Thursday, May 27, 2010

Fasted Training Boosts Endurance and Muscle Glycogen

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In this article I wrote about a study that showed an anabolic rebound effect during feeding after fasted weight training. The title of that article ended with a question mark, since it was a (very) short-term study with results that were far from conclusive in regards to fasted training being superior to fed state training.

However, when it comes to endurance training, there's compelling evidence showing that fasted state training is superior, or complementary, to fed state training.

Now, for those of you that have no interest in endurance training, bear with me. At the end of this article I will tell you how fasted state weight training may provide additional benefits, not discussed before, based on some new findings.


Fasted endurance training

One idea that has been tossed around in the endurance training community is that training sessions should be performed in the least performance-enhancing situation to ensure the most potent training stimulus. Training fasted, or under conditions with low muscle glycogen, could be superior to fed state training when it comes to inducing the fastest adaptations to training.

Two fairly recent studies has lent credence to this notion (De Bock and Nybo). While the researchers didn't find any significant differences in some of the measured variables, it's interesting to note that the fasted-trained groups in both studies showed higher levels of resting muscle glycogen concentrations after training. Similar to the anabolic rebound for fasted weight training, there seems to be an anabolic rebound during feeding after fasted endurance training through more efficient glycogen storage.

Looking at real world examples, the Kenyans, hailed for their superior endurance in running events, are known for doing a brunt of their training in the fasted state. They also follow a high carb diet to maximize muscle glycogen storage. According to experts, this pattern of "training low" and "competing high" might provide a distinct advantage. Muscles that are well stocked with glycogen can simply outwork the competition.



Back in Cape Town, during my modelling days, I did my fair share of endurance training. The scenery was amazing. It was hard not to take advantage of it. I became known as the go-to-guy for sports and ended up doing a lot of work for various sportswear brands. The picture is from a Swedish sportswear chain called Stadium.


The new study

Results of a new study on fasted endurance training was released just a few weeks ago. The primary aim here was to test the hypothesis that fasted state endurance training would yield greater improvements in fuel utilization and boost muscle glycogen storage efficiency. A hypothesis that was based on results seen in prior studies on this topic. The secondary aim was to see if the effects differed between genders, since men and women favor slightly different fuels during exercise. Men tend to utilize more glucose, while women tend to burn more fat.

This study lasted four weeks and had all subjects cycling 25 minutes at 65% VO2Max five mornings the first week. The duration was then increased by 25 minutes per week, so that subjects were cycling 100 minutes in the final week.

The cycling was either done in the fasted state or one hour after a cereal-based breakfast (1.5 g carbs/kg). In weeks three and four the fed group also received 30 g of maltodextrin during training. The fasted group received the breakfast, and the maltodextrin, after training.

Week 1, fasted: 25 min cycling followed by breakfast.
Week 2, fed: breakfast followed by 25 min cycling.

Week 4, fasted: 100 min cycling followed by breakfast and maltodextrin.
Week 4, fed: breakfast followed by 100 min cycling and maltodextrin.

With regards to the diet maintained outside the laboratory, weighed food records was collected to ensure that potential differences could not be explained by differences in diet. This was done pre-training and in the final week. The findings showed that calorie intake increased in both groups, with an increase coming mainly from carbs and protein. But no difference in total calorie intake or macronutrient intake existed between groups.


The results

After the study, the researchers summed up the improvements in a few relevant variables related to performance, muscle glycogen and fuel utilization. I'll give you a brief rundown of what each of these variables means before showing the changes in the fasted and fed groups.

VO2Max: "The highest rate of oxygen consumption attainable during maximal or exhaustive exercise" (Wilmore & Costill, 2007). This is a rough measure of fitness.

Both groups started out with levels around 3.5 liters per minute (l/min), which is close to standards for untrained individuals. To put this into perspective, elite endurance athletes have about twice that capacity. One Norwegian skier topped this chart at 7.3 l/min. A more accurate measure of VO2Max is ml/min/kg, but in this study l/min was noted.

Fasted: +9.7% increase
Fed: +2.5% increase

The fasted group increased their VO2Max significantly more than the fed group. Interesting.

It's also noted that "Whilst peak power increased in both groups, there was a strong tendency for FAST to improve their peak power more than FED".

Muscle glycogen content: This is measured in millimoles per kilo dry muscle and shows how much glucose is stored in the muscle. The sample was taken from vastus lateralis, a portion of the quads, since this was the main muscle exercised during the cycling sessions.

Fasted: +54.7% increase
Fed: +2.9% increase

As you can see, the fasted group showed a dramatic increase in muscle glycogen content compared to the fed group. It's almost too good to be true.

Citrate synthase (CS): This enzyme is critical for the initiation of the citric acid cycle, which regulates the mobilization of fat and converts glycogen into glucose for use during exercise. Think of it as a marker for fuel utilization efficiency.

Fasted: +17.9% increase
Fed: +19.1% increase

While the differences between groups, on average, did not show any significant differences, these appeared when comparing the results obtained from the women with those of the men. When this comparison was made, fasted training was found to stimulate significantly greater increases in CS in men (+35%) than in women (+10%).

On the other hand, fed training stimulated significantly greater increases in women (+25%) than men (+10%).

Men attained a more much better response from fasted training, while women received a more favorable response from fed training.

3-hydroxy-CoA dehydrogenase (HAD): Also a marker for fuel utilization efficiency, but this one is specifically involved in fatty acid metabolism. Think of it as a fat burning enzyme.

Fasted: +3.5% increase
Fed: +9.1% increase

As was the case with CS, the mean increase above is a bit misleading, since there were big differences in between fasted and fed groups depending on gender.

When looking at gender differences, females showed a stronger response than males (+5% fasted and +25% fed). This goes in line with prior studies which show that the HAD activity of female muscle is more responsive to the same training stimulus. Males in both groups showed only subtle change that was deemed non-significant (+3% fasted and -10% fed). However, fasted training seems to provide a slight edge once again.

Summary

Quoting straight from the discussion in the full text paper:

"The main findings of the present study were that: training in an overnight-fasted state enhances storage of muscle glycogen compared to training in the fed state; skeletal muscle of men and women respond differently in terms of oxidative activity to training in the fed and overnight-fasted state; and peak VO2 and peak power improved more when training in the fasted state compared to the fed state."

Questioning the dramatic increase (+54.7%) in muscle glycogen in the fasted group, the researchers were not able to find an answer based on unexpected confounders or behaviors between groups. Muscle biopsies were taken at the same time and there were no difference in diet in between groups.

"...it is highly likely that the differences in glycogen stores between groups reflect the training intervention and not exercise timing or pre-biopsy diet."

Moreover, these results are in line with a prior study that found similar results for fasted training.

"Importantly, our findings correspond to that of De Bock et al. confirming that training whilst circulating CHO levels are low increases the capacity to accrue glycogen in the trained muscles."

What might be the reason for the different effects between genders on oxidative enzymes? As mentioned previously, differences in fuel utilization. Males rely less on intramuscular triglycerides and fatty acids and more on glucose, while females burn a higher percentage of fat at any given exercise intensity. But why fed state training would then be more beneficial for females when it comes to "oxidative adaptation" requires further investigation.


My thoughts

This study is great news for anyone doing fasted training, particularly the kind that involves elements of conditioning and glycogen depletion such as CrossFit, kettlebell training, PX90. Or just about any kind of endurance training. Based on feedback from readers and clients, it reflects my personal experiences in this area as well (performance enhancing effects of fasted state training with little or no dietary intervention).

I would expect the effects seen here to be similar for weight training, just of a much lesser magnitude. Traditional weight training doesn't improve VO2Max nearly as much as the aforementioned activities, nor is it as glycogen intensive* - but still, boosting your ability to soak up carbs as glycogen should have benefits for nutrient partitioning and performance. Not to mention the ability to eat more carbs without triggering de novo lipogenesis (the conversion of glucose into fat).

* Some numbers: For an average weight male, 25 mins cycling at 65% VO2Max expends roughly 250 kcal. At 65% VO2Max, fuel utilization is half glucose and half fatty acids, so each session depleted about 30 g glycogen in week 1 and 120 g glycogen in week 4. Rough numbers for weight training is 2.5 g glycogen per set of 10 reps at 70-75% 1RM. 25 mins of cycling is approximately the equivalent to a weight training session of 10-12 sets in terms of glycogen depletion (not counting excess post-exercise oxygen consumption which is small, but a tad higher for weight training).

It would be interesting to see whether competing bodybuilders, for whom size matters more than strength, could benefit from some higher volume weight training in the fasted state. On a cyclic diet, where higher carbs are consumed on training days, the improved ability to store carbs as glycogen will give the appearance of fuller and larger muscles - a clear advantage on the stage.

It would also be interesting to see whether such a protocol, fasted state high volume weight training, would provide benefits in regards to hypertrophy*. One theory that has been floating around is that of the anabolic effects of glycogen supercompensation. The Ultimate Diet 2.0, based around low carbs and concomittant glycogen depletion with a supercompensation phase, is designed partly around this concept.

* However, while this is an interesting thought, I still don't think glycogen depletion should play an important part in the natural weight trainer's lifting regimen. I consider it arguably more important to focus on progressive overload in the 4-8 rep range first and foremost. That being said, I have experimented with a few higher rep back-off sets (to induce modest glycogen depletion) following the heavier sets with good results. But I digress. Let's get back on topic.


Mechanisms


By what mechanism does fasted training lead to fuller muscle glycogen stores? I think the effects seen here might be explained by an increase in glycogen synthase, which is an enzyme involved in converting glucose to glycogen. Endurance training increase glycogen synthase, as would I expect any other form of activity that draws upon glycogen stores. On top of that, studies on intermittent fasting show a similar effect via phosphorylation of glycogen synthase kinase. Training in the fasted state might provide a synergistic effect, or at least be a double whammy, since both short term fasting and training independently induces adaptations that favors glycogen replenishment.

And what might explain the greater improvements seen in VO2Max? On that topic, I have no clear cut explanation, nor do the researchers in this study. If anyone is well versed in the scientific literature on endurance training, feel free to chime in and speculate.


Interrupting the homoestatic machinery


To explain these results in a broader framework, it might be fruitful to think of the fasted state as an additional stressor, on top of the training itself, that interrupts the homeostatic machinery of the body to a greater extent than that of fed state training. Greater interruption means greater adaptation in the recovery phase.

A similar pattern can be seen in some other phenomena. In my article on fasted training and muscle growth I mentioned that "studies show that ingesting antioxidants from supplements weakens the body's own response to deal with free radicals created by training. "

My point here being that if you make it too easy for the body to adapt, it won't see a need to adapt, or the adaptation might not be as powerful. Force it to adaptation while training under more strenuous conditions and you will reap the benefits. This is what this study shows and what the study on fasted training and muscle growth hints at.


Coming up

While there seems to be some clear benefits of fasted cardio in terms of improving endurance and muscle glycogen storage, this form of training may hamper muscle growth by a few different mechanisms. Besides being potentially catabolic to muscle growth by accelerating de novo gluconeogenesis (the conversion of amino acids to glucose), it may also interfere with cellular adaptations to weight training.

Someone interested in preserving or gaining muscle while using cardio for improving conditioning, or as means to speed up fat loss, need to be cautious and implement strategies to sidestep the negative effects. This will be the topic of the next article on fasted state cardio (ETA: Sept).

74 comments:

Frankie said...

I had the pleasure of working with one of the authors on that paper.

Unfortunately Johann Edge was recently killed by a car while he was out riding in Auckland, leaving behind a wife and three young children.

He was a nice guy

http://www.ses.auckland.ac.nz/uoa/science/about/departments/ses/news-events/ses_news.cfm

Chino said...

Great post Martin, informative as always. I got pretty cut up on a CKD/SKD phase where I would always do cardio work on a fasted state. Muscle loss were minimal and I think that regular work of moving iron around as well as consuming enough protein helped, as well as being in a state of ketosis. On top of that, energy levels were higher, surprisingly despite being on a daily deficit of about 20% to 25%.

LayzieBone085 said...

Another nail in the coffin against broscience!
Would love to see how this would play out with the addition of BCAA's during the fasted training and if there would be any response in Post-Workout protein synthesis or an increase protein turnover to post-workout (focus on lifting / bodybuilding) I bet the BCAA's would aid the endurance performance especially if your workouts are glycogen depleted focused.

Tom said...

Great stuff Martin. Very interesting.

Manveet said...

great stuff. Very informative. Looking forward to the next piece.

Clint said...

Great stuff mate. I used the train low/high method back when I was dabbling in long distance running and it definitely improved my times. I'm just a happy amateur though so no big comps or anything of that sort.

Eric Komans said...

I love this blog. It keeps me thinking about my training in constructive ways when I otherwise might flounder around with different "you should" training principles.

I definitely saw the connection with UD2's cycling. That was my first really-regimented, scientifically-based approach to dieting and training so I almost nostalgically relate things to it. Was cool to see you acknowledge a link there.

Keep up the good work. It is appreciated.

Bob said...

Thanks for that. I am interested in this kind of stuff as a rower due to the power/endurance component involved in training. Certainly 20km at 18 strokes per minute is endurace.

Fredrik Gyllensten said...

Really great article Martin, very interesting!

FN said...

Great info Martin! Haven't you had time to answer your client requests or have you missed mine? I figure your time-schedule is pretty hectic.

I sent mine on the 10th of May, hope to hear from you!

Jake said...

GREAT post Martin ... and very good news for me! I have been taking part in fasted morning training for almost 10 years now, and I've always felt great doing so. I eat a fairly high protein/carb meal shortly after my weight workouts which tends to be very satisfying. On cardio days I also train fasted, however I typically do not eat immediately afterwards, but wait for a few hours (with the hope of burning more fat). It has always amazed me that I actually feel stronger during fasted cardio than fed cardio.

Anyway, thanks as always for another great post ... out of curiousity, will information like this make it in your book, or is it too late? Keep the info coming ... this is an outstanding site/blog for fitness-minded individuals!

Martin Berkhan said...

Thanks guys.

Frankie,

That's very unfortunate to hear :( He was involved in many interesting studies in the last year.

Jake,

Yes, there will be similar stuff in the book.

John Salvig said...

Great article, Martin. I e-mailed you ~2 weeks ago regarding a consultation. Did you receive my e-mail or are you too overloaded at the moment?

Martin Berkhan said...

FN & John,

I will get back to you soon.

John Nakamura said...

Fascinating information and excellent content, Martin!

I have forwarded this to a few of my cycling buddies:)

Btw, your writing is very good. Hard to believe that english is not your first language.

Keep up the great work!

Anonymous said...

Thanks for this great post.

My Low Carb Road to Better Health said...

I notice that you are recommending "Eat Stop Eat" on your blog. I looked at their website, and it says that you can eat anything you want, like pizza, cookies, cake, sugar, as long as you IF. What are your thoughts on this? Thanks! Rebecca

John said...

Am I correctly assuming that if I have a substantial carb based meal right before going to bed and engaged in high intensity - low volume early morning fasted training, then there would be little to no danger of muscle catabolism?

Anonymous said...

"Someone interested in preserving or gaining muscle while using cardio for improving conditioning, or as means to speed up fat loss, need to be cautious and implement strategies to sidestep the negative effects. This will be the topic of the next article on fasted state cardio."

Can't wait for that article. As someone who is trying body recomposition and trains grappling, info on this would be much helpful. To take BCAA before fasted cardio or not? To take caffeine to mobilize fat or not? A lot of questions, so many conflicting answers on the web.

Waiting for you Martin to shed some light. Thx in advance.

Martin Berkhan said...

Rebecca,

I can't speak for Brad's marketing, but I don't recall it actually saying that in the book. What I think Brad is implying is that you could eat those foods in moderation and not that they should be regular dietary staples.

John,

Read this post:

http://leangains.blogspot.com/2010/05/early-morning-fasted-training.html

or the Fasted Training protocol in the Leangains Guide. You should have some aminos in your system around workout time. You still will, if your last meal of the prior day is substantial and high in protein, but this is a case where it's better to be safe than sorry.

My Low Carb Road to Better Health said...

Thanks for answering, Martin! When I spoke of the cookies, etc., I was referring to the testimonials given as part of his presentation about what the book was about. He would tell a little bit in his own words, then give a quote from a follower, and they would say things about eating whatever they want, like cookies, cake, pizza, etc. So I naturally assumed that the book allowed for that kind of eating on a regular basis.

Martin Berkhan said...

I don't think any successful diet would include those foods on a regular basis. Then again, it depends on what your definition of regular is. One, twice or even three times a week won't kill your progress if moderation is exercised. Problem is a lot of people won't stop at just one slice of pizza or cake.

Martin Berkhan said...

Hell, look at me. I won't stop at one piece of cheesecake.

http://leangains.blogspot.com/search/label/Cheesecake%20Mastery

I'll eat the whole thing. But I don't do that on a regular basis and I'll lower calorie intake the next 2-3 days to get the water weight off.

The key point here is balance.

My Low Carb Road to Better Health said...

Yeah, I kinda noticed that the other day! LOL!

What the heck was THAT all about??? Was it a dare?

Martin Berkhan said...

As a cheesecake master, it is crucial that I hone my skills every so often.

My Low Carb Road to Better Health said...

You're so funny! What the heck is a cheesecake master???

Martin Berkhan said...

Don't spread this around but the Cheesecake Masters is a secret society bound together by a sacred vow to conquer and do battle with giant cheesecakes. There are only a few of us left now. It is written that this eternal struggle between us and the cakes is what keeps the world in balance.

Various conspiracy sites will spread evil rumours about us controlling the World Bank and being the ones responsible for the financial meltdown of last year. Do not believe them.

My Low Carb Road to Better Health said...

Okay. You got me. I'm speechless. I've been so blind.

Ryan said...

Hey Martin, I'm sorry if you already answered this but is there an ETA when your book is coming out? I've been following your IF routine for a while now and I'm really interested in picking it up, any updates?

Martin Berkhan said...

Nope. Just because I suck with ETAs, which I have proven several times in the past.

One day you'll visit the site, there'll be some sort of announcement, and then the book will be released shortly after.

Anonymous said...

lol @ cheesecake society

you're wack

but in a good way:)

F. Belt said...

Thanks for answering, Martin! When I spoke of the cookies, etc., I was referring to the testimonials given as part of his presentation about what the book was about. He would tell a little bit in his own words, then give a quote from a follower, and they would say things about eating whatever they want, like cookies, cake, pizza, etc. So I naturally assumed that the book allowed for that kind of eating on a regular basis.

Tobias said...

Hey, Is endurancetraining in fast hours the same as in gym, that you should take 10g BCAA 5-15 min pre WO ?

Thank you!

Martin Berkhan said...

I will cover that in the next article on the subject.

Arvid said...

"Hell, look at me. I won't stop at one piece of cheesecake.

http://leangains.blogspot.com/search/label/Cheesecake%20Mastery

I'll eat the whole thing. But I don't do that on a regular basis and I'll lower calorie intake the next 2-3 days to get the water weight off.

The key point here is balance."

Martin,

How would you explain the difference between this behaviour of yours and a classic eating disorder behaviour with high calorie intake followed and compensated by a lower energy intake? I hope I don't make the impression of accusing you of anything, I'd just like to hear your comment on this 'cause I think it's a pretty important issue in this business.

Martin Berkhan said...

Sure thing. Great question actually.

Eating disorders are characterized by eating habits that affects the physical and emotional health of an individual negatively. No such thing in my case. I just love cheesecake and I don't feel bad about it.

The days following such excess my hunger is blunted - cutting down on food feels natural. I tend to follow my hunger; the thought of consuming my regular amounts of 3000 kcal+ feels unappealing. I lose interest in food. After a few days, my hunger kicks into gear again and I resume my normal eating patterns.

Same thing with holidays, birthdays, weddings and the like. I enjoy spending time with my family and friends, eat well and not think about calories, protein etc. I have no qualms about eating lots of "unhealthy" stuff in the short-term.

Now, for a person with an eating disorder, holidays and the like would cause tremendous anxiety and feelings of guilt. The compensatory behavior would likely be extreme - hours of cardio combined with very low calorie intake. I just cut down on carbs and fat while keeping protein high. IF makes the whole process a walk in the park.

I really don't see any other way of having a carefree social life while maintaining the lean state.

There's gonna be some days where it's just not possible to keep a perfect diet. You'll eat in excess, you'll gain some water weight and you'll probably put on a few ounces of fat. No big deal. It's easy to sort it out with a few days of moderate calorie restriction. If you don't sort it out, count on gradually getting fatter and fatter. That's how most people get fat. Excess intake which is not compensated for.

Anonymous said...

Martin,
Please forgive me for this question. It hasn't been appropriate for your past blog posts but I'd like to ask it at some point.

Lyle has discussed the problem of mobilizing the last few bits of stubborn body fat toward the end-stage of one's diet and introduced the necessity to radically change the diet/training protocol to get around these problems (preventing A2R-mediated vasoconstriction, keeping hepatic stores empty to keep ketogenesis ramped up, HSL activity up, limiting whole-body protein oxidation by limiting carbs - the one time a keto diet is warranted).

However, for your case and in the case of your clients, this phenomenon never has seemed to be an issue. Unless I'm mistaken, it looks like you take the IF diet all the way up to the end of a cut with no apparent problem with this "stubborn fat" that Lyle writes extensively on.

What do you think about Lyle's assertion? Do you in fact make modifications toward the end of your clients' diets that I am not aware of because I haven't trained under you? :)

Anonymous said...

Hi Martin...is it possible to build some muscle with high amount of protein and low kcal the whole time instead of cycles between high and low kcal. ive read on you blog somewhere that one should do high carbs/low on fat on workout days and vice versa,what is the reason for this?

btw..this is my favorite blog :D
thank you :D

Martin Berkhan said...

Anon nr 1,

I have an article on IF and stubborn body fat coming up in the future, so I'll save the details for then.

In short, I have never needed to complicate things to get rid of stubborn body fat on myself and my clients.

I am convinced that IF may work very well in that regard on its own (mobilizing fat from stubborn fat depots) and there is some scientific evidence to support this notion.

Martin Berkhan said...

Anon nr 2,

If you're a beginner, yes. If you're past the beginner stage, then no, you probably won't build much muscle if calories are kept low all the time.

Then again it depends on your definition of low.

Possible to build muscle on a high protein diet with a very subtle energy deficit on training days, with the majority of calories centered around training, and if your training routine is great? Sure. Seen it happen myself many times.

Possible to build muscle on -1000 kcal/day but also super high protein intake and excellent training? No.

justy said...

Regarding BCAA intake. I have taken your advice and am using them preworkout. Unfortunately I purchased the powdered variety. Tastes like butt quite frankly... any strategies on masking the taste until I smarten up and buy capsules?

Arvid said...

Thanks for such a fast and comprehensive answer. You should write something about it since disciplin and enjoyment as described tend to oppose each other, and it's probably not very common, nor easy, combining these two.

Take care

Anonymous said...

how many days a week do you IF? Also its easier for me to eat lunch everyday then fast 16 hours after... Does the time you fast matter? ie skipping breakfast/lunch and eating dinner everyday..

Anonymous said...

justy,

I'm not Martin, but BCAA powder tastes fine mixed with Crystal Light and keeps the pre-workout drink nearly calorie-free. The powder doesn't dissolve easily, but I can get most of it dissolved by using one of the mixers with a little whisk ball.

Anonymous said...

"Anon nr 1,

In short, I have never needed to complicate things to get rid of stubborn body fat on myself and my clients.

I am convinced that IF may work very well in that regard on its own (mobilizing fat from stubborn fat depots) and there is some scientific evidence to support this notion."

Well, this is news to me. And I wonder if you've discussed this with Lyle. On the one hand, there is a camp of trainees who seem to attest to the efficacy of

1) ketogenic dieting
2) yohimbine/caffeine
3) fasted high-intensity cardio followed by
4) low-intensity cardio

in order to mobilize and oxidize the stubborn fat.

I do agree with you when you say that IF incidentally does this. A 16-hour fast coupled with the use of stimulants that further increase HSL activity and the presence of free fatty acids in the blood may already mimic what the yohimbine is purported to do. That and the fact that IF trainees seem to ramp up their NEAT expenditure during the fasting phase anyway (doing chores and such, which qualifies as low-intensity activity), and it may add up. This is amazing. Your clients are getting over the stubborn fat "hump" outright without a second thought!

Anonymous said...

This is not directly related to the post, but how do you manage to get enough calories on rest days to be just a bit below maintenance if the majority of calories has to come from protein? If it's a maintenance level of around 3000 kcal, you'd want, say, 2800 kcal on a rest day, with min 50% from protein max 40% from fat and max 10% from carbs. That would mean that you consume 300-400 g of protein or more! Thats more than 2 pounds of turkey in an 8 hour period for instance. Do you really eat like that or have I misunderstood something?

Anonymous said...

Martin, is there a book or website you recommend that has good information on compound movement - circuit type training?

Chino said...

Martin, my apologies if it has already been answered before. Would taking creatine pre-workout be considered breaking the fast? Thank you.

Martin Berkhan said...

Justy,

Out of curiosity, what brand? Some powders taste great. Try it with some Crystal Light or Diet Coke.

Anon,

Everyday. Read the guide.

Anon,

No problem. You get used to it.

Anon,

Nope. Not a fan of circuit type training.

Chino,

Nope.

Anonymous said...

thank you for your response and i apologize for not finding the answer in the guide.

malpaz said...

science daily just published this article...fast weight training in women with followed milk vs sugar drink...

"Over a 12-week period, the study monitored young women who did not use resistance-training exercise. Every day, two hours before exercising, the women were required not to eat or drink anything except water. Immediately after their exercise routine, one group consumed 500ml of fat free white milk; the other group consumed a similar-looking but sugar-based energy drink. The same drinks were consumed by each group one hour after exercising.

The training consisted of three types of exercise: pushing (e.g. bench press, chest fly), pulling (e.g. seated lateral pull down, abdominal exercises without weights), and leg exercises (e.g. leg press, seated two-leg hamstring curl). Training was monitored daily one on one by personal trainers to ensure proper technique.

"The women who drank milk gained barely any weight because what they gained in lean muscle they balanced out with a loss in fat" said Phillips. "Our data show that simple things like regular weightlifting exercise and milk consumption work to substantially improve women's body composition and health." Phillips' lab is now following this study up with a large clinical weight loss trial in women."

FLo said...

nice article, and interesting also...I have one question : I want to start the UD2 diet and I am wondering if I can do the depletition workouts fasted ( your article inspired me) and consume my calories only Pwo, would that be detrimental to muscle mass ?

W: Eight said...

GREAT post Martin ... and very good news for me! I have been taking part in fasted morning training for almost 10 years now, and I've always felt great doing so. I eat a fairly high protein/carb meal shortly after my weight workouts which tends to be very satisfying. On cardio days I also train fasted, however I typically do not eat immediately afterwards, but wait for a few hours (with the hope of burning more fat). It has always amazed me that I actually feel stronger during fasted cardio than fed cardio.

Simon said...

True, the Kenyans typically train "fasted" - but from everything that has been written about them this is only their first, easy, wake-up run of the day. They do all their significant training after having eaten.

The challenge for endurance athletes is not whether it is possible to train "fasted" and subsequently see an increase in glycogen storage - that is only really important to a subset of runners anyway - but to what extent training fasted affects the quality of training.

If we're going to use the Kenyan as an example then let's be clear: their practice is to do their quality training after having eaten.

Martin Berkhan said...

Yeah, which is why I wrote

"...or complementary, to fed state training."

Superior as in: maximizes adaptations.

Complementary as in: even though adaptations may be accelerated with fasted training, you still can't run long distances with low hepatic and muscle glycogen.

Anonymous said...

why wouldn't they also look at the effect of a protein or fat based breakfast? Cereal? really?

Anne said...

Hi Martin, really interesting post!

Do you think it shows that women should eat something before morning exercise? I got the impression that fasting workouts are much better for men then women.

Something like lowfat milk and berries smoothie or just an apple so you won't have wait long, ofc with a proper meal directly after.

licia said...

I'm curious too, I would like to see more info pertaining to women. I just started IF and already, after 1 week, I have noticed my arms and abs now appear more cut. However due to a minor out-patient surgery I haven't been able to train much. My week of restricted training is about over now though. I guess I'll see how it works out for me fasted (with just BCAA's).

TSullivanM said...

How long do I have to fasten for it to count as a fastened state?

Is not eating for 3-4 hours sufficient or must it be a lot more?

Martin Berkhan said...

TSullivanM,

The clinical definition of the fasted state is usually after overnight fasting, so 10-12 hrs. Insulin must reach a certain low. 3-4 hrs is not enough

Anonymous said...

Martin,

As a competitive cyclist who has an interest in IF what alterations would you make to the regular leangains plan?

I've begun incorporating a couple shorter fasted workouts (maybe 1-2 1 hour rides per week) but otherwise try to take in a small carb/protein meal before workouts, with a huge post workout meal.

Thanks for any information.

And so far your 16/8 plan has really just done wonders for my mental health. I was borderline orthorexic before.

Andreas said...

Hi Martin!
About VO2 max adaptations:
VO2 max values are as much a result of genetic as muscle size. That goes both for base level and adaptability. A cycling training period of 12 weeks, with cycling 5 times/week and training planned to maximize VO2 max increments, will give individual improvements in the range from 0-30%. The training protocol in this study is not in any way close to what is used to maximize VO2 max. The improvement they see is likely due to skill adaptations (and some improvement in local endurance in the trained muscles) more than cardiovascular adaptations. As a general rule: only competitive cyclist (some duathletes and triathletes will also be capable!) will be able to obtain a true VO2 max value on a bike ergometer. Normal individuals will obtain roughly 90% of their treadmill value on a bike.

Andrew said...

This is a great post Martin. I had fun reading this post and i think i'm going to do some of your ideas.

Snel afvallen said...

I read about this more often, even on tv they did a test with long lasting exercises vs quick burst excersises. In the end the quick excersises had a better result.

asg0702 said...

Martin,

So overall, would you recommend training fasted for a teen who plays a sport involving lots of sprinting? I would like to start IF tomorrow and wonder if it will hamper not only my muscles but my energy level as well.

Anonymous said...

What protocol would you recommend for someone doing competitive run marathon training? If you train in the morning would you still recommend zero calories with bcaa supplementation until after noon?

Anonymous said...

Hmm.. nice blog.

I routinely do 40 hour fasts 2x a week. In the middle of the 40 hour fast (around the 20th hour), i also do 1 hour fitness, 30 minute run/abs, 30 mins weights).

So, basically fast, fitness, and feeding 20 hours after.
Fitness, body, fat-wise I am happy. Just wondering how the science would stack up for this to give me long-term perspective.

Anonymous said...

Hmm.. nice blog.

I routinely do 40 hour fasts 2x a week. In the middle of the 40 hour fast (around the 20th hour), i also do 1 hour fitness, 30 minute run/abs, 30 mins weights).

So, basically fast, fitness, and feeding 20 hours after.
Fitness, body, fat-wise I am happy. Just wondering how the science would stack up for this to give me long-term perspective.

Anonymous said...

Hmm.. nice blog.

I routinely do 40 hour fasts 2x a week. In the middle of the 40 hour fast (around the 20th hour), i also do 1 hour fitness, 30 minute run/abs, 30 mins weights).

So, basically fast, fitness, and feeding 20 hours after.
Fitness, body, fat-wise I am happy. Just wondering how the science would stack up for this to give me long-term perspective.

Crni said...

I would speculate that fasted group had a greater VO2 max increase because having their glycogen stores depleted they used more energy from oxidation of fat which in turn led to a increased respiratory work.

Since glycolysis isn't oxygen dependent need for it is somewhat smaller since it produces only a small amount of ATP compared to oxidative phosphorylation. But the difference might prove a contributing factor in VO2 max stimuli.

However I would question positive effects in competitive athletes whose homeostasis is a lot more disturbed and they generally don't fully recover between training sessions. It's an interesting concept to be used in recovery and basic preparation period and during tapering but very carefully if a serious competition is at stake.

Crni said...

I would speculate that fasted group had a greater VO2 max increase because having their glycogen stores depleted they used more energy from oxidation of fat which in turn led to a increased respiratory work.

Since glycolysis isn't oxygen dependent need for it is somewhat smaller since it produces only a small amount of ATP compared to oxidative phosphorylation. But the difference might prove a contributing factor in VO2 max stimuli.

However I would question positive effects in competitive athletes whose homeostasis is a lot more disturbed and they generally don't fully recover between training sessions. It's an interesting concept to be used in recovery and basic preparation period and during tapering but very carefully if a serious competition is at stake.

Anonymous said...

Martin,

I'm an actor getting in shape for a Broadway show. I have a masters degree in molecular nutrition and have been a big advocate of an intermittent fasting style nutrition protocol way before it's become "fashionable" - Which is much to your credit.

My Questions:

I know that you advocate BCAA/EAA use pre and post workout for morning training sessions, as well as periodic dosing of BCAA/EAA during the rest of the fast. This will certainly stave off muscle catabolism and possibly promote some anabolism, but does little to take advantage of the post workout calorie/carbohydrate enhanced feeding window. I'm mainly interested in your thoughts on the following:

Is there, in your opinion, a major physiological disadvantage to training in the AM vs training soon before breaking the fast with a large post workout meal (in terms of glycogen refill)?

In my opinion the former would be better for fat loss (enhanced fat metabolism in the hours following the workout) and the latter for muscle gain. Ori Hofmekler, also an advocate of this style of eating, seems to agree on that subject.

Thanks for your time.

Unknown said...

I theorize the increase in glycogen storage is in large part because of the strong dependance on glycogen alone during the exercise. The body becomes more efficient at storing glycogen in response to the dedicated demand for it in training. Studies show that feeding of CHO during exercise delays fatique by up to 45 minutes and feeding becomes important when glycogen levels start to drop significantly usually after 2 hrs of prolonged exercise. http://www.ncbi.nlm.nih.gov/pubmed/1936083 The exercise in the test you cited never exceeded 1hr40 min. so glycogen was the prioritized fuel source. Without feeding before or during training in the first 2 hrs. the body becomes more efficient at using available glycogen and also places a priority on it's resynthesis capacity based on the demand. Supplementation of CHO during or before exercise reduces glycogen dependancy. While increased glyc storage capacity is certainly an advantage, there is also the advantage of training in a glycogen depleted state with CHO feeding during exercise. This will increase the body's efficiency of CHO oxidation which is very important for high intensity endurance training lasting 2+ hrs. Therfore, I suggest a combination training regimen.

Anonymous said...

Yo Martin please tell me are bcaa a must for fasted training? In my city i cant find bcaas at all anny way i cant afford suplements at the moment, im bulking eating +500cals on training days +200on off days (low carb on rest days) can i get away with a full fasted training 50min in the morning and a hudge 2000kcals post workout meal or i absolutely nees bcaas or aminos? Thx for the advice bro




My name is Martin Berkhan and I work as a nutritional consultant, magazine writer and personal trainer.

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