Thursday, May 20, 2010
Excessive Daytime Sleepiness - Can be a Big Issue predictor.
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Sleep is so important. Sleepiness during the day may likewise be a really critical health marker. Sleepiness itself is usually taken as a sign that we just didn't get enough kip. Sometimes figuring out why is easy, and we can fix it; sometimes figuring out why is a little more elusive, and getting some knowledgable help is a great idea. Note: if you're considering seeing a trainer or coach, find out from them what kind of HISTORY they take about your wellbeing. If there's nothing in there about the qualities of what i've been calling our H2 Ratio, you may want to have a chat with someone else.
We know that chronic sleepiness in"older adults", is a marker of potential heart issues and mortality risk. It also seems to show up some specific correlations around mental and physical well being too.
While doing some work on sleep in our lab project on personal wellbeing tracking, i came across the following studies on EDS (excessive daytime sleepiness). The first is EDS as a marker of risk for "older adults"
Why folks feel sleepy during the day we know may stem from multiple causes. Nutrition issues, pain, breathing difficulties, lack of movement during the day, medication, sleep disorders. But it seems one of the highlights from this article is that it's REALLY IMPORTANT that if one is chronically sleepy, it's more than a good idea to check in about what might be causing that sleepiness and get it addressed.
Likewise, a more recent study looked at quality of life responses across ethnic groups relative to sleep disturbances/EDS. Here's what they report.
So as with the "older adult" study, sleep issues may be showing up as a consequence of related factors. THat's not a particular surprise. What we do know, however, is that crappy sleep in itself - that can show up as excessive daytime sleepiness too - is not good for health. We need quality z's.
A recent survey of evaluation approaches shows there are LOTS of ways to check in with a person about possible causes and developing a strategy towards getting better sleep. And, if you're interested more generally in what sleep is, and what some known sleep issues are, there's a nice current overview - free paper - called simply "Overview of sleep & sleep disorders."
Sleep Practice Feedback. In my group, we're doing research looking at the role awareness may play in wellbeing, health, quality of life. One of the devices we're using as a feed for the data is the Zeo. I've written about this before with a two part interview with Stephen Fabregas, sleep researcher, at Zeo. I'm also in the throes of prepping a review of using the device.
[EDIT - 2013: unfortunately the following kit is no longer available as zeo has closed down. THere are simple sleep monitors in commercial hardware like FitBit and Jawbone UP and also free actigarphy monitors on many phone platforms: these at least give an indication of time in bed/asleep and time restless. it's all about trends...]
Early summary: i really like it, and yes it's helped modify my behaviour to get better quality sleep. Why? because i can *see* it - my sleep cycles - i want to understand why i had less deep sleep or what's going on with low REM compared to how i usually sleep. What's different? Pretty simply it gives me a way to help make more grounded sense of how i'm doing. And it's making a difference.
There's also a sleep coach program that i'm just getting into, so that's why the review is not out yet - i want to see what that does, too. But even without the sleep coach, this device, compared with all the sleep info on the site, has been making a real difference to my perceived well being.
If you're interested, Zeo is offering a 10dollar off/free shipping deal with a coupon (here's the link). As said, i like it. I'm learning a lot. And am using it more than i do a heart rate monitor right now perhaps because this is such a new area of investigation for me.
Now, getting a zeo is not a replacement at all if one is suffering from excessive daytime sleepiness or related sleep issues in sitting down with a health pro to find out what may be going on with one's sleep - if there is some disease or drug or related Big Deal happening that requires attention. And sleep, as stephan said in the interviews, is SO crucial, and as the above research shows it's critical to get on top of it.
What a zeo can do is reflect back, pretty clearly, if those strategies are working, and if so, how well. That wee display can also help keep us honest about our practice, and help us tune that practice. So it's no replacement for real counciling (nor is it designed to be) around a chronic issue, but it's a great way to help dial in and feedback the practice.
For instance, some of the quesitons i've had are: all things being equal, does timing of exercise in the evening REALLY effect my sleep quality? Does doing two split workouts a day do better than one? Can i really see any difference on fasting or better quality eating days? Very personal tuning to be sure, but it wasn't really possible to ask these quesitons previously as i had no real, clear way of correlating sleep with these practices. There's a section on the site "for health pros" that lists the research on this puppy.
Summary: Daytime sleepiness especially if it starts to become a pattern is NOT a good thing. It's associated with everything from poor mental health to, well, death. So, it's very much worth getting sleep quality up (and daytime sleepiness down). Sleepiness during the day, especially in older adults, seems to be a strong marker of a potential issue.
If general healthy sleep practices aren't working, checking in with a health professional like one's GP about what factors may be influencing it, and getting on top of it, are really important. It's awful to have health issues already where more will be amplified by poor sleep. A vicious cycle that needs to be broken. A sleep monitor tool in these cases to give good feedback on how well strategies, once they've been developed, are working.
Absolutely check with your GP; if you are not being physical yet, getting one with starting movement can be a HUGE boon. Here's an overview of getting some Time under Movement
If you are already moving and experiencing sleepiness, working with a qualified practitioner /coach who can look at your movement, nutrition, sleep and related is a Good Thing. I personally work with folks in consultation with their GP's assessments. They go great together.
But main takeaway: chronic daytime sleepiness - it's our bodies talking to us in a BIG WAY to say something needs to change. Seek help in figuring out what things to tune and how. You'll love how you feel.
Citations
Sleep is so important. Sleepiness during the day may likewise be a really critical health marker. Sleepiness itself is usually taken as a sign that we just didn't get enough kip. Sometimes figuring out why is easy, and we can fix it; sometimes figuring out why is a little more elusive, and getting some knowledgable help is a great idea. Note: if you're considering seeing a trainer or coach, find out from them what kind of HISTORY they take about your wellbeing. If there's nothing in there about the qualities of what i've been calling our H2 Ratio, you may want to have a chat with someone else.We know that chronic sleepiness in"older adults", is a marker of potential heart issues and mortality risk. It also seems to show up some specific correlations around mental and physical well being too.
While doing some work on sleep in our lab project on personal wellbeing tracking, i came across the following studies on EDS (excessive daytime sleepiness). The first is EDS as a marker of risk for "older adults"
J Am Geriatr Soc. 2000 Feb;48(2):115-23.
Daytime sleepiness predicts mortality and cardiovascular disease in older adults. The Cardiovascular Health Study Research Group.
Newman AB, Spiekerman CF, Enright P, Lefkowitz D, Manolio T, Reynolds CF, Robbins J. University of Pittsburgh, Pennsylvania 15213, USA.
INTRODUCTION: As part of the baseline examination in the Cardiovascular Health Study, sleep disturbance symptoms including snoring and daytime sleepiness, were assessed as potential risk factors or precipitants of cardiovascular disease (CVD). Because of the association of sleep disturbance with poorer health and the possible associations of sleep apnea with CVD, we hypothesized that those with poorer sleep or daytime sleepiness may be at increased risk of mortality or incident CVD. SETTING: Participants (n = 5888) were recruited in 1989, with an additional minority cohort recruited in 1993, in four US communities for a cohort study designed to evaluate risk factors for cardiovascular disease. METHODS: An interview-administered questionnaire regarding health and sleep habits with ongoing ascertainment of total mortality and cardiovascular disease morbidity and mortality, including total CVD morbidity and mortality, incident myocardial infarction, and congestive heart failure. RESULTS: Daytime sleepiness was the only sleep symptom that was significantly associated with mortality in both men and women. The unadjusted hazard ratio was 2.12 (1.66, 2.72) in women and 1.40 (1.12, 1.73) in men. Men who reported difficulty falling asleep also had an increased mortality rate (HR = 1.43 (1.14, 1.80)) which was not seen in women. The risks were attenuated with adjustment for age but remained significant for daytime sleepiness in women (HR = 1.82 (1.42, 2.34)) and for difficulty falling asleep in men. (HR = 1.29 (1.03, 1.63)). Frequent awakenings, early morning awakening, and snoring were not associated with a significantly increased risk of mortality in these older men and women. Crude event rates were evaluated for total incident cardiovascular morbidity and mortality, incident myocardial infarction, and incident congestive heart failure (CHF). Incident CVD rates were higher in both men and women with daytime sleepiness. The aged adjusted HR was 1.35 (95% CI = 1.03, 1.76) in men and was 1.66 (95% CI = 1.28, 2.16) in women. Incident CVD was not higher in those with any other sleep disturbance including snoring. The risk of CVD events associated with daytime sleepiness was attenuated but remained significant in women after adjustment for age. Incident myocardial infarction (MI) rates were also higher in women with daytime sleepiness but were not significantly higher in men. Incident CHF rates were increased in both men and women with daytime sleepiness. In men, the age adjusted HR was 1.49 (95% CI, 1.12- 1.98) and in women, was 2.21 (95% CI, 1.64-2.98). Women reporting both daytime sleepiness and frequent awakening had a hazard ratio of 2.34 (95% CI, 1.66-3.29) for incident CHF compared with those with daytime sleepiness but without frequent awakening. This interaction was not found in men. CONCLUSIONS: In this study, daytime sleepiness was the only sleep disturbance symptom that was associated with mortality, incident CVD morbidity and mortality, MI, and CHF. These findings were stronger in women than men, i.e., the associations persisted for mortality, CVD, and CHF in women after adjustment for age and other factors. Thus, a report of daytime sleepiness identifies older adults at increased risk for total and cardiovascular mortality, and is an independent risk factor in women.The big deal here is the end of this abstract - the signs being described have much the ring of metabolic syndrome to them, don't they?
Why folks feel sleepy during the day we know may stem from multiple causes. Nutrition issues, pain, breathing difficulties, lack of movement during the day, medication, sleep disorders. But it seems one of the highlights from this article is that it's REALLY IMPORTANT that if one is chronically sleepy, it's more than a good idea to check in about what might be causing that sleepiness and get it addressed.
Likewise, a more recent study looked at quality of life responses across ethnic groups relative to sleep disturbances/EDS. Here's what they report.
J Clin Sleep Med. 2010 Apr 15;6(2):176-83.What the study suggests is that sleep disturbances and results like excessive daytime sleepiness (25% of the total cohort of over 5000 participants) seem to correlate with different effects on mental/physical health relative to (a) US Norms and (b) ethnicity. A key conclusion, however, is that, while these results are indicative, they may be part of "comorbid health conditions" - in other words, the sleep related problems and their associated responses may be part of a package of issues.
Sleep disturbances, quality of life, and ethnicity: the Sleep Heart Health Study.
Baldwin CM, Ervin AM, Mays MZ, Robbins J, Shafazand S, Walsleben J, Weaver T.
Arizona State University College of Nursing and Health Innovation, Phoenix, AZ 85004, USA. carol.baldwin@asu.edu
Abstract
STUDY OBJECTIVES: To compare health-related quality of life (HR-QOL) across subgroups defined by sleep disturbances and ethnicity. METHODS: Men (47%) and women (53%) Sleep Heart Health Study participants age 40 and older (N = 5237) underwent overnight polysomnography and completed self-report questionnaires on symptoms of sleep disturbances. The physical and mental composite scales (PCS and MCS) of the Medical Outcomes Study 36-item short form survey assessed HR-QOL and were compared to sleep data. RESULTS: Participants self-identified as Caucasian/White (n = 4482, 86%), African American/Black (n = 490, 9%), or Hispanic/Mexican American (n = 265, 5%). The prevalence of obstructive sleep apnea (OSA) was 17%, frequent snoring was 34%, difficulty initiating or maintaining sleep (DIMS; insomnia symptoms) was 30%, and excessive daytime sleepiness (EDS) was 25%. African American participants with frequent snoring, insomnia symptoms, or EDS had significantly poorer physical health compared to Caucasians (p < 0.001). Hispanics with frequent snoring, insomnia symptoms, or EDS had significantly poorer mental health than Caucasian participants (p <0.001). Neither PCS nor MCS scores differed significantly across ethnic subgroups for participants with moderate to severe OSA (respiratory disturbance index > 15, 4% desaturation). CONCLUSIONS: Across ethnic/racial subgroups, sleep disturbances are associated with worse physical and better mental HR-QOL than the U.S. norm, but this relationship may be moderated by comorbid health conditions. This study replicates and extends prior research indicating differences among minority and non-minority participants and highlights the need for future studies of sleep disturbances with larger samples of minorities that control for comorbid health conditions.
So as with the "older adult" study, sleep issues may be showing up as a consequence of related factors. THat's not a particular surprise. What we do know, however, is that crappy sleep in itself - that can show up as excessive daytime sleepiness too - is not good for health. We need quality z's.
A recent survey of evaluation approaches shows there are LOTS of ways to check in with a person about possible causes and developing a strategy towards getting better sleep. And, if you're interested more generally in what sleep is, and what some known sleep issues are, there's a nice current overview - free paper - called simply "Overview of sleep & sleep disorders."
Sleep Practice Feedback. In my group, we're doing research looking at the role awareness may play in wellbeing, health, quality of life. One of the devices we're using as a feed for the data is the Zeo. I've written about this before with a two part interview with Stephen Fabregas, sleep researcher, at Zeo. I'm also in the throes of prepping a review of using the device.
[EDIT - 2013: unfortunately the following kit is no longer available as zeo has closed down. THere are simple sleep monitors in commercial hardware like FitBit and Jawbone UP and also free actigarphy monitors on many phone platforms: these at least give an indication of time in bed/asleep and time restless. it's all about trends...]
Early summary: i really like it, and yes it's helped modify my behaviour to get better quality sleep. Why? because i can *see* it - my sleep cycles - i want to understand why i had less deep sleep or what's going on with low REM compared to how i usually sleep. What's different? Pretty simply it gives me a way to help make more grounded sense of how i'm doing. And it's making a difference.
There's also a sleep coach program that i'm just getting into, so that's why the review is not out yet - i want to see what that does, too. But even without the sleep coach, this device, compared with all the sleep info on the site, has been making a real difference to my perceived well being.
If you're interested, Zeo is offering a 10dollar off/free shipping deal with a coupon (here's the link). As said, i like it. I'm learning a lot. And am using it more than i do a heart rate monitor right now perhaps because this is such a new area of investigation for me.
Now, getting a zeo is not a replacement at all if one is suffering from excessive daytime sleepiness or related sleep issues in sitting down with a health pro to find out what may be going on with one's sleep - if there is some disease or drug or related Big Deal happening that requires attention. And sleep, as stephan said in the interviews, is SO crucial, and as the above research shows it's critical to get on top of it.What a zeo can do is reflect back, pretty clearly, if those strategies are working, and if so, how well. That wee display can also help keep us honest about our practice, and help us tune that practice. So it's no replacement for real counciling (nor is it designed to be) around a chronic issue, but it's a great way to help dial in and feedback the practice.
For instance, some of the quesitons i've had are: all things being equal, does timing of exercise in the evening REALLY effect my sleep quality? Does doing two split workouts a day do better than one? Can i really see any difference on fasting or better quality eating days? Very personal tuning to be sure, but it wasn't really possible to ask these quesitons previously as i had no real, clear way of correlating sleep with these practices. There's a section on the site "for health pros" that lists the research on this puppy.
Summary: Daytime sleepiness especially if it starts to become a pattern is NOT a good thing. It's associated with everything from poor mental health to, well, death. So, it's very much worth getting sleep quality up (and daytime sleepiness down). Sleepiness during the day, especially in older adults, seems to be a strong marker of a potential issue.
If general healthy sleep practices aren't working, checking in with a health professional like one's GP about what factors may be influencing it, and getting on top of it, are really important. It's awful to have health issues already where more will be amplified by poor sleep. A vicious cycle that needs to be broken. A sleep monitor tool in these cases to give good feedback on how well strategies, once they've been developed, are working.
Absolutely check with your GP; if you are not being physical yet, getting one with starting movement can be a HUGE boon. Here's an overview of getting some Time under Movement
If you are already moving and experiencing sleepiness, working with a qualified practitioner /coach who can look at your movement, nutrition, sleep and related is a Good Thing. I personally work with folks in consultation with their GP's assessments. They go great together.
But main takeaway: chronic daytime sleepiness - it's our bodies talking to us in a BIG WAY to say something needs to change. Seek help in figuring out what things to tune and how. You'll love how you feel.
begin2dig (b2d) on Facebook
Citations
Tweet Follow @begin2dig
Newman AB, Spiekerman CF, Enright P, Lefkowitz D, Manolio T, Reynolds CF, & Robbins J (2000). Daytime sleepiness predicts mortality and cardiovascular disease in older adults. The Cardiovascular Health Study Research Group. Journal of the American Geriatrics Society, 48 (2), 115-23 PMID: 10682939
Baldwin CM, Ervin AM, Mays MZ, Robbins J, Shafazand S, Walsleben J, & Weaver T (2010). Sleep disturbances, quality of life, and ethnicity: the Sleep Heart Health Study. Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine, 6 (2), 176-83 PMID: 20411696
Boulos MI, & Murray BJ (2010). Current evaluation and management of excessive daytime sleepiness. The Canadian journal of neurological sciences. Le journal canadien des sciences neurologiques, 37 (2), 167-76 PMID: 20437926
Chokroverty S (2010). Overview of sleep & sleep disorders. The Indian journal of medical research, 131, 126-40 PMID: 20308738
PDF
Tuesday, May 18, 2010
How Chefs think about Size - Portion Size that is (another b2d nugget)
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"Despite the focus on the increase in portion sizes and the possible role in the development of obesity, little is known about how portion sizes are determined in restaurants." This is how an intriguing discussion of Chefs and their restaurant food size practices begins. The study aslo notes that eating out has gone up from 2.3x's a week in 1981 to 5 times in 2000. Within that period we know that standard dinner plates have gone from 10 to 12 inch plates. So what do chefs - the folks in the restaurant it turns out who set portion size - think of as "regular" sizes?
Interestingly, chefs over 51 (trained in the smaller portion size era of the 70's) serve smaller sizes than younger chefs raised in the bigger portion period in which we find our super sized selves.
If you think that Chefs are in the know about nutrition when it comes to food prep, this may be a leap of faith. The authors write:
What Motivates Chef Portion Size Selection? Survey says, not surprisingly: "presentation of food", cost, customer expectations. Competition and calorie count had only "some influence." But intriguingly, competition with other restaurants was strongly correlated with portion size of say pasta and steak. What's wild (ok, to me) is that where "customer expectiation" was high, larger veggie side plates were served BUT when calories were perceived to be a biggie, that's when veggie portion sizes got SMALLER. That's rather an interesting insight for what chefs might be taught, no?
And indeed, from the text above on portion sizes, restaurants are serving larger than 2-3oz of veggies - when they serve veggies - and what's wrong with that? 1/2 a cup is nothing. Bring it on - as long as it's sans the oil, butter, deep frying and etc's. Have the condiments on the side and add as necessary. Or not. But that is a topic for another day.
Chef Perceptions: Here's something else interesting from the study: Chefs thought that patrons would notice if a serving size on their plate was 25% smaller - but a few things here: we are lousy at figuring size. And as we know from the last b2d post on energy density work, we can keep the plate looking just as full by using low energy dense foods, and folks can feel satisfied by same.
What does this lack of knowledge in the kitchen mean for eating out? Be not afraid to ask the kitchen to put together something for you closer to your spec, and your sizes, perhaps. Putting together a variety of sides (smaller by nature than their full meal counter parts) can often be great. If you're anything like me - if it's in front of you, you'll eat it (interesting related work showing i fear i'm not unique in this) - so an easier thing for me is just not to have the bigger size in front of me and say "serve it, i just won't eat all of it"
Are these findings a surprise? That chefs (600 surveyed; 80% response rate) seem not to understand that veggies are largely low cal foods, or that their portion sizes are so out of whack with any recommendations for such sizes? Or is it to be expected that chefs simply learn what tastes good and how to prepare it in an appetising way, with younger chefs going for bigger sizes?
Does this mean it is all the more surprising that it was a chef, Jamie Oliver, who noticed the appalling quality of "school dinners" in the UK & now the US? That if a chef noticed, they must be truly terrible?
But perhaps more than anything else, this kind of survey means: trust no one. WHile the study's authors want to investigate ways to help chefs get up to speed with nutrition relative to the food they prepare, in the meantime, we need to educate ourselves about what's healthy or not; an appropriate portion or not, and perhaps what seems is a particular challenge for some folks, to make specific requests of a restaurant when eating out, based on that knowledge.
External Resources:
CITATIONS
"Despite the focus on the increase in portion sizes and the possible role in the development of obesity, little is known about how portion sizes are determined in restaurants." This is how an intriguing discussion of Chefs and their restaurant food size practices begins. The study aslo notes that eating out has gone up from 2.3x's a week in 1981 to 5 times in 2000. Within that period we know that standard dinner plates have gone from 10 to 12 inch plates. So what do chefs - the folks in the restaurant it turns out who set portion size - think of as "regular" sizes?If you think that Chefs are in the know about nutrition when it comes to food prep, this may be a leap of faith. The authors write:
An unexpected finding of this study was that chefs who reported that calorie content was an important factor when determining portion size reported serving a smaller portion of a vegetable side-dish, such as steamed broccoli, compared with chefs who did not identify calorie content as being important. This suggests that chefs do not understand that such vegetables are low in energy density and can help customers moderate energy intake.So, as we saw in the last b2d post about energy density rather than portion size being a big factor in successful weight management AND meal satisfaction, there's a huge whack of chefs who are failing on both energy density and portion size.
Figure Above: When chefs were asked to describe their perceptions of the average portion size of foods served in their establishments (Figure 1), the majority (76% ) reported serving "regular" portions, and <20% reported serving "large" or "extra-large" portions. When respondents were asked to estimate the typical portion size of penne pasta served in their restaurant, 4 oz (27% ), 6 oz (32% ), and 8 oz (18% ) portions were most frequently reported, with 90% of respondents serving portions larger than United States Department of Agriculture's recommendation of 1 oz. For strip steak, 48% of the respondents indicated that 12 oz steaks were typically served in their establishment, and 28% reporting 8 oz portions as being typical, with 83% of respondents serving portions that were larger than the 5.5 oz that the government recommends should be consumed each day. Most respondents (38% ) reported serving 3-oz portions of a vegetable side-dish, with 31% reporting 4-oz portions. Forty percent of these respondents served vegetable portions larger than United States Department of Agriculture's recommendation of ½ cup (2 to 3 oz). When asked about the size of plates used in their restaurants, 38% reported using 9.25- to 11-inch plates, and 33% reported using 11.25- to 13-inch plates.
What Motivates Chef Portion Size Selection? Survey says, not surprisingly: "presentation of food", cost, customer expectations. Competition and calorie count had only "some influence." But intriguingly, competition with other restaurants was strongly correlated with portion size of say pasta and steak. What's wild (ok, to me) is that where "customer expectiation" was high, larger veggie side plates were served BUT when calories were perceived to be a biggie, that's when veggie portion sizes got SMALLER. That's rather an interesting insight for what chefs might be taught, no?
And indeed, from the text above on portion sizes, restaurants are serving larger than 2-3oz of veggies - when they serve veggies - and what's wrong with that? 1/2 a cup is nothing. Bring it on - as long as it's sans the oil, butter, deep frying and etc's. Have the condiments on the side and add as necessary. Or not. But that is a topic for another day.
Chef Perceptions: Here's something else interesting from the study: Chefs thought that patrons would notice if a serving size on their plate was 25% smaller - but a few things here: we are lousy at figuring size. And as we know from the last b2d post on energy density work, we can keep the plate looking just as full by using low energy dense foods, and folks can feel satisfied by same.What does this lack of knowledge in the kitchen mean for eating out? Be not afraid to ask the kitchen to put together something for you closer to your spec, and your sizes, perhaps. Putting together a variety of sides (smaller by nature than their full meal counter parts) can often be great. If you're anything like me - if it's in front of you, you'll eat it (interesting related work showing i fear i'm not unique in this) - so an easier thing for me is just not to have the bigger size in front of me and say "serve it, i just won't eat all of it"
Are these findings a surprise? That chefs (600 surveyed; 80% response rate) seem not to understand that veggies are largely low cal foods, or that their portion sizes are so out of whack with any recommendations for such sizes? Or is it to be expected that chefs simply learn what tastes good and how to prepare it in an appetising way, with younger chefs going for bigger sizes?
Does this mean it is all the more surprising that it was a chef, Jamie Oliver, who noticed the appalling quality of "school dinners" in the UK & now the US? That if a chef noticed, they must be truly terrible?
TED prize winner, Jamie Oliver, giving his TED talk
But perhaps more than anything else, this kind of survey means: trust no one. WHile the study's authors want to investigate ways to help chefs get up to speed with nutrition relative to the food they prepare, in the meantime, we need to educate ourselves about what's healthy or not; an appropriate portion or not, and perhaps what seems is a particular challenge for some folks, to make specific requests of a restaurant when eating out, based on that knowledge.
External Resources:
- Precision Nutrition - free overview about painless healthy eating heuristics
- Georgie Fear's "Dig In" cook book - healthy AND tasty.
CITATIONS
Condrasky, M., Ledikwe, J., Flood, J., & Rolls, B. (2007). Chefs’ Opinions of Restaurant Portion Sizes* Obesity, 15 (8), 2086-2094 DOI: 10.1038/oby.2007.248
Harnack, L., Steffen, L., Arnett, D., Gao, S., & Luepker, R. (2004). Accuracy of estimation of large food portions☆ Journal of the American Dietetic Association, 104 (5), 804-806 DOI: 10.1016/j.jada.2004.02.026
Wansink B, Painter JE, & North J (2005). Bottomless bowls: why visual cues of portion size may influence intake. Obesity research, 13 (1), 93-100 PMID: 15761167Tweet Follow @begin2dig
Sunday, May 16, 2010
b2d nugget: portion size is out; energy density is in for effective weight management
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You'd think with bigger sizes, folks would feel more full after a feeding than with smaller sizes. Apparently not so.
In 2005, researchers were interested in whether the increase in portion size at restaurants and in snack foods was contributing to the obesity epidemic. Rightfully they acknowledge that while that would SEEM to make sense, it's tough to say so conclusively.
So what they did look at was - does eating more make one feel more full (and so maybe eat less at any point?). They also looked at "energy density" - how many calories are packed into a food item with the same weight (broccoli low ed; ice cream, high) - to see if that had an effect on fullness.
Here's the simple takeaway: big pig portions don't leave one more satisfied. But we all know small portions can leave one feeling well hungry. So, solution? Help folks start to mix in low energy dense foods, and that's way more successful than asking them to cut the fat. Guess what? weight loss ensues as their energy uptake (amount of calories a day) goes down.
Here's the abstract
That last line says "eating satisfying portions" - which means that portions can still be pretty unfettered IF you're eating low energy density food. I wrote awhile ago how making mounds of greens super edible just by adding some really good balsamic vinegar. The beauty is, low energy density foods are also often HIGH in nutrient density. So, for instance, leafy greens are rich in macro and micronutrients while being low in kcals.
There's another related study in 2007 that shows however IF you can encourage folks to cut the fat a bit, after awhile, we don't miss it. So again another strategy towards saving kcals and weight management. Here's the abstract about how this finding was constucted:
That's cool. We happily adapt. SO of course someone had to look at the combination of some reduced fat and some engery density lowering foods together. Backlash? not at all. Good results:
The main thing in this last finding it seems is that again, we don't have to fiddle portion size on the plate particularly - which folks have a difficult time with as we looked at back when considering stupid set point theory - BUT get the mix of lowering fat and upping VOLUME of low energy dense food - which means good colours on the plate too, that we get to reduced caloric intake without feeling like we're starving.
Related resources:
Citations
You'd think with bigger sizes, folks would feel more full after a feeding than with smaller sizes. Apparently not so.In 2005, researchers were interested in whether the increase in portion size at restaurants and in snack foods was contributing to the obesity epidemic. Rightfully they acknowledge that while that would SEEM to make sense, it's tough to say so conclusively.
So what they did look at was - does eating more make one feel more full (and so maybe eat less at any point?). They also looked at "energy density" - how many calories are packed into a food item with the same weight (broccoli low ed; ice cream, high) - to see if that had an effect on fullness.
british nutrition foundation "feed yourself fuller" chart
Here's the simple takeaway: big pig portions don't leave one more satisfied. But we all know small portions can leave one feeling well hungry. So, solution? Help folks start to mix in low energy dense foods, and that's way more successful than asking them to cut the fat. Guess what? weight loss ensues as their energy uptake (amount of calories a day) goes down.
Here's the abstract
The increase in the prevalence of obesity has coincided with an increase in portion sizes of foods both inside and outside the home, suggesting that larger portions may play a role in the obesity epidemic. Although it will be difficult to establish a causal relationship between increasing portion size and obesity, data indicate that portion size does influence energy intake. Several well-controlled, laboratory-based studies have shown that providing older children and adults with larger food portions can lead to significant increases in energy intake. This effect has been demonstrated for snacks and a variety of single meals and shown to persist over a 2-d period. Despite increases in intake, individuals presented with large portions generally do not report or respond to increased levels of fullness, suggesting that hunger and satiety signals are ignored or overridden. One strategy to address the effect of portion size is decreasing the energy density (kilojoules per gram; kilocalories per gram) of foods. Several studies have demonstrated that eating low-energy-dense foods (such as fruits, vegetables, and soups) maintains satiety while reducing energy intake. In a clinical trial, advising individuals to eat portions of low-energy-dense foods was a more successful weight loss strategy than fat reduction coupled with restriction of portion sizes. Eating satisfying portions of low-energy-dense foods can help to enhance satiety and control hunger while restricting energy intake for weight management.
There's another related study in 2007 that shows however IF you can encourage folks to cut the fat a bit, after awhile, we don't miss it. So again another strategy towards saving kcals and weight management. Here's the abstract about how this finding was constucted:
This study establishes the reliability and validity of the Fat Preference Questionnaire©, a self-administered instrument to assess preference for dietary fat. Respondents select the food which tastes better and is eaten more frequently from 19 sets of food. Each set is comprised of related foods differing in fat content. The questionnaire was administered to women in laboratory-based (n=63), cross-sectional (n=150), and weight-loss (n=71) studies. The percentage of food sets in which high-fat foods were reported to “taste better” (TASTE score) and to be “eaten more often” (FREQ score) was determined. A measure of dietary fat restriction (DIFF) was created by subtracting TASTE from FREQ. Food intake was assessed by direct measure, 24-h recall, or food diary. Additionally, participants completed a standard survey assessing dietary restraint. Test–retest correlations were high (r=0.75–0.94). TASTE and FREQ scores were positively correlated with total fat intake (r=0.22–0.63). DIFF scores positively correlated with dietary restraint (r=0.39–0.52). Participants in the weight-loss trial experienced declines in fat consumption, TASTE and FREQ scores, and BMI values, and an increase in DIFF scores. Weight loss correlated with declines in FREQ (r=0.36) scores and increases in DIFF scores (r=−0.35). These data suggest that preference for dietary fat declines when following a reduced-fat diet and an increase in restraint for intake of dietary fat is important for weight loss. The Fat Preference Questionnaire© is a stable, easily-administered instrument that can be used in research and clinical settings.
That's cool. We happily adapt. SO of course someone had to look at the combination of some reduced fat and some engery density lowering foods together. Backlash? not at all. Good results:
BACKGROUND: Consuming foods low in energy density (kcal/g) decreases energy intake over several days, but the effectiveness of this strategy for weight loss has not been tested. OBJECTIVE: The effects on weight loss of 2 strategies for reducing the energy density of the diet were compared over 1 y. DESIGN: Obese women (n = 97) were randomly assigned to groups counseled either to reduce their fat intake (RF group) or to reduce their fat intake and increase their intake of water-rich foods, particularly fruit and vegetables (RF+FV group). No goals for energy or fat intake were assigned; the subjects were instructed to eat ad libitum amounts of food while following the principles of their diet. RESULTS: After 1 y, study completers (n = 71) in both groups had significant decreases in body weight (P < 0.0001). Subjects in the RF+FV group, however, had a significantly different pattern of weight loss (P = 0.002) than did subjects in the RF group. After 1 y, the RF+FV group lost 7.9 +/- 0.9 kg and the RF group lost 6.4 +/- 0.9 kg. Analysis of all randomly assigned subjects also showed a different pattern of weight loss between groups (P = 0.021). Diet records indicated that both groups had similar reductions in fat intake. The RF+FV group, however, had a lower dietary energy density than did the RF group (P = 0.019) as the result of consuming a greater weight of food (P = 0.025), especially fruit and vegetables (P = 0.037). The RF+FV group also reported less hunger (P = 0.003). CONCLUSION: Reducing dietary energy density, particularly by combining increased fruit and vegetable intakes with decreased fat intake, is an effective strategy for managing body weight while controlling hunger.
The main thing in this last finding it seems is that again, we don't have to fiddle portion size on the plate particularly - which folks have a difficult time with as we looked at back when considering stupid set point theory - BUT get the mix of lowering fat and upping VOLUME of low energy dense food - which means good colours on the plate too, that we get to reduced caloric intake without feeling like we're starving.
Related resources:
- b2d nutrition index
- respect the fat
- what's a "whole protein" - esp. going veggie
- set point theory is crap
- why is fish oil anti-inflamatory?
Citations
Ello-Martin JA, Ledikwe JH, & Rolls BJ (2005). The influence of food portion size and energy density on energy intake: implications for weight management. The American journal of clinical nutrition, 82 (1 Suppl) PMID: 16002828Tweet Follow @begin2dig
LEDIKWE, J., ELLOMARTIN, J., PELKMAN, C., BIRCH, L., MANNINO, M., & ROLLS, B. (2007). A reliable, valid questionnaire indicates that preference for dietary fat declines when following a reduced-fat diet Appetite, 49 (1), 74-83 DOI: 10.1016/j.appet.2006.12.001
Ello-Martin JA, Roe LS, Ledikwe JH, Beach AM, & Rolls BJ (2007). Dietary energy density in the treatment of obesity: a year-long trial comparing 2 weight-loss diets. The American journal of clinical nutrition, 85 (6), 1465-77 PMID: 17556681
Coming Up at b2d: satiety, embodied brains and movement makes us smarter?
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Hello Kind b2d Readers,
Been on the road for two weeks of non-stop work, so it's been a bit of a challenge to get content to the screen. And now i have a wee cold (keeping the grosser symptoms at bay with some chelated zinc), so as you know, that can kinda slow down the cognitive processes, too.
Coming Up at b2d: Just wanted to let you know, therefore, about some of the articles on the blocks for the near future:
Thanks for hanging in with b2d,
mc Tweet Follow @begin2dig
Been on the road for two weeks of non-stop work, so it's been a bit of a challenge to get content to the screen. And now i have a wee cold (keeping the grosser symptoms at bay with some chelated zinc), so as you know, that can kinda slow down the cognitive processes, too.
Coming Up at b2d: Just wanted to let you know, therefore, about some of the articles on the blocks for the near future:
- hunger as habit, and how that relates to what science seems to know about the markers around hunger like satiation and satiety; the role of energy density.
satiation is a big area of study - if we have great homeostatic mechanisms as an organism, why does weight get out of control? What are tested strategies to help get our eating back under control - to get the homeostatic to kick in to support hedonic change?
- the SAID principle - where'd it come from and what does it mean for training?
- And Related:
Is transferecnce (doing one activity in one domain that *seems* to contribute to another activity) a poor analogy for what's happening in sports training?
And in my increasingly fave area of the Embodied Brain (we're not just brains with bods attached)
- Exercise: competitive advantage
There seems to be an increasing amount of work that shows that exercise has a strong relationship to smarts. So, if our work requires us to be innovative, smart etc, not only staying healthy but fit - maybe it's mitochondrial processing that's pumping all that fresh o2 through the system - seems to mean a lot for a cognitive edge.
- Movement for Mental Function - related
there's some wild studies that show that when kids are let to gesture when doing long division, they do better at it then when they have to keep their hands still, they do less well. Our bodies help our brains do cognitive things. So why - i say SO WHY - are our office worker environments designed to be seated and still?
Thanks for hanging in with b2d,
mc Tweet Follow @begin2dig
Friday, May 7, 2010
Muscle Cramps in Calves when Running in Vibram FiveFingers: what is it, what causes it and what can be done about it?
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Runners Cramp - Calves cramping - it's AWFUL. In talking with folks who run in VFF's it seems that one usual side effect initially at least is that, when picking up the pace in VFF's (perhaps especially up hill), calves may start to cramp up. Guaranteed, if we keep going with this run, once that cramp starts, the calf or calves will turn to unyielding, painful rock. What can be surprising is how quickly into a run this seize up can happen. What the heck is going on, and what might help stop it from happening.
There could be lots going on, so i'm not trying to be comprehensive and exhaustive - not sure that's possible. The goal of this post is to look at pain generally, muscle cramps in particular and what's hypothesised about causes, introduce a newer model not seen in web discussions of cramp, and propose a refinement for that model. Finally, some practical suggestions of getting out of that cramp while heading to barefoot running freedom.
Pain is a signal for Change
Based on work in pain, and as summarized in work by David Butler like the plain language Explain 
Pain
, pain is a signal for change; pain does not necessarily, however, equal injury, and the site of pain is not always the source of pain; treating the site of pain therefore can be a losing proposition.
I've used the analogy of a car oil gauge regularly reading low. One solution is to top up the oil in the engine so that the gauge reads the right level. That level will only last short term and needs to be repeated regularly - and in the interim, what related problems might be developing from such regular loses?
Another solution is to do a diagnostic to find out what else might be going on - like a leak in the engine block where actually a bolt may simply need to be tightened (or an entire gasket in the block replaced - can you tell i'm having flashbacks of stripping the head of an engine in the middle of the bush on an old carola. never mind; i digress). The point is, getting away from site = source often leads to better results.
In the car analogy, finding a more fundamental issue, performing a wee tweak and testing if that tweak will work means that the oil level stays where it's supposed to be for as long as it's supposed to be there. Both approaches are a kind of solution; the benefits on the system and the wallet are better in the latter case.
What's a Cramp in the Calves Anyway?
So taking the above pain thesis into account, what does this mean for the calves rock effect?
What's a Cramp? A cramp is an involuntary and intense contraction of a muscle. What causes a cramp is a subject of much discussion, and poorly understood. A quick check on the web doesn't get at too much about why this contraction occurs.
WHy a cramp? The usual checks: electrolytes, hydration, low carbs, tight muscles to begin with are offered up not as reasons, but of things somehow thought to be related to cramping. Here's an examplary summary of that kind. In this model, the thesis seems to go, the muscles don't have the chemical materials needed to fire in that working limb properly so they effectively rigor mortis up. This rationale for cramp has been more or less tossed out as demonstrated here in 04, and as summarised in this recent BMJ review article. First, on dehydration:
Here's another view of cramps by Luke Hoffman that could be written for VFF runners:
The above describes what might be called "voluntary contraction" - not quite the same as involuntary. If we take the above council about voluntary cramps to bear, however, what should be the case is once a cramp starts, we should stretch it out, and wait for the fatigue to pass from that contraction, and recover, and really stop doing what we were doing - running on the forefoot. Consequently, Pose & VFF runners who run on the forefoot should be cramping all the time. And if we believe work in barefoot running, this is rather how we're designed to run. So, hmm, maybe not.
None of these explanations therefore is complete it seems, to explain cramping we see in the calves that comes on unexpectedly, as lots of well fed, well hydrtated, well electolyted people who stretch still get cramps, and these weird cramps in VFF's in particular.
So why does this cramp only happen *some* of the time - especially if all the typical niceities of cramp avoidance are observed? For me, for instance, it happened first when i started practicing actually bringing the heel of the foot down more (extending the calf) when running, rather than staying up on the forefoot. So, maybe it's not (entirely) about the calves?
Altered Neuromuscular Control. In the research one of the explanations around cramp is: maybe the muscle is just not strong enough to do what is being asked of it, for the duration it's being asked to operate at this level - hence fatiguing - and it's that fatigue that is setting up EAMC: exercise-associated muscle cramping. This hypothesis, also known as "altered neuromuscular control" was first proposed in 1996, so that's how new this stuff is. A key part of this model is that the neuromuscular control issue is located in the SPINE, not at the site of the issue - the site is paying for what's going on at the source.
So in the Pain as Signal to Change perspective, cramps are painful; they are a signal to change. The altered neuromuscular control model suggests, stretch it out and recover. Related work suggests, improve strength/stamina to reduce fatigue and reduce this muscle cramp response. Both have in common that fatigue is causing neural level loss of appropriate control.
Wildly Hypothesising? What's going on when this particular response occurs well before one would think a muscle used to running for miles and miles starts to go all crampy?
In
work pionered by LeDoux in the nineties
, he showed that the brain processes emotional responses like fear/threat without the conscious brain being involved. It happens fast, at a low level, without cognitive involvement and has immediate chemical consequences in the system (nice review of this and related work here by Ohman, 2005). In other words, perhaps there's some other *thing* happening in the sensory-motor exerperience that is saying "not good" and the result is this fatigue-like chemical messaging system that sets off early light cramp signals - that if ignored will just get louder until one is forced to change patterns.
In Z-Health, Eric Cobb translates this fear response into the nervous system's job to perceive threat or no threat: if there's a perception of threat, the system starts to shut down (example in arthrokinetic reflex). What might be the threat ocuring in VFF ocaisional calve cramping? The system may be literally putting on the breaks to what it perceives as a threatening to it's well being practice.
It's easy to see that if the nervous system perceives that the task - going at a particular speed in a particular way - is causing part of the system to be over-taxed, it's going to respond to that as a threat or non-optimal situation, and if it takes pain to get change, well, whatever it takes.
Personal Experience. Taking a Z-Health approach to this experience, i think i've learned to become more alert to any pain signal my bod sends up in an athletic effort. So in this case, if and when these cramps begin, they usually start with a very mild "uh oh" twinge of "about to turn to rock if you don't respond."
There are two simple things that z-health suggests for rehabbing a movement with the cue of "never move into pain:"
Guided by the Nose: run to pace inhalation. Another technique i've been using and coaching to help head off cramps and adapt to barefooting generally is to explore gaiting running speed with ability to stay breathing in through one's nose. If running at a clip where i have to mouth breath, i slow it down (i find if i hit that level, it's pretty hard to get it back to nose inhaling). This approach is just one way at least some of the time to practice running reps quality rather than overdriving the other parts of the system.
Deeper Tune Up: Starting from the Source
So we've seen one theory in the research is around muscular fatigue inducing EAMC; getting stronger in those areas where muscles cramped seemed to help. In one study. That's great. Another possibility - that can lead to faster fatigue - is if there's some kind of issue in one's movement that is causing perhaps other muscles to compensate for other weaknesses, and causing fatigue/pain/signaling in the calves faster that should happen for that group. So while a solution may be to do extra strength work, maybe a faster solution may actually be to look at one's movement as a whole.
In other words, the calves may be plenty strong IF everything else is firing up appropriately, but they may be being asked to super compenate for other stuff, that if those other movement issues were addressed, wouldn't cause the problem.
There's value therefore in (a) having a movement assessment and (b) practicing dynamic joint mobility and sensory-motor work to ensure great movement, and ability to maintain great, clean movement.
Summary: Avoiding Running Cramps in VFF's
Based on the latest research, EAMC cramps are about temporary loss of clear neuromuscular control. The best model so far to explain this effect is fatigue. A known way to work out a cramp is to lengthen the muscle. There may however be other approaches that just haven't been researched that also seem to work. The hypothesis here is that these approaches are dealing with neurological signaling, too, taking advantage of the sensory-motor system.
Some pragmatic responses therefore if cramp occurs are:
During a Run: Assuming one is not dehydrated, de-electrolyted, or have squirrels biting their calves while running,
And before That
Consider a movement assessment to check for what Gray Cook calls "weak links" so as not to build strength on top of dysfunction.
Let me know what works for you.
Citations
Tweet Follow @begin2dig
Runners Cramp - Calves cramping - it's AWFUL. In talking with folks who run in VFF's it seems that one usual side effect initially at least is that, when picking up the pace in VFF's (perhaps especially up hill), calves may start to cramp up. Guaranteed, if we keep going with this run, once that cramp starts, the calf or calves will turn to unyielding, painful rock. What can be surprising is how quickly into a run this seize up can happen. What the heck is going on, and what might help stop it from happening.
There could be lots going on, so i'm not trying to be comprehensive and exhaustive - not sure that's possible. The goal of this post is to look at pain generally, muscle cramps in particular and what's hypothesised about causes, introduce a newer model not seen in web discussions of cramp, and propose a refinement for that model. Finally, some practical suggestions of getting out of that cramp while heading to barefoot running freedom.
Pain is a signal for Change
Based on work in pain, and as summarized in work by David Butler like the plain language Explain Pain, pain is a signal for change; pain does not necessarily, however, equal injury, and the site of pain is not always the source of pain; treating the site of pain therefore can be a losing proposition.I've used the analogy of a car oil gauge regularly reading low. One solution is to top up the oil in the engine so that the gauge reads the right level. That level will only last short term and needs to be repeated regularly - and in the interim, what related problems might be developing from such regular loses?
Another solution is to do a diagnostic to find out what else might be going on - like a leak in the engine block where actually a bolt may simply need to be tightened (or an entire gasket in the block replaced - can you tell i'm having flashbacks of stripping the head of an engine in the middle of the bush on an old carola. never mind; i digress). The point is, getting away from site = source often leads to better results.
In the car analogy, finding a more fundamental issue, performing a wee tweak and testing if that tweak will work means that the oil level stays where it's supposed to be for as long as it's supposed to be there. Both approaches are a kind of solution; the benefits on the system and the wallet are better in the latter case.
What's a Cramp in the Calves Anyway?
What's a Cramp? A cramp is an involuntary and intense contraction of a muscle. What causes a cramp is a subject of much discussion, and poorly understood. A quick check on the web doesn't get at too much about why this contraction occurs.
WHy a cramp? The usual checks: electrolytes, hydration, low carbs, tight muscles to begin with are offered up not as reasons, but of things somehow thought to be related to cramping. Here's an examplary summary of that kind. In this model, the thesis seems to go, the muscles don't have the chemical materials needed to fire in that working limb properly so they effectively rigor mortis up. This rationale for cramp has been more or less tossed out as demonstrated here in 04, and as summarised in this recent BMJ review article. First, on dehydration:
A careful review of the literature did not identify a single published scientific study showing that athletes with acute EAMC are more dehydrated that control athletes (athletes of the same gender, competing in the same race with similar race finishing times). In contrast, there is evidence from four prospective cohort studies showing that dehydration is not associated with EAMC.And on electrolytes (and dehydration):
In summary, dehydration and electrolyte depletion are often considered together (and recently together with muscle fatigue) as the ‘‘triad’’ causing EAMC. The key components of this hypothesis (fig 1) are that electrolyte (mainly sodium) depletion through excessive sweat sodium loss together with dehydration causes EAMC. However, results from prospective cohort studies consistently show that athletes suffering from acute EAMC are not dehydrated, neither do they have disturbances in serum osmolality or serum electrolyte (notably sodium) concentrations. Furthermore, sweat sodium concentrations measured during exercise in 23 reported cases with a past history of EAMC are not higher than those reported in many other studies. Both electrolyte depletion and dehydration are systemic abnormalities, and therefore would result in systemic symptoms, as has been observed in other clinical conditions. However, in EAMC, the symptoms classically are local and are confined to the working muscle groups. Thus, the available evidence to date does not support the hypotheses that electrolyte depletion or dehydration cause EAMC — therefore an alternate hypothesis for the aetiology of EAMC has to be considered.And here's another typical "it's because you didn't stretch right" response - but you'll note the article doesn't raelly say *why* stretching prior to running does or does not do anything for cramp reduction. Indeed, when it comes to running and stretching, the current scene seems to suggest that a stretching program - not necessarily something done prior to running, but just putting this into one's routine - helps running mechanics. That's different. And has nothing to do with a pre-run routine to reduce cramps; as we'll see, stretching is used to respond to a cramp; not prep for one.
Here's another view of cramps by Luke Hoffman that could be written for VFF runners:
According to current theory in the sports science literature (as of 1997), skeletal muscle cramps during exercise probably happen when muscles that are shortened (for example, a calf muscle when your toe is pointed) are repeatedly stimulated. This can happen if your foot is extended, toe pointed, and you keep extending it further. You can actively do this by, for example, running on your toes or doing lots of toe-raises without going down to extend the muscle. What appears to happen is that the muscle gets fatigued, and it doesn't relax well. There is a reflex arc -- made up of the muscle, the nerves carrying signals to the central nervous system (CNS) and the nerves carrying signals from the CNS back to the muscle -- that keeps carrying contraction signals from and to the muscle. This appears to lead to a sustained contraction in the muscle, also known as a cramp.
Stretching (in this case, grabbing your toe and stretching the calf) is about the only thing that breaks this reflex arc signal and stops the cramp when it comes to exercise-induced cases. But the muscle is still fatigued, and the cramp process is easy to re-trigger until the muscle rests for a while. The fatigue-cramp process seems to happen most often in muscles that cross two joints, such as the calf muscle (which crosses the knee and ankle), since the muscle is easy to shorten and continue contracting.
The above describes what might be called "voluntary contraction" - not quite the same as involuntary. If we take the above council about voluntary cramps to bear, however, what should be the case is once a cramp starts, we should stretch it out, and wait for the fatigue to pass from that contraction, and recover, and really stop doing what we were doing - running on the forefoot. Consequently, Pose & VFF runners who run on the forefoot should be cramping all the time. And if we believe work in barefoot running, this is rather how we're designed to run. So, hmm, maybe not.
None of these explanations therefore is complete it seems, to explain cramping we see in the calves that comes on unexpectedly, as lots of well fed, well hydrtated, well electolyted people who stretch still get cramps, and these weird cramps in VFF's in particular.
So why does this cramp only happen *some* of the time - especially if all the typical niceities of cramp avoidance are observed? For me, for instance, it happened first when i started practicing actually bringing the heel of the foot down more (extending the calf) when running, rather than staying up on the forefoot. So, maybe it's not (entirely) about the calves?
Altered Neuromuscular Control. In the research one of the explanations around cramp is: maybe the muscle is just not strong enough to do what is being asked of it, for the duration it's being asked to operate at this level - hence fatiguing - and it's that fatigue that is setting up EAMC: exercise-associated muscle cramping. This hypothesis, also known as "altered neuromuscular control" was first proposed in 1996, so that's how new this stuff is. A key part of this model is that the neuromuscular control issue is located in the SPINE, not at the site of the issue - the site is paying for what's going on at the source.
There is a growing body of evidence to suggest that the mechanism for muscle cramping has a neuromuscular basis. Firstly, as has been discussed, voluntary muscle contraction or stimulation of the motor nerve can reliably cause muscle cramping. Secondly, there is evidence from experimental work in human subjects that stimulation of the 1a afferents through electrical stimulation or using the tendon tap (activating the 1a afferents) can induce cramping. Thirdly, it has repeatedly been shown that the most effective treatment for cramping induced in this manner is muscle stretching.
[WHY stretching?] An increase in tension in the Golgi tendon organ during stretching, which will result in increased afferent reflex inhibitory input to the a-motor neuron, is a plausible mechanism to explain why stretching is an effective treatment of cramping. [see Bertolasi and Co., '93]
[...]
There are other possible mechanisms that could alter neuromuscular control at the spinal cord level, and therefore may contribute to the development of EAMC. The first of these is the possibility that muscle injury or muscle damage, resulting from fatiguing exercise, could cause a reflex ‘‘spasm’’, and thereby result in a sustained involuntary contraction. The second possibility is that increased or decreased signals from other peripheral receptors (such as chemically sensitive intramuscular afferents, pressure receptors or pain receptors) could elicit a response from the central nervous system that can alter neuromuscular control of the muscles. These other mechanisms have not been investigated in athletes with EAMC, but would be important to explore in the future.
So in the Pain as Signal to Change perspective, cramps are painful; they are a signal to change. The altered neuromuscular control model suggests, stretch it out and recover. Related work suggests, improve strength/stamina to reduce fatigue and reduce this muscle cramp response. Both have in common that fatigue is causing neural level loss of appropriate control. Wildly Hypothesising? What's going on when this particular response occurs well before one would think a muscle used to running for miles and miles starts to go all crampy?
In
work pionered by LeDoux in the nineties, he showed that the brain processes emotional responses like fear/threat without the conscious brain being involved. It happens fast, at a low level, without cognitive involvement and has immediate chemical consequences in the system (nice review of this and related work here by Ohman, 2005). In other words, perhaps there's some other *thing* happening in the sensory-motor exerperience that is saying "not good" and the result is this fatigue-like chemical messaging system that sets off early light cramp signals - that if ignored will just get louder until one is forced to change patterns. In Z-Health, Eric Cobb translates this fear response into the nervous system's job to perceive threat or no threat: if there's a perception of threat, the system starts to shut down (example in arthrokinetic reflex). What might be the threat ocuring in VFF ocaisional calve cramping? The system may be literally putting on the breaks to what it perceives as a threatening to it's well being practice.
It's easy to see that if the nervous system perceives that the task - going at a particular speed in a particular way - is causing part of the system to be over-taxed, it's going to respond to that as a threat or non-optimal situation, and if it takes pain to get change, well, whatever it takes.
Personal Experience. Taking a Z-Health approach to this experience, i think i've learned to become more alert to any pain signal my bod sends up in an athletic effort. So in this case, if and when these cramps begin, they usually start with a very mild "uh oh" twinge of "about to turn to rock if you don't respond."
There are two simple things that z-health suggests for rehabbing a movement with the cue of "never move into pain:"
- reduce the range of motion
- reduce the load
Guided by the Nose: run to pace inhalation. Another technique i've been using and coaching to help head off cramps and adapt to barefooting generally is to explore gaiting running speed with ability to stay breathing in through one's nose. If running at a clip where i have to mouth breath, i slow it down (i find if i hit that level, it's pretty hard to get it back to nose inhaling). This approach is just one way at least some of the time to practice running reps quality rather than overdriving the other parts of the system.
Deeper Tune Up: Starting from the Source
So we've seen one theory in the research is around muscular fatigue inducing EAMC; getting stronger in those areas where muscles cramped seemed to help. In one study. That's great. Another possibility - that can lead to faster fatigue - is if there's some kind of issue in one's movement that is causing perhaps other muscles to compensate for other weaknesses, and causing fatigue/pain/signaling in the calves faster that should happen for that group. So while a solution may be to do extra strength work, maybe a faster solution may actually be to look at one's movement as a whole.
In other words, the calves may be plenty strong IF everything else is firing up appropriately, but they may be being asked to super compenate for other stuff, that if those other movement issues were addressed, wouldn't cause the problem.
There's value therefore in (a) having a movement assessment and (b) practicing dynamic joint mobility and sensory-motor work to ensure great movement, and ability to maintain great, clean movement.
Summary: Avoiding Running Cramps in VFF's
Based on the latest research, EAMC cramps are about temporary loss of clear neuromuscular control. The best model so far to explain this effect is fatigue. A known way to work out a cramp is to lengthen the muscle. There may however be other approaches that just haven't been researched that also seem to work. The hypothesis here is that these approaches are dealing with neurological signaling, too, taking advantage of the sensory-motor system.
Some pragmatic responses therefore if cramp occurs are:
During a Run: Assuming one is not dehydrated, de-electrolyted, or have squirrels biting their calves while running,
- As soon as a cramp (pain) starts, change something - gait, speed, whatever; if that doesn't work, stop what you're doing.
- consider rather than (just) stretching, doing mobility/sensory-motor work.
And before That
Consider a movement assessment to check for what Gray Cook calls "weak links" so as not to build strength on top of dysfunction.
Let me know what works for you.
Citations
Schwellnus, M. (2008). Cause of Exercise Associated Muscle Cramps (EAMC) -- altered neuromuscular control, dehydration or electrolyte depletion? British Journal of Sports Medicine, 43 (6), 401-408 DOI: 10.1136/bjsm.2008.050401
OHMAN, A. (2005). The role of the amygdala in human fear: Automatic detection of threat Psychoneuroendocrinology, 30 (10), 953-958 DOI: 10.1016/j.psyneuen.2005.03.019
Bertolasi L, De Grandis D, Bongiovanni LG, Zanette GP, & Gasperini M (1993). The influence of muscular lengthening on cramps. Annals of neurology, 33 (2), 176-80 PMID: 8434879
Wagner, T. (2009). Strengthening and Neuromuscular Reeducation of the Gluteus Maximus in a Triathlete With Exercise-Associated Cramping of the Hamstrings Journal of Orthopaedic and Sports Physical Therapy DOI: 10.2519/jospt.2010.3110
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