Thursday, January 21, 2010

Fasting and Workouts: does it work out?

ResearchBlogging.orgThere is growing interest in intermittent fasting and athletic performance - or how can i train if i'm not eating? In the past year there have been a couple of cool studies looking at athletic performance and the effects of the Ramdam fast on same. The Ramadan fast is, to the best of my knowledge, a total break in eating for part of a day: from sun up to sun down, no food. Since this is the time of day most athletes train, one might think going without food would make training impossible, or that athletes would start to cave in competition against their opponents.

So no kidding this particular combo of IF and Sport has been studied a LOT - just put ramadam and exercise into Pubmed, and you'll see.

There was a large study, however, carried out in 2006 and reported on in 2008. The study involved three teams that lived in residence at the training ground. The abstract is so complete, rather than paraphrase, let me present it here.

J Sports Sci. 2008 Dec;26 Suppl 3:S3-6.
Influence of Ramadan fasting on physiological and performance variables in football players: summary of the F-MARC 2006 Ramadan fasting study.

Zerguini Y, Dvorak J, Maughan RJ, Leiper JB, Bartagi Z, Kirkendall DT, Al-Riyami M, Junge A.
Centre d'Evaluation et d'Expertise en Medecine du Sport, Algiers, Algeria.

The timing of food and liquid intake depends on the times of sunset and sunrise during the month of Ramadan. The current body of knowledge presents contradicting results as to the effect of Ramadan fasting on body mass, body composition and metabolic changes. The main objective of the present investigation was to gain additional information and scientific data in conformity with the philosophical background of Islam to allow optimisation of the daily training and dietary regimen in relation to the mental and physical performance of football players. The four teams, along with their coaches and trainers, attended a residential training camp at training centre 3 weeks before the start of Ramadan and throughout the study. Energy intake was relatively stable in the fasting group, but there was a small, albeit significant, decrease of approximately 0.7 kg in body mass. Water intake increased on average by 1.3 l/day in line with the greater energy intake in the non-fasting group in Ramadan. Daily sodium intake fell during Ramadan in the fasting players but increased slightly in the non-fasting group. Fasting players trained on average 11 h after their last food and drink, and reported that they felt slightly less ready to train during the Ramadan fast. None of the assessed performance variables was negatively affected by fasting while nearly all variables showed significant improvement at the third test session, indicating a training effect. Heart rate measurements in one training session during the third week of Ramadan appeared to suggest that the training load during training was marginally greater for the fasting than for the non-fasting players. However, the overall exercise load measures indicated that there was no biologically significant difference between the fasting and non-fasting groups. In the present study, biochemical, nutritional, subjective well-being and performance variables were not adversely affected in young male football players who followed Ramadan fasting in a controlled training camp environment. Physical performance generally improved, but match performance was not measured. We recommend that players should ensure adequate sleep and good nutrition during Ramadan to preserve football performance and general health.
SO, pretty much doing a ramadam style sunrise to sunset fast doesn't negatively impact pretty durn intense competitive training.

What this and other studies have noted, however, and you can see it in the recommendation of the last line - is that athletes' biggest issue was their perception of sleep quality - feeling like the had about an hour less a night than when they weren't fasting. One other report was that, even though the actual performance measures were not impacted, they did subjectively feel less ready to train than when they weren't fasting. Training was about an 11h day, by the way.

CAVEAT: I have to note that the funding for the study was provided by FIFA, and it makes sense that it would be in their interests to find that religious observance did not interfere with physical/professional requirements. On the other hand, they might be just as keen to know if there was a problem with their highly paid athletes not being able to perform optimally.

So what's a geek to do? Look for more evidence. A 2009 review of the literature on athletes and Ramadam seems to concur with the above outcomes being repeated in other studies, and so it asks a new question: what the heck is going on to let athletes perform well under these conditions?

Int J Sports Physiol Perform. 2009 Dec;4(4):419-34.
Effects of ramadan intermittent fasting on sports performance and training: a review.

Chaouachi A, Leiper JB, Souissi N, Coutts AJ, Chamari K.

Research Unit "Evaluation, Sport, Health," National Centre of Medicine and Science in Sport, Tunis, Tunisia.

The month-long diurnal Ramadan fast imposes a major challenge to Islamic athletes. Sporting events are programmed throughout the year, with the result that training and competition are often scheduled during Ramadan. The small numbers of well-controlled studies that have examined the effects of Ramadan on athletic performance suggest that few aspects of physical fitness are negatively affected, and only modest decrements are observed. Whereas subjective feelings of fatigue and other mood indicators are often cited as implying additional stress on the athlete throughout Ramadan, most studies show these measures may not be reflected in decreases in performance. The development and early implementation of sensible eating and sleeping strategies can greatly alleviate the disruptions to training and competitiveness, thus allowing the athlete to perform at a high level while undertaking the religious intermittent fast. Nevertheless, further research is required to understand the mechanisms and energy pathways that allow athletes to maintain their performance capacities during Ramadan, and which factors are responsible for the observed decrements in performance of some individuals.
That's cool when a summative paper actually says ok, based on this what are the cool questions to look at, and there are at least two: (a) what's happening physiologically to allow this kind of performance, despite less than optimal feelings about it and (b) how come this doesn't seem to work for some people - some people's performance does go down. Why/how are they different?

Take Away: In the context of a 30 day, summer daylight fast (long days; shorter nights) as Ramadan is at least for people practicing it in Tunisia, it is possible to fast during that time, when eating and resting appropriately on either side of the fast to support athletic training consisting mainly of endurance style effort for football.

This approach to eating for training at very limited times raises interesting questions about nutrient timing. We also don't know what would happen if this approach to training were carried on longer than a month.

Indeed, in the fifa funded study (the first one, above) there's a reported satelite study that showed that after the fast, in the two weeks of follow up, the post-fasting team members' endurance went up.

While this finding is different than the approach in Intermittent Fastingof work like Eat Stop Eat (24hour long fasts, max) that says it's ok to fast and resistance train in a fasted state; there's no muscle loss as long as resistance work is kept up, can we say categorically that fasting and training go well together? There's a seemingly obvious kind of correlation that says, at least for brief periods - whether 24 hours of no eating, or 30 days of daylight limited eating - we can handle training in a fasted state.

Whether this is optimal or not is not clear, but it seems to be at least ok.

Related Posts

Zerguini Y, Dvorak J, Maughan RJ, Leiper JB, Bartagi Z, Kirkendall DT, Al-Riyami M, & Junge A (2008). Influence of Ramadan fasting on physiological and performance variables in football players: summary of the F-MARC 2006 Ramadan fasting study. Journal of sports sciences, 26 Suppl 3 PMID: 19085447

Chaouachi A, Leiper JB, Souissi N, Coutts AJ, & Chamari K (2009). Effects of Ramadan intermittent fasting on sports performance and training: a review. International journal of sports physiology and performance, 4 (4), 419-34 PMID: 20029094


Chris said...

A good post mc

Here is another relevant study

mc said...

Thanks Chris.

The study is very precision nutirition in terms of initially, carbs only after workouts, when known to be useful.

The caveat is that that's default until a person gets a handle on their own carb tolerance.

Some folks handle pre-workout carbs and their weight just fine. So i just ain't much into absolute positions.

Even here, while fasting during daylight was ok for most, it wasn't ok for all. hmmm.

Chris said...

I agree - everyone is different. However there are maybe as you say some basic positions from which people could experiment.

mc said...

Yes chris, agreed on basic positions. again, that's a very precision nutrition response on your part:

the baseline with respect to starchy carbs is not to have them until after a work out when they are known to be of particular value to the muscles.

If you're curious to overlook the other starting points with pn, they're in a free ebook here.


Roland Fisher said...

I love PN, heck I'm on their staff as a lean eating coach. I also IF.

My experience is that when we challenge our dogma we get better results. PN isn't a diet plan, it is a science based system weighing heavily on a behavioural approach to getting results. As such, PN has room for IF. Granted it is after we master the basics though, that individualization occurs.

Thanks for the write up mc, good hamster prodding info there.

Mike T Nelson said...

Thanks for the data here MC on intermittent fasting.

For most, once accustomed to it, it can be a valid option.

As mentioned above, the individual results are what is most important.

There are also data showing that the use of carbs during long duration exercise to be beneficial (ergogenic).

I also think that intermittent fasting should increase an athlete's metabolic flexibility by providing a period of time of mostly using fat as fuel.

Rock on
Mike T Nelson
Extreme Human Performance

mc said...

Rolan, thanks for the feedback. You're one of those interesting PN/ESE hybrids, and i appreciate the feedback.

wow, that is a totally cool angle in terms of metflex. awesome idea.

It's kind of interesting that if the caloric loads are the same - as the studies say they are - but they're just timed differently - and we see that the FM goes down (i'll have to check the numbers) in the fasting group, that would seem to indicate an interesting thing: despite even calories across both groups, the fasting group is burning more fat during the day that isn't getting replaced in the meals pre/post.

how does that happen?



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