Nyligen hade jag och Jonathan Fass (som många kanske känner igen från The FitCast) en ganska lång diskussion om fastande träning och slutligen om periodisk fasta över lag. Jonathan har bl.a. en doktorstitel i sjukgymnastik och har framförallt ett ruskigt kritisk och objektiv tankesätt.
Till en början tyckte jag att han kringgick mina frågor och argument något, men till slut delade han med sig av en hel del vettiga och intressanta åsikter. Han var över lag ganska kritisk till periodisk fast (PF) och menade att han aldrig skulle testa det för att han var säker på att han inte skulle klara av det. Just det påståendet hängde jag upp mig lite på. Han fick det att låta som att PF var något plågsamt, vilket det verkligen inte är. Dessutom har jag själv varit med om ett flertal personer som har gått från att tidigare inte kunnat gå utan mat i mer än ett fåtal timmar till att ha anpassat sig till PF helt utan besvär. Har man verkligen testat PF i minst 2 hela veckor och sedan påstår att man inte klarar av det så säger jag absolut ingenting. Måltidsfrekvens är ändå ganska individuellt, men det är betydligt fler än man tror som kan anpassa sig till PF utan större problem.
Efter att jag i slutet av konversationen hade taggat Leigh Peele (även hon är del av The FitCast) i en av kommentarerna, så började även hon skriva. Hon bidrog med ett antal väldigt tänkvärda resonemang. Leigh är verkligen ett av de mest aktade namnen inom nutrition och träning. Hennes synvinklar på vardagstillämpning och psykologi i samband med diet och viktnedgång är fenomenala. Bortsett från alla The FitCast-podcasts så kan jag även varmt rekommendera Leighs egna podcasts!
Sist men inte minst anslöt även Alan Aragon till diskussionen. Jag skulle vilja påstå att Alan är minst lika respekterad som Leigh, men på ett annat sätt. Det Alan kanske inte har på den pedagogiska och psykologiska biten väger han upp med sitt kritiska tänkande och en fruktansvärd koll på den största majoriteten av forskningen kring allt som har med nutrition, träning och kosttillskott att göra.
Här kommer konversationen som började med denna statusrad:
In other words, eat something before you train (basically). Did I miss something...Are we still having the "don't workout on a fasted stomach" conversation??? An investigative study into the influence of a commercially available carbohydrate-protein-electroly
I will have to read up on this I guess. In playing with IF over the past month I've done lots of fasted workouts. Not the right thing to do?
Exercise on an empty stomach robs you of your energy, which means that your workouts will likely suffer. The advantage in substrate use (such as "burning" more fat, if there is such an advantage in real-world results) is probably offset by inconsistent energy expenditures within the workouts and the very likely possibility of reduced muscle hypertrophy or retention. The evidence is fairly clear on that, which is why there's been such a focus on pre and/or post-workout nutritional strategies in research and the field.
Kara, if you're doing the low volume RPT-workouts that are part of the leangains protocol then I'm pretty sure that you don't have to worry a lot about maintaining plasma glucose concentrations.
I recall some studies been done on lifters during Ramadan fasting, showing no decreases in performance.
Marek, were these trained athletes or recreational lifters, which would likely complicate the applicability of the results, as well as exercise timing relative to the breaking of the fast, etc. But I do agree, the impact on performance and/or results may be negligible depending on your goals and lifting/exercise design. As a general, however, I think that it's still clearly safe to say that fed>fasted in terms of performance and/or strength and muscle outcomes.
In general, I find that people who are using some type of fasting protocol such as Leangains, Eat Stop Eat, etc. tend to have a handle on their diet (both with regard to intelligent composition and appropriate caloric level) as well as properly designed training program, which the general public tends not to have locked down.
Jonathan, mainly trained athletes I think. Check out myth nr. 9 "Fasted training sucks. You'll lose muscle and have no strength." in Martin Berkhans "Top ten fasting myths debunked" http://www.leangains.com/
He has a bunch of references in there.
I'd be interested to see any well designed studies out there that show any negative effects of fasting on sports that mainly rely on the phosphogenic energy system.
What would have been the physiological limitations for these kind of sports in your opinion? I mean, if the activity doesn't depend on circulating glucose, why would pre workout nutrition be a limiting factor for performance? Maybe that would be something to discuss at the fitcast? I'd love to hear you guys talk about this!
Otherwise I recall a discussion between Kevin, Mike Boyle and you (Fitcast ep 160 or something) where you guys talked about not going over the top of another coaches advises, or judging a single element from a whole training/nutrition program without knowing the whole picture.
I'm most familiar to the leangains approach when it comes to IF. And the reasons to why you often are prone to train in the fasted state are much more complex than the statement that one would be equally as energetic as feed training. And, as you can see, Martins clients clearly don't have any problems with their muscle outcomes.
Though I should note that Martin always recommends BCAA's before fasted training for reasons he explains in the link above.
Thanks Marek. The first study is an analysis of elite male athletes, so we can't really draw a direct conclusion from that to an "average" individual (especially an analysis of Ramadan, which is a very different experience for a practicing Mulsim who has done this his/her entire life vs a Westerner first attempting IF). The others are evaluations of endurance training (the post 3.5 days' fasting study is interesting, as are the points on fluid use as a confounding variable), which won't add value to a discussion about weightlifting specifically. These show potential for a trend, yes, but they don't yet achieve the value of the larger body of research that shows significant performance impacts, which MB acknowledges at the end of the article (and suggests amino acid supplementation because of, which I would completely agree with). I would think that variables like genetic potentials and training age would have an affect here, too, where some would do much better than others with an IF protocol, where some individuals may be more successful than others would be. In essence, the article is cherry-picking, and doesn't reflect the entirety of the research that has been performed to date. I think that, at best, we might be able to say that an individual *might* see weight loss results with minimal and maybe no impact in muscle retention, but we cannot yet make these statements for the general population, and the evidence would still suggest that there will be performance and lean mass impact.
I appreciate that you're taking your time for this conversation.
You *might* have a point there. But shouldn't the margins for performance be smaller for trained athletes than for average individuals? So if there aren't that great negative impacts on them then shouldn't the impacts be even smaller for average individuals?
Someone who has been IF'ing for one year has as much fasting experience as an adolescent Muslim who does Ramadan fasting one month a year. You make it sound like IF would be something that's hard to do. Have you tried it?
Regarding your point on age and genetics and so on, MB works with average Joes and Janes in different ages. Are you somehow insinuating that MB has been manufacturing the results of hundreds of clients when he says, quote:
"I get predictable results - fat loss and concomitant strength/muscle gain is the norm. Fat loss with full strength/muscle retention is worst case. Every client lost fat and saw an overall strength/muscle increase compared to start (stats from before-picture). Variance is low, there's no second-guessing, same overall result with everyone. Only the magnitude varies depending on weeks spent on program, compliance and genetics, etc. " ?
I'll answer this in a few parts, because it'll be too long to post in one (FB size limits)
1. Elite athletes do not represent average individuals, ib muscle, performance, recovery, injury rates, or just about any other measure. You can't draw direct 1:1 correlations between the subjects. Look at it this way: would you draw conclusions about the effectiveness of a basketball training program that was tested on professional NBA Power Forwards if you were a 5'8" point guard playing weekend ball at the YMCA? Of course not, those are two entirely different populations, with the most obvious difference being average height, but other less obvious could be training facilities, stress management, nutrition, age, overall support environment, access to medical care, rest, coaching, player experience, etc, etc. Can we draw certain themes or ideas? I'm sure that you can...but you can't expect the same results, because the subjects are entirely different. Wayne Gretzky famously did not weight train, and didn't believe in it, either. Does that mean that in order to become the best hockey player in the world, you shouldn't either? Bill Gates never finished college, Sir Richard Branson (founder of Virgin Atlantic) never completed high school: in order to become one of the richest people in the world, would you take their lead and drop out of high school and/or college? Obviously, what *may* work for some may absolutely *not* work for others: It's important when looking at research, and especially at anecdotal evidence, that you look for trends that may influence results in *your* particular population group and specifics. If you happened to listen to our FitCast series on the FMS, this was the same basic logic that we used to evaluate the current literature presented in the FMS: so while the results of the "Football Study" may have been interesting and very-much warranting of further study, there's no way that I can yet assume that the same results and conclusions could be made of a general population, i.e. clients like "Joe the Plumber" or "Mrs. Housewife" who walk through my training Studio's front door. Does that make sense? These indicate the potential for trends, but not universally aplicable facts. We absolutely need more data and greater population surveys than just a single study on elite Judo players.
2. An adolescent Muslim is NOT the same as an adult Westerner attempting IF in any way, shape or form, not in activity levels, environment, recovery ability, activity goals, and most importantly, physiology and psychology. There's NO way that we can draw any conclusions from that. And there's also no way that I've ever tried IF: I can barely make it between regular meals :-D And in some sense, that's also my point: while this MAY be an option for some individuals, it is likely a very *poor* option for others (I wouldn't expect to do well at all on an IF protocol from previous experience of not being able to eat on a regular basis). A few, select studies not only doesn't yet have the statistical power to undo the majority of the existing research and performance, but it *certainly* doesn't yet have the power to determine responder sub-groups, further decreasing its statistical power
As far as MB's experience, that's important; after all, if there was nothing but negative results, we wouldn't even be having this discussion in the first place! This is why Anecdotal/expert opinion as well as Case Studies *are* part of the evidence-based model; however, cause and effect cannot be concluded from these models, which is also why we must continue towards better research designs, such as the randomized control trial, the blinding experimenters and of subjects (the second, of course, being impossible in this subject), and larger populations with more specific controls. So again, for now, these results only give us the potential for trends, but not actual cause and effect. There's no way to say that we know for sure what has caused the results, nor do we have a full picture of its actual success:failure rate (how many people are able to successfully endure the IF protocol vs how many drop out, how does the protocol match-up to other, more "mainstream" diet/training protocols, what are the long-term results, etc, etc. Too many questions without answers.
Another issue, and this is significant, I think, is the idea of how these results are being "reported." This is NOT an accusation of Mr. Berkhan, who I do not personally know and have NO reason to believe that his opinion is compromised or influenced in any way for personal gain; however, as a general statement and analysis, we have to recognize that MB *does* have a financial "stake" in the success of IF as a tool and possible source of "income" in training clients, possible books, lectures, etc, etc. Think of how often you read a study about, for instance, the positive effects of milk in nutrition and performance, only to find out that the research was payed for by a grant from the dairy industry. Immediately, concerns of "financial conflicts of interest" are raised, and they *are* legitimate concerns. Whether or not we may or may not agree with the ideas put forth in research or reporting, we have to run them through the filter of the source of information. This does NOT mean that it's wrong...but we have to be cautious in how we accept information without question.
Could IF be a legitimate diet design? ABSOLUTELY. But do we *know* that it is just yet, given the limited information that we have vs the enormous amount of information that we have that would seem to contradict these claims? I would argue that we do not. Sometimes research will be developed that is able to further refine theories and highlight study flaws in earlier work, demonstrating more advanced understanding of findings, and sometimes even resulting in entirely different results (Einstein vs. Newton's laws of gravity, for instance); however, the claims of IF go *completely* against currently accepted theory AND results, real-world, performance, and laboratory. I think that we need to see a lot more before we decide that fasting really *is* better than other methods for overall health, weight-loss, performance, etc.
FYI, I was scolded by my gf for my examples of "Joe Plumber" and "Mrs. Housewife." She would like to point out that it could be "Mrs. Lawyer" and "Mr. Mom." I'll apparently be sleeping on the couch tonight :-D
Jon, it is worth being your friend on Facebook if only to read such responses. Thank you for taking the time to write that all out.
Thanks, Andrew...greatly appreciated :-) It's been a good conversation!
Thanks for the thorough answers!
1. I'm taking my Bachelor's Degree in biomedicine athletic training, so I'm very familiar with your arguments, and I fully agree on that point! But due to my limited ability to express myself in the English language I still wasn't really able to get my point across to you. I think I'll just skip that one.
2. My point here was the pure EXPERIENCE of fasting. If you do IF for a whole year you have 12 month "IF experience". To collect the same experience you'd have to be a practicing Muslim for 12 years. Get my drift?
Now you're writing about your "beliefs" when it comes to IF. Leangains is ALL ABOUT regular meals. I have yet today not met anybody who couldn't adopt to IF, if the individuals gave their body the time (about a week) to adjust. Ghrelin rhythm is an important factor here. Ghrelin rythm seems also to be the main reason why most people THINK they'd never be able to adjust to IF. Because if they skip a meal they get hungry, and there's nothing strange with that. But IF is NOT about skipping meals. It's important to eat at regulated times every day.
3. Your last point was very valid indeed, but also kind of the reason why I responded to your status update in the first place. It sounded like you were saying that "It's clearly a very bad idea to workout on an empty stomach! So all you idiots in doubt, stop doing it!" This study was far from strong enough to support a strong statement like that. And as you can se, there ARE a couple of studies that actually show benefits of fasted training.
So I only wanted to answer your: "Did I miss something...Are we still having the "don't workout on a fasted stomach" conversation???" Because this little study you posted here didn't really end the conversation, or did it? ;)
Once again, thank you for your time! It's always worthwhile talking to experienced and knowledgeable people like you!
*no* worries there about communication, my friend: your english is *infinitely* better than my Swedish (on account that I don't actually speak Swedish!), so you are WELL ahead of me on communication abilities! I understand what you meant about the psychological experience of it, absolutely. Incidentally, the Ramadan question is an interesting one, because, of course, Ramadan is a "structured fast" as well with specific meal times (at least first and last meals). However, referring back to my original claim about not being able to fast, when my gf read that, she thanked me for making that decision, because she knows how moody I can get when I haven't eaten :-D It's not an "I don't like not eating" argument, it's an actual physiological response that, quite interestingly, my family shares, too (my uncle responds most like I do, with changes in mood, energy, etc). So I still don't think that it would be something that I would be interested in...I'd like to keep my gf happy :-D As far as the original post, I understand that too, and completely agree: this, by itself, would have little bearing in any argument. When I read it, I was actually surprised simply because I didn't think that it added much value to the conversation *because* there's been so much previous work in "optimal" nutrition pre and post workout. It is only because it *does* correspond with the body of evidence (the same reason why I remain skeptical of "fasted" evidence) that it's even worth mentioning, IMO. However, you're absolutely right: I would like to get this on a FC discussion, too...if we ever record again sigh :-D
I'm still sticking to my point there. I challenge you to try it! Just for two consecutive weeks. If you after that period still feel that your mood gets affected during the fast then give in! :P
I've heard people complaining about these precise physiological responses to many times, and a lot of these people successfully adopted to IF later on.
I tried to explain these responses earlier, but I don't think it came through. Me and a colleague of mine are writing our Bachelor thesis on correlations between substrate absorption, blood glucose levels and hunger ratings. We've read up on a lot of the literature on that subject. Here are two papers on ghrelin. The main point there is that: "You get hungry (and possibly moody and loose energy) at times when you ARE USED TO eat." This is modulated by an inner clock, than most probably CAN be changed.
So the scenario "when I haven't eaten" will not occur because, you always eat when you should eat, according to your new pattern.
Ok, regarding that even leangains IF'ers supplement with BCAA before fasted training, a part of the optimal pre WO nutrition recommendations are met. My main point in the beginning was that in explosive sports, where the main energy used is stored energy within muscle cells, theoretically (and evidently) shouldn't be affected by carbohydrate ingestion pre WO.
THAT would be awesome if you guys (and especially Leigh) could discuss in a future episode!
In regards to the gherlin comment, you can alter feeding patterns (emotional and physical) but you can also alter cortisol rhythms. This can be a good or a bad thing depending on individual and even timing for said individual. While I appreciate the "try it, it can't hurt you" attitude, for some IF'ing can cause an increase the the "binge/starve" attitude, which we have seen fail time again in real work experiments (hence the whole skipping breakfast = fatter people). I have seen many be liberated from the 5-6 meal a day dogma, only to find now they can't eat without feeling stuffed from the short time window. Oh, how emotional eating shows her ugly head.
I appreciate IF'ing as a diet strategy (and use it mind you if in a deficit situation). At the end of the day, its just meal timing and I am getting a little tired of the drama and fluff about it. Hell, I was IF'ing at 7, big whoop. It isn't for everybody and after the initial fun wears off, there is still the reality of energy balance and low caloric burn the average person has to deal with. It is largely successful with men, like most diets, shocker. Women still have problems with it, like all diets. Their results are hit and miss both physically and with psychological need.
That being said, I thinking training fasted (with supplemental BCAA) is perfectly fine for SOME individuals. Circulating BCAA mixed with the overall circulating AA's in 24 hours of feeding should be fine for a maintenance situation. I think you find in mass gains or needing to increase conditioning beyond general training, performance consistency and growth could run into problems. I think that is a no brainier. The muscle fiber usage, type of training, type of sport, period of maintenance or slight surplus, etc is going to impact all types of responses here. With any situation we have to look at the variables at play and who is playing the game. Personally, I can do cardio all day without eating in at a moderate pace. The moment I utilize glycogen as a main source of energy, I need food prior or I will have aggressive rebound hypoglycemia. This has been tested with doing everything I can to increase insulin sensitivity, carb loads, etc. It doesn't matter, I have to eat/drink something on some level before I lift. I can point to many however that increase their performance and have held it for a long-term in a fasted state. There is also research showing increase in muscle synthesis in fasted stated.
It cut me off and I didn't get a chance to edit for grammar. In short, I think Jon made good points, but I can see room for more aggressive testing of fasted training and testing of meal timing in all types of training and dieting situations. I also think Martin is at the top of the game and I have yet to see him manipulate research to try and sell his point. He seems to be pretty balanced and will say "yeah, this stuff don't work for everyone." If the person who lives and breathes the research can make that statement, then I think there is something to it. From my personal research, I see pros and yes, cons to Intermittent Fasting. I don't think it needs personal experiment to see that, but if you are unhappy with your current dieting strategy, why the heck not give it a try. If you are happy, I guide by the "if it ain't broke, don't by the new hype version."
Hello oldschool JP Fitness people :)....... Just wanna add a couple things here. For exhaustive endurance events meeting or exceeding 2 hours, the bulk of the evidence shows performance benefits of pre &/or during-exercise CHO (or CHO + prot/AA) compared to overnight-fasted conditions. The benefits are quite consistent in designs that mimic multi-stage endutance events where the rate of glycogen resynthesis between back-to-back depleting events is critical. The testing protocol in the study Jonathan cited involved two exhaustive 90-minute trials separated by 2 hours, so the results were predictably in favor of the fed conditions. However, these results aren't necessarily applicable to a typical 60-minute training bout (especially strength training) whose performance limiting factor is not glycogen status. To illustrate this point, notice that the CPE beverage only benefitted performance in the 2nd 90-minute bout. No performance differences were seen in the first 90-minute bout between the fasted & fed conditions.
Thank you, Alan! That was the main point I wanted to deliver!
Thank you, Leigh, for your thoughts as well!
I recognized that "binge/starve"-attitude you mentioned there. I think that Andrew *** had a solid point in the beginning of this conversation where he pointed out that IF'ers usually have a better handle on their diet compared to the general public. Without that type of control IF might, as you pointed out, become dangerous.
Lastly I want to clarify that my "challenge" for Jonathan was in no way an attempt to "convert" him into IF or something. I barely wanted to state the point that feeding patterns can be altered and that one should not judge something without giving it a real try. I could try to play the violin for 5 minutes, be totally worthless at it and say that I'd NEVER be able to play it. But that wouldn't have been fair to say, because I don't know until I'd give it a real try.
With that said I'm very grateful for this conversation! Thank you all for your time!