faculty of Medicine, Univ. of New South Wales, Sydney 2052, Australia. e.trapp@unsw.edu.au
The metabolic response to two different forms of high-intensity intermittent cycle exercise was investigated in young women. Subjects (8 trained and 8 untrained) performed two bouts of high-intensity intermittent exercise: short sprint (SS) (8-s sprint, 12-s recovery) and long sprint (LS) (24-s sprint, 36-s recovery) for 20 min on two separate occasions. Both workload and oxygen uptake were greater in the trained subjects but were not significantly different for SS and LS. Plasma glycerol concentrations significantly increased during exercise. Lactate concentrations rose over the 20 min and were higher for the trained women. Catecholamine concentration was also higher postexercise compared with preexercise for both groups. Both SS and LS produced similar metabolic response although both lactate and catecholamines were higher after the 24-s sprint. In conclusion, these results show that high-intensity intermittent exercise resulted in significant elevations in catecholamines that appear to be related to increased venous glycerol concentrations. The trained compared with the untrained women tended to show an earlier increase in plasma glycerol concentrations during high-intensity exercise.
Any type of heart rate elevation triggers some catecholamine response - so does drinking green tea. But what the authors show
here is that both long and short high intensity efforts - sprints in this case - can be effective to trigger greater catecholomine release, but the longer 24 sec sprint with its equivalent longer recovery seems to be better overall for fat mobilization. That's cool. That's actually less work/minute at 24 secs on 36 off than the shorter burst of 8on/12off (24sec vs 40secs of work). Wow. So longer more intense intervals - not necessarily more work - yields higher levels of fat release for fuel - but both the shorties and the longies are good.Applying these Inervals to Fat Loss. Trapp and Co. then took this finding to a larger cohort of 45 participants (up from 8 and 8), and went longitudinal running a 15 week study. 15 weeks is *good* for 45 people to hang in there.
Int J Obes (Lond). 2008 Apr;32(4):684-91. Epub 2008 Jan 15.
The effects of high-intensity intermittent exercise training on fat loss and fasting insulin levels of young women.
Trapp EG, Chisholm DJ, Freund J, Boutcher SH.
Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia. e.trapp@unsw.edu.au
OBJECTIVE: To determine the effects of a 15-week high-intensity intermittent exercise (HIIE) program on subcutaneous and trunk fat and insulin resistance of young women. DESIGN AND PROCEDURES: Subjects were randomly assigned to one of the three groups: HIIE (n=15), steady-state exercise (SSE; n=15) or control (CONT; n=15). HIIE and SSE groups underwent a 15-week exercise intervention. SUBJECTS: Forty-five women with a mean BMI of 23.2+/-2.0 kg m(-2) and age of 20.2+/-2.0 years. RESULTS: Both exercise groups demonstrated a significant improvement (P<0.05) in cardiovascular fitness. However, only the HIIE group had a significant reduction in total body mass (TBM), fat mass (FM), trunk fat and fasting plasma insulin levels. There was significant fat loss (P<0.05) in legs compared to arms in the HIIE group only. Lean compared to overweight women lost less fat after HIIE. Decreases in leptin concentrations were negatively correlated with increases in VO(2peak) (r=-0.57, P<0.05) and positively correlated with decreases in TBM (r=0.47; P<0.0001). There was no significant change in adiponectin levels after training. CONCLUSIONS: HIIE three times per week for 15 weeks compared to the same frequency of SSE exercise was associated with significant reductions in total body fat, subcutaneous leg and trunk fat, and insulin resistance in young women.
To be clear, in the second study, gals in the HIIT group did a five minute warm up, followed by 20mins of 8sec sprint followed by 12s of 20-30rpm recovery. The load was continually adjusted over the course of 15 weeks, starting at everyone getting to 20mins at .5kg of resistance. Based on heart rate, the load was upped by .5kg so that the heart effect was consistent as folks got stronger.
The steady state group worked at 60%V02peak - that's a good clip - about 75% maxHR so no slouching there. They worked up from 10mins to 40mins. The mean heart rate of the groups was 168.6 for the HIIT group; 155.7 for the steady state group (participants were 18-30 years old).
As to the fat loss: There was significant FM loss (P less than 0.05) r="−0.58,">This last point is not surprising, based on energy available for fuel from fat relative to bodyfat % (discussed here). The authors come back to this point stating:
High-intensity intermittent exercise training had a marked effect on fat levels for some individuals and a moderate effect for others. The correlation (r=0.58, P less than 0.01)43, 44 The four moderate fat loss responders in the HIIE group (women who had a 3% or less decrease in total fat) possessed significantly lower initial FM than the other women. With the four lean women removed, the mean fat loss in the HIIE group was 3.94±0.91 kg resulting in a 4.3% decrease in body mass and a 14.7% decrease in total FM. This 3.94-kg fat loss compares favorably to the 1.15-kg weight loss reported in a recent meta-analysis of the effects of SEE on weight loss.That all sounds good and reasonable and wonderful, but then comes the particularly interesting bits - gosh what would almost seem like spot fat reductions:
High-intensity intermittent exercise led to a significant decrease (P less than 0.05) in central abdominal fat (−0.15plus or minus 0.07 kg), whereas the SSE and CONT groups had nonsignificant increases in central abdominal fat (SSE group, +0.1 plus or minus 0.08 kg; CONT group, +0.03 plus or minus 0.04 kg).So more weight off the gut area in HIIT, legs and trunk (other newer work (like this one Nov 08 lead by Irving, and this one Aug 09 lead by Coker ) has seen similar results with gut fat). Intriguingly all groups put on fat in the arms (but not a lot). Indeed, the gut fat loss the authors cite as THE finding of the study. Even more, they state
Despite exercising half the time, HIIE subjects in the present study lost 11.2% of total FM with SSE subjects experiencing no fat loss.That's a pretty big difference between the two groups
Discussion of Findings - Cautious optimism for Intense Intervals
The authors in true geek science-ness don't overegg the results:
Collectively, these results demonstrate that intermittent sprinting compared to SEE is a more effective and efficient way of controlling body composition. However, our estimates of energy expenditure and intake lack sufficient precision to comfortably conclude that energy balance was unaffected in the HIIE condition. Thus, it is feasible that the change in FM that occurred in HIIE may have been influenced by unreported changes in diet. Indeed, HIIE-induced suppressed diet intake may be one of a number of possible factors underlying the fat loss effect of HIIE.11 For example, HIIE may have suppressed appetite or decreased attraction for energy-dense foods.24, 25 Another explanation for the HIIE fat loss effects is that this type of exercise may result in enhanced lipid utilization. Prior research in our laboratory has shown that lipid release, as indicated by blood glycerol levels, gradually increased over 20 min of HIIE.20 Catecholamine levels in this study were also found to be significantly elevated after HIIE.20Free Fat. I love this! Because of that catecholomine hit we saw earlier, and because there's
more fat available as fuel in the blood ready to be used, Trapp's crew hypothesizes, maybe people doing HIIT just aren't homeostatically tweaked to reach for calorically dense foods - their bodies know they have that covered. That's a really intersting idea. I wonder if doing HIIT closer to meal times enhances this effect, if that's what's going on. What about this seeming spot reduction? But even if you want to say there are interesting side effects going on with HIIT that are causing these fat loss responses, the authors' key result is this abdominal fat difference. HIIT took OFF some ab fat; Steady state, i'm sorry to say, put some on. Dang.
Here's where exercise type may play an important role in whether or not this spot effect is achieved. The authors postulate the following:
It is considered that spot reduction (that is, deliberately reducing fat stores in specific areas of the body) is not possible, and the body will mobilize preferentially those stores with the highest concentrations of adipose cells.36, 37, 38 There is evidence in the current study that this principle may not apply to every exercise modality. In HIIE, where work is done primarily by the musculature of the legs and the trunk muscles act as stabilizers, there was a decrease in FM and an increase in lean mass, which summated to a significant change in percentage of fat in these two regions. This was not the case with the SSE group.So where work triggers core stabilizers to get that extra intensity, there may be a seeming spot fat loss effect. It's also interesting to note that only the HIIT group had lean body mass increase.
Translating Results to Other Modes? Do these findings translate to other modalities for HIIT - like oh i dunno, maybe kettlebells? Don't know. Perhaps that would be an interesting comparison for bike, hardstyle with it's tension at the top of the swing say, and that hip/core/lat activation, and GS with its more relaxed swing. Do GS/HS differences fall away as the bell weight gets heavier?In the meantime, the authors offer the following:
In conclusion, 20 min of HIIE [on a bike - mc] , performed three times per week for 15 weeks compared to the same frequency of 40min of SSE exercise was associated with significant reductions in fasting insulin, total body fat, subcutaneous leg fat and abdominal fat.
While the authors tested their participants with the 8/12 interval, their earlier work with the 24/36 suggests the benefits might be even greater - on a bike, but maybe with a kettlebell or a rowing machine, too.
Take Away: the Skinny on the Fat & HIIT
There are at least two ways to talk about HIIT - in the performance arena, and in fat burning. In performance, there is a small but not insignificant edge to interval work over intense steady state. In fat burning there is a really significant effect. Here's what i think it is.
While the authors make much of the spot fat reduction - and that's not nothing - the more intriguing thing is that *only* the HIIE group lost fat & had their lean body mass go up.
I've cited before work to show that without diet, any weight loss changes, even over 12 weeks of working out are small. In this case, there was no deliberate dietary intervention. So that there was such fat loss without more or less trying dietarily as well is really kinda eye openingly "what the heck?"
So i am intrigued by the authors' speculation about that catecholamine effect and glycerol release and potential effect on let's say homeostasis - a reduced reach for high cal foods, naturally. Wow. That makes HIIE worth looking at from a whole other point that has a whole lot less to do with the calories burned on the bike and the effect of those intervals throughout every other day of the week. And that's only 3*15. What would 3days at 20 or 30 or 40 minutes do? More is not always better - and intervals can be fatiguing but. Hmm.
Related Posts
- Kettlebells and Cardio - it doesn't have to be VO2max all the time
- Viking Warrior Conditioning, the Review with Kenneth Jay
- Does Cardio interfer with Strength work? How 'bout No
- Running the bells - hill workouts with kettlebells
- Weight loss doesn't work without Diet - really [story 1, story 2]
- Fat, the amazing fuel.
- Getting a handle on the habits of thinner peace (as martha beck calls it)
main refs
Trapp, E., Chisholm, D., Freund, J., & Boutcher, S. (2008). The effects of high-intensity intermittent exercise training on fat loss and fasting insulin levels of young women International Journal of Obesity, 32 (4), 684-691 DOI: 10.1038/sj.ijo.0803781Tweet Follow @begin2dig
GORMLEY, S., SWAIN, D., HIGH, R., SPINA, R., DOWLING, E., KOTIPALLI, U., & GANDRAKOTA, R. (2008). Effect of Intensity of Aerobic Training on VO2max Medicine & Science in Sports & Exercise, 40 (7), 1336-1343 DOI: 10.1249/MSS.0b013e31816c4839
Trapp, E., Chisholm, D., & Boutcher, S. (2007). Metabolic response of trained and untrained women during high-intensity intermittent cycle exercise AJP: Regulatory, Integrative and Comparative Physiology, 293 (6) DOI: 10.1152/ajpregu.00780.2006
PDF
Tuesday, August 18, 2009
The Advantage of an Office Door: A Work Up for a Carb Up
Follow @mcphoo
Tweet
Ever stolen a work out during the day, or snuck one in? Do you have to go to the gym to do it? At work, i have the privilege of an office with a door on it such that when it's shut, no one can see in, except the workers in the building going up right across from me. We wave at each other from time to time. when they're way hi up on their lego like structures. But now since they're all off for lunch, it is fine and proper to change my shirt and shorts for sweatable attire and commence a pre-lunch ritual: the carb burn pre load work up.
Yes work up: i am working up to a happy feeding time, knowing i'm not just eating cuz i'm a bit peckish; i'm refurbishing my muscles glycogen stores when they'll be happiest to receive them.
To achieve this today, i decide to do a 15:15 vo2max workout as per Viking Warrior Conditioning (reviewed here).
But then, mid workout, what happens? i start to feel a callus go - for those of you who do this kind of thing you know what i mean. I don't want a tear - i'm about to go away on a break and while i suppose that would be the ideal time to have a tear (if one must) i think i'd rather not. Band aids etc, no fun. Phooey.
So i do the a-typical smart thing and stop my vo2max work with a 12kg and transition gracefully into an on-the-fly adapted 8on 12 off session of swings for the next 11 minutes with a 24kg. Perfect form, perfect form. Every rep a perfect rep. My word, 12 secs post kettlebell seems much shorter post a kettlebell set than it does on the bike.
This protocol is based on one developed by Trapp and co for eliciting optimal fat burn in women of both athletic and not so athletic backgrounds. 20mins of 8/12 intervals seemed to be a sweet spot for fat burning.
As for the application of the above with a heavy kb, i can say after the 11th minute, it seems i may have found a way to test for a new max heart rate. Cuz that was higher than on a bike and not maximal. I was still standing. Hmm. On the fat loss, well i don't know. It's more effortful than on a bike. May try again with a 20kg, just to calibrate. Interesting enough to want to give it a go again.
Feeling very pleased to have done this work up.
Clean up; re-dress and regroup. Lunch becomes a happy happy thing. A definite re-fuel. Ideally if i'd been thinking straight i would have grabbed a lighter bell just to do some more cool down swings to get a bit more fat flamed off before it re-esterfies from sitting down again.
So what's the take away here:
If you'd like more info on feeding up and why post workout, and what that has to do with muscles, here' a bit more in a review i did of precision nutrition's individualization/carb tolerance.
Now for the post happy lunch cup of tea... Tweet Follow @begin2dig
Yes work up: i am working up to a happy feeding time, knowing i'm not just eating cuz i'm a bit peckish; i'm refurbishing my muscles glycogen stores when they'll be happiest to receive them.
To achieve this today, i decide to do a 15:15 vo2max workout as per Viking Warrior Conditioning (reviewed here).
But then, mid workout, what happens? i start to feel a callus go - for those of you who do this kind of thing you know what i mean. I don't want a tear - i'm about to go away on a break and while i suppose that would be the ideal time to have a tear (if one must) i think i'd rather not. Band aids etc, no fun. Phooey.
So i do the a-typical smart thing and stop my vo2max work with a 12kg and transition gracefully into an on-the-fly adapted 8on 12 off session of swings for the next 11 minutes with a 24kg. Perfect form, perfect form. Every rep a perfect rep. My word, 12 secs post kettlebell seems much shorter post a kettlebell set than it does on the bike.
This protocol is based on one developed by Trapp and co for eliciting optimal fat burn in women of both athletic and not so athletic backgrounds. 20mins of 8/12 intervals seemed to be a sweet spot for fat burning.
Metabolic response of trained and untrained women during high-intensity intermittent cycle exercise.
School of Medical Sciences, Faculty of Medicine, Univ. of New South Wales, Sydney 2052, Australia. e.trapp@unsw.edu.au
The metabolic response to two different forms of high-intensity intermittent cycle exercise was investigated in young women. Subjects (8 trained and 8 untrained) performed two bouts of high-intensity intermittent exercise: short sprint (SS) (8-s sprint, 12-s recovery) and long sprint (LS) (24-s sprint, 36-s recovery) for 20 min on two separate occasions. Both workload and oxygen uptake were greater in the trained subjects but were not significantly different for SS and LS. Plasma glycerol concentrations significantly increased during exercise. Lactate concentrations rose over the 20 min and were higher for the trained women. Catecholamine concentration was also higher postexercise compared with preexercise for both groups. Both SS and LS produced similar metabolic response although both lactate and catecholamines were higher after the 24-s sprint. In conclusion, these results show that high-intensity intermittent exercise resulted in significant elevations in catecholamines that appear to be related to increased venous glycerol concentrations. The trained compared with the untrained women tended to show an earlier increase in plasma glycerol concentrations during high-intensity exercise.
As for the application of the above with a heavy kb, i can say after the 11th minute, it seems i may have found a way to test for a new max heart rate. Cuz that was higher than on a bike and not maximal. I was still standing. Hmm. On the fat loss, well i don't know. It's more effortful than on a bike. May try again with a 20kg, just to calibrate. Interesting enough to want to give it a go again.
Feeling very pleased to have done this work up.
Clean up; re-dress and regroup. Lunch becomes a happy happy thing. A definite re-fuel. Ideally if i'd been thinking straight i would have grabbed a lighter bell just to do some more cool down swings to get a bit more fat flamed off before it re-esterfies from sitting down again.
So what's the take away here:
- glad i've FINALLY gotten to a place where i can change an envisioned workout in order to keep working out, rather than obsessively have to stick with ONE routine because, who's keeping track again? oh? just me? right-o.
- doing short intervals with a heavy kb is an intriguing workout from both a cardiac and potential fuel burning perspective.
- remember to stash chalk at work, too: a few more minutes and that 24 would have been sailing out of the office towards the new building. Even though that's rather a pleasant thought - sort of like shooting a canon at an enemy battlement, the consequences would not be pretty.
- the snatch grip to avoid calluses in fast repeats is a skill to be learned - still
If you'd like more info on feeding up and why post workout, and what that has to do with muscles, here' a bit more in a review i did of precision nutrition's individualization/carb tolerance.
Now for the post happy lunch cup of tea... Tweet Follow @begin2dig
Friday, July 31, 2009
Fitness in 6 minutes of effort *a week* or Less? What does that mean? (Part I)
Follow @mcphoo
Tweet
If in a training session, we can hurl ourselves into short blasts of all out 
effort (without hurling), we may just be able to get ourselves fit in 6 (to 9) mins of effort a week. Fit, to the same level and kind of strength capacity if we were doing 2-3 hours traditional endurance work/week. While this sounds cool, what does 6 mins of fitness give us, especially, relative to any body comp and strength desires? This is part one of a two part article. Part I (what you're reading now): research review. Part II: plain language take aways form the research.
Background:
Last year when talking about the difference between cradio and vo2max training and the benefits thereof, especially for enhancing mitochondrial density, the stuff that makes fat burn in the cells, i mentioned this pretty new research out of (happiness and joy) Canada:
Here's the abstract
Now some folks may say ya ya, we know intervals are more efficient at burning calories than lower intensity steady state: more effort you burn more. Duh. But calories burned is not the big exciting part of this story. It's the mitochondria and the carbohydrates that are kinda amazing.
Getting Endurance Effects from Resistance Like Training?
One of the big reasons people blend HIIT with steady state lower intensity (65%) cardio training is both for (1) elasticity of heart muscle health that say resistance training alone doesn't give (pick up Kenneth Jay's Viking Warrior
Conditioning for more on this) and/or (2) creating cells that are better fat burners. Aerobic workouts both privilege fat as the fuel of choice AND they enhance the qualities of cells (mitochondria) that get fat oxidized (burned) for fuel.
Folks in the house who use kettlebells may be getting all smug here by saying that doing lots of swings with a mid sized bell does the endurance work, while all their presses, pulls and snatches takes care of the power/resistance stuff. Yes, it's a magic ball!
The thing is, again, the powerful finding of this work, is that it shows that that all important, highly sought-after mitochondria proliferation is occurring in super intense work in a way comparable to that 65% endurance work. That's not what we're doing in a ten minute swing set with a kb. And that's just not what would be predicted in the normal model of our metabolism. And here's why i love good science: the authors admit as much by saying they don't know why they are getting these results, citing that traditional and current understanding of strength/endurance
bodies work, these results shouldn't happen (and this is the second time the authors have repeated these results - in fact that they're getting similar effects in this 6 week trial as they did in their 2 week trial is provocative in itself).
In other words the 02 deficit may be SO HIGH after this effort your body may up-regulate O2 consumption afterwards, which impacts the aerobic system. So it might be the rest intervals during and post the effort where the aerobic ET-like adaptation is occurring.
What does that mean? Time to update the model - and consider all the variables that may play a role, from the brevity of the interval (longer may be counter-productive) to an understanding of the recovery period processes. The authors speculate that part of the answer is that the intensity of effort turns on a particular gene expression PGC-1α due to a whole bunch of upregulated muscular related fuel events that we'll skip here but that are triggered by this kind of intensity burst.
Indeed, in a study by Gibala that came out just this past June, 2009, the author came back to some of these questions. And that transcripter seems to be a winner. The abstract reads, in part,
Carbohydrate AND Phosphocreatine Sparing? What's new?
But let's come back to the other big finding of this study - less sensational, but good to confirm:
The usual model is that, going anaerobic - which an all out sprint effort does - means that we burn fuel from the phosphagen system in the initial blast and then we hit carbs. Phosphagen gives us a small burn of 10-30secs. After that, carbs kick in for about another three minutes of burn. Important to note is that we mean these are the primary fuel systems - oxygen (and so some fat burning) is always working too or we'd croak.
Part of the reason folks do vo2max training is to be carbohydrate sparing - we want to make the body able to use oxygen for greater levels of work, so that it turns to carbs at only higher and higher demands for fuel. Why would we want to do this? Two reasons: we have way more fat available for fuel than we do carbs, and fat gives way more energy bang for the buck than do carbs. In other words we can go longer on a gram of fat than we can a gram of carbs.
If you're doing weight loss work, naturally getting fat burning optimized is a good thing. This effect is again why folks traditionally do lower intensity cardio: it privileges fat burning for fuel.
Likewise in the strength training space, the reason we supplement with creatine is to help keep the phosphagen system topped up - so we can get a few more reps in at that higher phosphogen level fuel system going.
Now here's a protocol that says it's both beneficial for phosphocreatine and carbohydrate sparing. THat's not surprising for interval training to claim. That's part of the reason, as said, we do that with resistance work to develop power, and with vo2max work for higher endurance. The kicker here is the achievement of same with very low volume.
Here's how they tested it: they tested their SIT and ET groups prior to the study commencing with a 65% of pre-training v02peak effort of cycling for an hour. They did the same thing after 6 weeks. The researchers found again comparable changes in fuel usage in both groups so there were both carb and phosocreatine benefits from super low volume training.
The results may not be cost free, but the cost may be minimal or negligible. The amount of ATP at rest in the SIT group was lower; it didn't change in the ET group. This means that amount of available material to be used for muscle contraction was lower in the SIT group. The researchers aren't sure why this was the case: it takes awhile to reamp ATP and it may just be from residual effects of the last excercise bout before the samples were taken, or it may be an effect of the chronic excercise protocol. Not sure. Dunno. Watch that space.
So finally we can dump aerobics/cardio training?
If we get all the tasty goodness of aerobic trad endurance training from these brief moments of vomitus activity, can we skip cardio entirely? Answer: we don't know (did i say i love science yet?)
Is Even Less Even More?
Likewise, the current study measured 30s intervals for 6 mins of work. In a recent interview, Gibala said an upcoming study for fall 2009 will look at how low those intervals can go for benefit. Could a single two or three minute bout be as effective as those six minutes? Dunno!
A few Points on Gear.
I sense the kettlebeller within immediately wanting to give this protocol a go with kb snatching or some such. An important note, then.
The study was carried out on a stationary bike. That's the typical device for a wingate test. It's safe. Swimming is another safe place (no pounding for all those repeats) where one can get one's heart and system up to that intensity - though swimming is harder to gate. Easier on a bike.
The wingate test is a precisely set load on the individual: from .075kg/kg of athlete to 1.3kg/kg of athlete. It would be interesting to think about how to translate this kind of resistance to a *safe* kettlebell routine.
Of course the disadvantage of thinking about such a rep set might be that one's form goes to hell, and that's totally wrong, engraining poor rep quality is rather problematic neurologically not always to be going for a perfect rep.
A few questions about fitness and body comp
Most of us workout because we want to be strong and look half decent half dressed. What this study did not measure is what these results mean for the technical body comp (bf%, say) and the visual body comp (dress size, look in the mirror, buff-ness).
For instance, in a study from 2007, it seemed that for folks to maintain their desired body look and feel, they needed to workout for 5 hours a week, mixing up cardio, intervals and strength work.
Now while this study protocol hasn't been put forward as a training program that's sorta where the NYT interview, cited above, was coming from, and it's certaininly an interest of the folks doing the studies.
But the question might be, given body comp and strength goals, what would this 6 mins a week fitness regine get those of us who are, well, already fit enough to contemplate it?
Part II: What does this all really mean for our actual real workouts? 6 plain language take aways, next.
Burgomaster, K., Howarth, K., Phillips, S., Rakobowchuk, M., MacDonald, M., McGee, S., & Gibala, M. (2007). Similar metabolic adaptations during exercise after low volume sprint interval and traditional endurance training in humans The Journal of Physiology, 586 (1), 151-160 DOI: 10.1113/jphysiol.2007.142109 Tweet Follow @begin2dig
If in a training session, we can hurl ourselves into short blasts of all out effort (without hurling), we may just be able to get ourselves fit in 6 (to 9) mins of effort a week. Fit, to the same level and kind of strength capacity if we were doing 2-3 hours traditional endurance work/week. While this sounds cool, what does 6 mins of fitness give us, especially, relative to any body comp and strength desires? This is part one of a two part article. Part I (what you're reading now): research review. Part II: plain language take aways form the research.Background:
Last year when talking about the difference between cradio and vo2max training and the benefits thereof, especially for enhancing mitochondrial density, the stuff that makes fat burn in the cells, i mentioned this pretty new research out of (happiness and joy) Canada:
Here's the abstract
Low-volume 'sprint' interval training (SIT) stimulates rapid improvements in muscle oxidative capacity that are comparable to levels reached following traditional endurance training (ET) but no study has examined metabolic adaptations during exercise after these different training strategies. We hypothesized that SIT and ET would induce similar adaptations in markers of skeletal muscle carbohydrate (CHO) and lipid metabolism and metabolic control during exercise despite large differences in training volume and time commitment. Active but untrained subjects (23 ± 1 years) performed a constant-load cycling challenge (1 h at 65% of peak oxygen uptakeOn the face of it, the big take away from the study, as the authors say themselves in the Discussion part of the article: the effect on carbs in the muscle and fat metabolism were comparable to the endurance training protocols, and here's the kickerbefore and after 6 weeks of either SIT or ET (n= 5 men and 5 women per group). SIT consisted of four to six repeats of a 30 s 'all out' Wingate Test (mean power output ∼500 W) with 4.5 min recovery between repeats, 3 days per week. ET consisted of 40–60 min of continuous cycling at a workload that elicited ∼65%
(mean power output ∼150 W) per day, 5 days per week. Weekly time commitment (∼1.5 versus∼4.5 h) and total training volume (∼225 versus∼2250 kJ week
−1 ) were substantially lower in SIT versus ET. Despite these differences, both protocols induced similar increases
Similar metabolic adaptations during exercise after low volume sprint interval and traditional endurance training in humans
Pages: 151–160
Kirsten A. Burgomaster, Krista R. Howarth, Stuart M. Phillips, Mark Rakobowchuk, Maureen J. MacDonald, Sean L. McGee, Martin J. Gibala
Published Online: Jan 2 2008 12:00AM
DOI: 10.1113/jphysiol.2007.142109
quick note on terms: vo2peak is highest VO2 elicited in test to exhaustion; the more familiar vo2max which is the plateau hit for V02 when adding progressive load. So you can readily hit vo2max before exhaustion.
despite a much lower training volume and time commitment. By design, weekly training volume was ∼90% lower in the SIT group (∼225 versus∼2250 kJ week90% lower! in terms of time and effort. So, low volume (few repeats) of maximal effort with good recovery has the same effect as high volume mid intenstity.−1 for ET) and necessitated a training time commitment that was only ∼one-third of that of the ET group (∼1.5 versus 4.5 h [over 6 weeks -mc]).
Now some folks may say ya ya, we know intervals are more efficient at burning calories than lower intensity steady state: more effort you burn more. Duh. But calories burned is not the big exciting part of this story. It's the mitochondria and the carbohydrates that are kinda amazing.
Getting Endurance Effects from Resistance Like Training?
One of the big reasons people blend HIIT with steady state lower intensity (65%) cardio training is both for (1) elasticity of heart muscle health that say resistance training alone doesn't give (pick up Kenneth Jay's Viking Warrior
Conditioning for more on this) and/or (2) creating cells that are better fat burners. Aerobic workouts both privilege fat as the fuel of choice AND they enhance the qualities of cells (mitochondria) that get fat oxidized (burned) for fuel.Folks in the house who use kettlebells may be getting all smug here by saying that doing lots of swings with a mid sized bell does the endurance work, while all their presses, pulls and snatches takes care of the power/resistance stuff. Yes, it's a magic ball!
The thing is, again, the powerful finding of this work, is that it shows that that all important, highly sought-after mitochondria proliferation is occurring in super intense work in a way comparable to that 65% endurance work. That's not what we're doing in a ten minute swing set with a kb. And that's just not what would be predicted in the normal model of our metabolism. And here's why i love good science: the authors admit as much by saying they don't know why they are getting these results, citing that traditional and current understanding of strength/endurance
In other words (i love good science, did i say that?) given what we've understood about how our
While the present study demonstrates the potency of SIT [sprint interval training -mc] to elicit changes in muscle oxidative capacity and selected metabolic adjustments during exercise that resemble ET [endurance training -mc], the underlying mechanisms are unclear. From a cell signalling perspective, exercise is typically classified as either 'strength' or 'endurance', with short-duration, high-intensity work usually associated with increased skeletal muscle mass, and prolonged, low- to moderate-intensity work associated with increased mitochondrial mass and oxidative enzyme activity (Baar, 2006).
bodies work, these results shouldn't happen (and this is the second time the authors have repeated these results - in fact that they're getting similar effects in this 6 week trial as they did in their 2 week trial is provocative in itself).In other words the 02 deficit may be SO HIGH after this effort your body may up-regulate O2 consumption afterwards, which impacts the aerobic system. So it might be the rest intervals during and post the effort where the aerobic ET-like adaptation is occurring.
What does that mean? Time to update the model - and consider all the variables that may play a role, from the brevity of the interval (longer may be counter-productive) to an understanding of the recovery period processes. The authors speculate that part of the answer is that the intensity of effort turns on a particular gene expression PGC-1α due to a whole bunch of upregulated muscular related fuel events that we'll skip here but that are triggered by this kind of intensity burst.
Indeed, in a study by Gibala that came out just this past June, 2009, the author came back to some of these questions. And that transcripter seems to be a winner. The abstract reads, in part,
A key controller of oxidative enzyme expression in skeletal muscle is peroxisome proliferator-activated receptor gamma coactivator 1alpha (PGC-1alpha), a transcriptional coactivator that serves to coordinate mitochondrial biogenesis...Signaling through AMP-activated protein kinase and p38 mitogen-activated protein kinase to PGC-1alpha may therefore explain, in part, the metabolic remodeling induced by HIT, including mitochondrial biogenesis and an increased capacity for glucose and fatty acid oxidation.The conclusion comes away saying that this KIND (and potentially duration) of interval has magical properties that blend endurance benefits for mitochondria building while being what looks like resistance training:
High-intensity interval exercise represents a unique and understudied model for examining the molecular regulation of skeletal muscle remodeling. Like strength or resistance training, interval exercise is characterized by brief intermit- tent bouts of relatively intense muscle contraction. However, interval exercise training induces phenotypic changes that resemble those elicited after traditional endurance training. Preliminary evidence suggests that signaling through AMPK and p38 MAPK to PGC-1a may explain, in part, the meta- bolic adaptations induced by HIT, including mitochondrial biogenesis and an increased capacity for glucose and fatty acid oxidation.In other words, turning on PGC-1a is a big deal to generating this remodeling. And we know from the other studies - or at least strongly suspect - that it's hitting high intensity for these short blasts that does the turning on.
Carbohydrate AND Phosphocreatine Sparing? What's new?
But let's come back to the other big finding of this study - less sensational, but good to confirm:
The usual model is that, going anaerobic - which an all out sprint effort does - means that we burn fuel from the phosphagen system in the initial blast and then we hit carbs. Phosphagen gives us a small burn of 10-30secs. After that, carbs kick in for about another three minutes of burn. Important to note is that we mean these are the primary fuel systems - oxygen (and so some fat burning) is always working too or we'd croak.
Part of the reason folks do vo2max training is to be carbohydrate sparing - we want to make the body able to use oxygen for greater levels of work, so that it turns to carbs at only higher and higher demands for fuel. Why would we want to do this? Two reasons: we have way more fat available for fuel than we do carbs, and fat gives way more energy bang for the buck than do carbs. In other words we can go longer on a gram of fat than we can a gram of carbs.
If you're doing weight loss work, naturally getting fat burning optimized is a good thing. This effect is again why folks traditionally do lower intensity cardio: it privileges fat burning for fuel.
Likewise in the strength training space, the reason we supplement with creatine is to help keep the phosphagen system topped up - so we can get a few more reps in at that higher phosphogen level fuel system going.Now here's a protocol that says it's both beneficial for phosphocreatine and carbohydrate sparing. THat's not surprising for interval training to claim. That's part of the reason, as said, we do that with resistance work to develop power, and with vo2max work for higher endurance. The kicker here is the achievement of same with very low volume.
Here's how they tested it: they tested their SIT and ET groups prior to the study commencing with a 65% of pre-training v02peak effort of cycling for an hour. They did the same thing after 6 weeks. The researchers found again comparable changes in fuel usage in both groups so there were both carb and phosocreatine benefits from super low volume training.
The results may not be cost free, but the cost may be minimal or negligible. The amount of ATP at rest in the SIT group was lower; it didn't change in the ET group. This means that amount of available material to be used for muscle contraction was lower in the SIT group. The researchers aren't sure why this was the case: it takes awhile to reamp ATP and it may just be from residual effects of the last excercise bout before the samples were taken, or it may be an effect of the chronic excercise protocol. Not sure. Dunno. Watch that space.
So finally we can dump aerobics/cardio training?
If we get all the tasty goodness of aerobic trad endurance training from these brief moments of vomitus activity, can we skip cardio entirely? Answer: we don't know (did i say i love science yet?)
It is also important to stress that the relatively limited array of metabolic measurements performed in the present study may not be representative of other physiological adaptations normally associated with ET. For example, SIT may differ from ET with respect to changes induced in the cardiovascular and respiratory systems, metabolic control in other organs (e.g. liver or adipose tissue) and protection from various factors associated with chronic inactivity (e.g. insulin resistance or lipid dysregulation).Indeed, with respect to the all important insulin, and the goal of building insulin sensitivity, in another June 09 publication, Hawley and Gibala look at insulin intensity and exercise intensity and ask "how low can you go?" The authors wanted to get as close as current research findings, when synthesized, might suggest, how *intense* does exercise need to be to have a beneficial effect on insulin sensitivity. Conclusions so far?
It remains to be determined whether high-intensity, low-volume interval training protocols can confer all of the health-related benefits associated with less intense, more prolonged traditional endurance training programmes. [Based on the review of literature to date, however -mc] it seems prudent to recommend that, for patients with insulin resistance or type 2 diabetes, the minimal dose of physical activity needed to maintain or improve health is equivalent to ~4,000 kJ/week of low- to moderate-intensity exercise. However, for patients who only show modest improvements in clinical and metabolic outcomes at this level of activity-induced energy expenditure, an increase in the intensity of exercise may be considered because of the potential additional benefits in both metabolic control and cardiorespiratory fitness.In other words going all out with sprint intervals is not for everyone or all conditions.
Is Even Less Even More?
Likewise, the current study measured 30s intervals for 6 mins of work. In a recent interview, Gibala said an upcoming study for fall 2009 will look at how low those intervals can go for benefit. Could a single two or three minute bout be as effective as those six minutes? Dunno!
A few Points on Gear.
I sense the kettlebeller within immediately wanting to give this protocol a go with kb snatching or some such. An important note, then.
The study was carried out on a stationary bike. That's the typical device for a wingate test. It's safe. Swimming is another safe place (no pounding for all those repeats) where one can get one's heart and system up to that intensity - though swimming is harder to gate. Easier on a bike.
The wingate test is a precisely set load on the individual: from .075kg/kg of athlete to 1.3kg/kg of athlete. It would be interesting to think about how to translate this kind of resistance to a *safe* kettlebell routine.Of course the disadvantage of thinking about such a rep set might be that one's form goes to hell, and that's totally wrong, engraining poor rep quality is rather problematic neurologically not always to be going for a perfect rep.
A few questions about fitness and body comp
Most of us workout because we want to be strong and look half decent half dressed. What this study did not measure is what these results mean for the technical body comp (bf%, say) and the visual body comp (dress size, look in the mirror, buff-ness).
For instance, in a study from 2007, it seemed that for folks to maintain their desired body look and feel, they needed to workout for 5 hours a week, mixing up cardio, intervals and strength work.
Now while this study protocol hasn't been put forward as a training program that's sorta where the NYT interview, cited above, was coming from, and it's certaininly an interest of the folks doing the studies.But the question might be, given body comp and strength goals, what would this 6 mins a week fitness regine get those of us who are, well, already fit enough to contemplate it?
Part II: What does this all really mean for our actual real workouts? 6 plain language take aways, next.
Burgomaster, K., Howarth, K., Phillips, S., Rakobowchuk, M., MacDonald, M., McGee, S., & Gibala, M. (2007). Similar metabolic adaptations during exercise after low volume sprint interval and traditional endurance training in humans The Journal of Physiology, 586 (1), 151-160 DOI: 10.1113/jphysiol.2007.142109 Tweet Follow @begin2dig
Sunday, November 30, 2008
Does Cardio Interfere with Strength Training? How 'bout "no."
Follow @mcphoo
Tweet
A question that strength trainees ask at some point:
doesn't endurance (cardio) training interfere with strength training?
Great Question: Initially, starting in 1980 with Hickson, continuing through the 90's, as described in this super review by Andrew Burne, the answer was pretty much "yes."
Even more recent literature still seems to show that there is some interference effect, depending on volume/intensity of the types of training. More recently (2006) there has been a super article that says, ok, based on the findings that more consistently than not show an impact on explosive resistance training, let's consider what the molecular mechanisms are that may be involved to better tune training.
There's a couple new studies, however, lead by Davis [1][2] that revisits this issue of assumed "interference." These studies are interesting on their own, but are particularly useful for reviewing the key ideas around when and how interference happens, if it happens, and why keeping that VO2max KB work in with the strength program is a Good Thing - though there's some other mixes that may have awesome results, too.
Davis is the researcher who in Jan 2008 showed that the effect on delayed onset muscle soreness (DOMS) can be mitigated by doing some cardio between sets (consider accelerated fast and loose) rather than just resting. He and his group seem to be applying similar protocols to strength training. That is, in the first Davis study, he had a group do serial concurrent exercise protocols (CE = strength and endurance) and what he defines as "integrated." Serial means that the group did their resistance training, then they did their aerobic stuff. The participants rested between sets of their lifts. Pretty standard prescription.
In the "integrated" version, participants did their aerobic work *during* their lifts, effectively between sets. Their heart rates were significantly higher across the complete period of their resistance trainng than their serial colleagues. This is not standard. How many times have you heard "leave your cardio till after your workout; you'll tire yourself out and won't be able to lift"
Here's the kicker: the results. First, the cool thing is we're talking well conditioned participants, not newbies (what i don't know is if they're new to resistance though), but second, the results will surprise you: the mean lower body strength of the serial group went up 17.2%. Not bad at all. The mean lower body strength of the integrated group, however, went up 23.3%. Intriguingly, gains in UPPER body strength were higher in the Serial group than the integrated. As for Endurance, both groups made big improvements; the integrated made more. As for body composition, not surprisingly perhaps, the integrated group was significantly better: 3.3% for integrated, vs 1.8% for serial.
The main take away, according to the authors, is that when compared to single mode training for strength, the concurrent exercise, both serial and integrated, made as good or better gains than single mode. So take that, interference ideas. Also, that by going "integrated" the gains across every marker (but upper body strength), were better in integrated practice.
A cool thing also shown is that there seems to be considerable benefit to strength by adding a Range of Motion cool down, rather than just strength work alone (if you don't have ROM work, consider some zhealth (overview of Z)).
The overview of interference by the authors:
Ok, i'll go along with the study showed that there were benefits of adding vigorous cardio (and ROM cool down) to strength. Great. It's also pretty clear that keeping your heart rate up (not resting between sets) is also a benefit to strength. This approach well supports and advances what Pavel's written about not sitting down between sets but keeping your heart up (see Enter The Kettlebell (review) as an example with its discussion of what to do between sets), though the rationale there was not particularly because it *improved* strength gains or reduced DOMS (as far as i recall, anyway).
What i don't quite see tested, and so not supported in the article is the critical issue of frequency. The authors claim that their work is "consistent" with other research on frequency. Which? the work that has shown that negative impacts with more days a week vs fewer days a week? or work that showed even low doses were troubling? The authors picked a nice middle-of-the-road protocol of 3 days a week for training and ONLY three days a week and got nice results.
We do know, that for whatever the myriad of factors, total density of training is a factor in any training plan, balancing recovery and effort, as Kenneth Jay keeps telling me, more an art than a strict science. It's not hard to believe, therefore, that tagging on additional effort to an already loaded program, could have a negative impact, whether resistance or cardio.
So why might the "integrated" approach be a goodie? Davis et al don't know. They have a really neat hypothesis, though, related to their earlier work on "cardioaccleration" and DOMS (remember, they found doing cardio between sets reduced DOMS).
When the DOMS article first came out, colleagues said they wouldn't want to sacrifice performance just to reduce DOMS - in other words the cardio during resistance would take away from the effort they could put in - they hypothesized. This latest study shows the reverse seems to be the case.
What does this CE result mean for our training?
So for folks who have been mixing up or integrating strength and intense cardio already (see the end of the Cardio/VO2Max article for examples of such protocols), this research just seems to add more support for the value of the approach for strength. What this result means for the rest of us? Well balanced CE programs are better for strength than strength training alone. Tweet Follow @begin2dig
doesn't endurance (cardio) training interfere with strength training?
Great Question: Initially, starting in 1980 with Hickson, continuing through the 90's, as described in this super review by Andrew Burne, the answer was pretty much "yes."
Even more recent literature still seems to show that there is some interference effect, depending on volume/intensity of the types of training. More recently (2006) there has been a super article that says, ok, based on the findings that more consistently than not show an impact on explosive resistance training, let's consider what the molecular mechanisms are that may be involved to better tune training.There's a couple new studies, however, lead by Davis [1][2] that revisits this issue of assumed "interference." These studies are interesting on their own, but are particularly useful for reviewing the key ideas around when and how interference happens, if it happens, and why keeping that VO2max KB work in with the strength program is a Good Thing - though there's some other mixes that may have awesome results, too.
Davis is the researcher who in Jan 2008 showed that the effect on delayed onset muscle soreness (DOMS) can be mitigated by doing some cardio between sets (consider accelerated fast and loose) rather than just resting. He and his group seem to be applying similar protocols to strength training. That is, in the first Davis study, he had a group do serial concurrent exercise protocols (CE = strength and endurance) and what he defines as "integrated." Serial means that the group did their resistance training, then they did their aerobic stuff. The participants rested between sets of their lifts. Pretty standard prescription.
In the "integrated" version, participants did their aerobic work *during* their lifts, effectively between sets. Their heart rates were significantly higher across the complete period of their resistance trainng than their serial colleagues. This is not standard. How many times have you heard "leave your cardio till after your workout; you'll tire yourself out and won't be able to lift"
Here's the kicker: the results. First, the cool thing is we're talking well conditioned participants, not newbies (what i don't know is if they're new to resistance though), but second, the results will surprise you: the mean lower body strength of the serial group went up 17.2%. Not bad at all. The mean lower body strength of the integrated group, however, went up 23.3%. Intriguingly, gains in UPPER body strength were higher in the Serial group than the integrated. As for Endurance, both groups made big improvements; the integrated made more. As for body composition, not surprisingly perhaps, the integrated group was significantly better: 3.3% for integrated, vs 1.8% for serial.
The main take away, according to the authors, is that when compared to single mode training for strength, the concurrent exercise, both serial and integrated, made as good or better gains than single mode. So take that, interference ideas. Also, that by going "integrated" the gains across every marker (but upper body strength), were better in integrated practice.
A cool thing also shown is that there seems to be considerable benefit to strength by adding a Range of Motion cool down, rather than just strength work alone (if you don't have ROM work, consider some zhealth (overview of Z)).
The overview of interference by the authors:
- Many studies have postulated that training frequency is a variable as to whether or not interference occurs. There's nothing conclusive: "Evidence for the training frequency hypothesis is therefore suggestive but equivocal."
- Poor (untrained) physical condition of participants in studies has also been suggested as a factor for interference (or not) "Most studies cited here that report interference from CE used untrained or sedentary subjects, whereas most studies cited here that report absence of interference or synergy used well-trained subjects. Studies reporting absence of interference or synergy in medium- to high-frequency concurrent training protocols invariably used well-conditioned subjects" Most of these studies looked at effects on endurance athletes, it seems, not the other way around, and that's where the money is for most strength athletes like hard style kettlebellers.
- The usual hypothesis that timing of aerobic vs resistance work is a key factor, eg aerobics before, after or during resistance, isn't well established either. "The few studies that have evaluated exercise timing and sequence during concurrent training therefore suggest a possible effect, but its nature and prerequisites are unclear."
Ok, i'll go along with the study showed that there were benefits of adding vigorous cardio (and ROM cool down) to strength. Great. It's also pretty clear that keeping your heart rate up (not resting between sets) is also a benefit to strength. This approach well supports and advances what Pavel's written about not sitting down between sets but keeping your heart up (see Enter The Kettlebell (review) as an example with its discussion of what to do between sets), though the rationale there was not particularly because it *improved* strength gains or reduced DOMS (as far as i recall, anyway).
What i don't quite see tested, and so not supported in the article is the critical issue of frequency. The authors claim that their work is "consistent" with other research on frequency. Which? the work that has shown that negative impacts with more days a week vs fewer days a week? or work that showed even low doses were troubling? The authors picked a nice middle-of-the-road protocol of 3 days a week for training and ONLY three days a week and got nice results.
We do know, that for whatever the myriad of factors, total density of training is a factor in any training plan, balancing recovery and effort, as Kenneth Jay keeps telling me, more an art than a strict science. It's not hard to believe, therefore, that tagging on additional effort to an already loaded program, could have a negative impact, whether resistance or cardio.
So why might the "integrated" approach be a goodie? Davis et al don't know. They have a really neat hypothesis, though, related to their earlier work on "cardioaccleration" and DOMS (remember, they found doing cardio between sets reduced DOMS).
[T]he time course of DOMS reduction and elimination in both men and women trained in the integrated CE protocol is similar to the known time course of skeletal muscle angiogenesis, which may increase muscle perfusion during resistance exercise in the integrated CE group. The same mechanism could account for the apparent synergy of strength and endurance training in the integrated CE group. DOMS signifies contraction-induced muscle damage and consequent reduced capacity to generate muscular power for up to 72 hours (60), implying reduced responsiveness to strength training even in low-frequency (2 days per week) training protocols, whereas enhanced muscle perfusion increases muscle performance by up to 20% (44). The elimination of DOMS and consequent faster muscle recovery combined with enhanced muscle perfusion in the integrated CE protocol could therefore increase training adaptations compared with the serial CE protocol, as found in the present study, perhaps through the mechanism of enhanced postactivation potentiation of muscle responses to resistance exercises (11,12).In other words, their integrated approach is reducing DOMS which means faster recovery, which means accelerated growth/performance.
When the DOMS article first came out, colleagues said they wouldn't want to sacrifice performance just to reduce DOMS - in other words the cardio during resistance would take away from the effort they could put in - they hypothesized. This latest study shows the reverse seems to be the case.
What does this CE result mean for our training?
Enhanced training adaptations from integrated CE, combined with the potentially related elimination of DOMS (15) and consequent faster muscle recovery (21), therefore have the potential to improve training and clinical outcomes in exercise programs at all levels.It's worth looking at the article for exactly what intensity is being described in the CE protocol. Saying that, one of the big takeaways from the study is that, if the frequency is right (don't overdo your training. duh), and if you're already well conditioned, intense cardio + resistance are better for strength than strength work alone. If you want to take these benefits further, and enhance recovery, there's an opportunity to "integrate" resistance and "vigorous" / intense cardio.
So for folks who have been mixing up or integrating strength and intense cardio already (see the end of the Cardio/VO2Max article for examples of such protocols), this research just seems to add more support for the value of the approach for strength. What this result means for the rest of us? Well balanced CE programs are better for strength than strength training alone. Tweet Follow @begin2dig
Subscribe to:
Posts (Atom)
COACHING with dr. m.c. 
