Research Review

Melby CL et. al. Effect of carbohydrate ingestion during exercise on post-exercise substrate oxidation and energy intake. Int J Sport Nutr Exerc Metab. 2002 Sep;12(3):294-309. Links

Thirteen physically active, eumenorrheic, normal-weight (BMI < 25 kg/m2) females, aged 18-30 years, completed 4 experimental conditions, with the order based on a Latin Square Design: (a). CHO/Ex: moderate-intensity exercise (65% VO2peak) with a net energy cost of approximately 500 kcals, during which time the subject consumed a carbohydrate beverage (45 g CHO) at specific time intervals; (b). CHO/NoEx: a period of time identical to (a). but with subjects consuming the carbohydrate while sitting quietly rather than exercising; (c). NoCHO/Ex: same exercise protocol as condition (a.) during which time subjects consumed a non-caloric placebo beverage; and (d). NoCHO/NoEx: same as the no-exercise condition (b). but with subjects consuming a non-caloric placebo beverage. Energy expenditure, and fat and carbohydrate oxidation rates for the entire exercise/sitting period plus a 90-min recovery period were determined by continuous indirect calorimetry. Following recovery, subjects ate ad libitum amounts of food from a buffet and were asked to record dietary intake during the remainder of the day. Total fat oxidation (exercise plus recovery) was attenuated by carbohydrate compared to placebo ingestion by only approximately 4.5 g. There was a trend (p =.08) for a carbohydrate effect on buffet energy intake such that the CHO/Ex and CHO/NoEx energy intakes were lower than the NoCHO/Ex and NoCHO/NoEx energy intakes, respectively (mean for CHO conditions: 683 kcal; NoCHO conditions: 777 kcal). Average total energy intake (buffet plus remainder of the day) was significantly lower (p <.05) following the conditions when carbohydrate was consumed (CHO/Ex = 1470 kcal; CHO/NoEx = 1285 kcal) compared to the noncaloric placebo (NoCHO/Ex =1767 kcal; NoCHO/NoEx = 1660 kcal). In conclusion, in young women engaging in regular exercise, ingestion of 45 g of carbohydrate during exercise only modestly suppresses total fat oxidation during exercise. Furthermore, the ingestion of carbohydrate with or without exercise resulted in a lower energy intake for the remainder of the day.

My comments: For years, there have been a bunch of prevailing beliefs regarding exercise and fat loss including (but probably not limited to):

The idea of an optimal fat burning zone

The idea that fasted/unfed cardio burns more fat (some have claimed 300% more) than cardio done when you've eaten

The idea that you must do morning fasted cardio to lose fat or you're just wasting your time

And other amusing chestnuts.

I'm not going to address them all in detail. The fat burning zone is basic nonsense, based on a total misunderstanding of percentages versus absolute values. That is, while you may burn a higher percentage of fat at lower intensities, you often end up burning more total/absolute fat (in terms of grams) at higher intensities. Put simplistically, 100% of 5 calories is still less fat burned than 70% of 10 calories.

Additionally, it's questionable whether burning fat during activity is very important under most circumstances (one possible exception is getting rid of stubborn bodyfat). If you had to burn fat during activity, interval training (which relies solely on muscle glycogen) would not cause the fat loss that it does.

Finally is the idea that doing cardio fasted/unfed is critical to one's fat burning efforts. Various studies have found that consuming food before or during cardio (usually carbs) tends to decrease fat oxidation, that much is true. A question might be how much of an impact really exists which is what this addresses.

And it found a very small effect; importantly it looked at fuel oxidation for 90 minutes after the exercise bout. The difference between groups (both burned 500 calories, taking an average of 75 minutes to do it, and one consumed 45 grams of carbs while the other didn't) in terms of total fat oxidation was a whopping 4.5 grams. That's a 45 calorie difference in fat burned compared to the women having consumed 180 calories during activity.

Additionally, and perhaps more interestingly, the women who consumed carbs during training compensated by eating less at the meal given after the workout/the rest of the day. Which, arguably, has less relevance to bodybuilders and athletes who are eating a fixed amount but is still important overall. If training on an empty stomach ends up making you hungrier later in the day, that's a negative.

As an additional factor, which this study didn't address, I'd add this: intensity of training (and thus calorie burning potential) is often compromised when cardio is done on an empty stomach. Consuming even a small amount of carbs during training often lets folks maintain a higher intensity, meaning that they can burn more calories. And since caloric expenditure is a far greater determinant of fat loss down the road, you might make the argument that fasted cardio is worse than doing it while fed (or at least consuming small amounts of carbs).

Finally, I would add that a 500 calorie aerobic bout is actually a lot more than most people think. Someone walking slowly on the treadmill for 30 minutes isn't burning nearly that many calories, I'm not saying that they need the big bottle of Gatorade to fuel it. But when you start getting folks doing an hour at a decent clip, issues of blood glucose and maintenance of intensity become a bigger issue.

8 Questions with Matthew Perryman

Matthew Perryman is regular contributor to a number of internet forums including mine (where he posts as PowermanDL) and otehrs (where he often posts as PMDL or something similar).

1. Hi Matt, thank for joining us. Who are you and why should we care what you have to say?

MP: Thanks for having me

I'm just a guy with a very passionate interest in all facets of strength training. It's something that has consumed me for the better part of a decade now, and something that will certainly continue to do so

I first started working out in a weight training class in the last semester of my senior year of high school, back in 1998. Though you wouldn't realize it to know me now, at that point in my life physical activity was unheard of for me. I never played any sports or even had a remote interest in any type of human performance back then. It showed, too. I was tiny, hovering in the range of 110-120 pounds for most of high school

Ironically, I started out in the weight training class out of pure rebellious teenage laziness. I didn't want to have to take a "real" class, and I was already in a PE class (which I generally cut to go goof off), so I picked up strength training. I was the typical teenage bonehead of a lifter, of course. My training routine consisted of bench press and curls, with occasional shaky, overly high squats thrown in

However bad it was at the time, it ended up being a good thing. I started to see improvements in my body, and seeing myself get stronger created a rush for me that I still have to this day. I was pretty slack about it after graduation though, and even though I'd joined up at the local gym, I never really got serious about it until about late August that summer. I'd gotten frustrated at my inability to add any weight, being even more ignorant of diet than I was of training, and decided to crack down so I could add some size

I've been consistent with it ever since, and mark that as the actual beginning of my "career". From a humble start at 125 lbs, I've made up to as heavy as 225 (albeit a bit more plump than I was comfortable with), and am currently around 200 lbs after spending some time leaning out. Considering that I'm only 5'9 and have wrists only a bit over 6 inches around (I can touch thumb to forefinger on both wrists, and the middle finger will overlap), I don't consider I've done too bad for myself in that time

As for why anyone should listen to me....that's a very good question, and one that I even ask myself often. I readily admit that I have no formal education at all in the field, a fact which ironically tends to shock most of those that have ever conversed with me on the subject. However, I've always had a fascination with science, and such nerdiness has given me a better than average background in the relevant subjects like chemistry, biology, and physics. I'm far from an expert in any of those areas mind you, but I have enough of a comprehension that exercise science just seems to "click"

I am college educated, though in a completely unrelated field; my degree is a BS in criminology. The interesting thing is, my classes were very oriented around research and critical thinking (the latter being IMO the most important ability one can have in this field). As I tend to be an analytical and critical person in general, I've been told I have an ability to problem-solve and see through a lot of BS that's taken as gospel. Considering the amount of mythology that's paraded around as "accepted facts" in this field, being able to look at things objectively and ask "why?" an absolute must

I consider myself quite lucky to have stumbled on to "the right people" pretty early on. Because of that, I've been listening to a lot of very smart and very adept people with regards to physical training for most of the time I've been involved, and it's largely to them that I credit the knowledge and capability I've managed to develop over the years. I've been arguing the topic on Internet forums since like 2000, and by this point I must certainly have the equivalent of a master's in trolling

I'd say that my strengths are not so much the fact that I can create things, but rather the ability to keep a practical perspective and to see through the fluff and myopia that can build up around information.

2. Tell us about your own past athletic accomplishments or current goals.

MP: I've already mentioned the weight gain I managed for myself. I consider taking myself from a tiny 125 lbs to a respectable 200+ lbs to be the most impressive thing I've done to date.

About 6-7 months into lifting, I stumbled across Fred Hatfield's web site. It was at this point that I became enthralled by powerlifting. It really spoke to me, as at the time I was more interested in being able to move heavy things than I was in getting huge or ripped. This was fortunate, as even though I had no plans of competing, it did shape my training in a very positive way. Ever since then, I've always based my training around big compound exercises with heavy weights.

I've never really considered myself to be strong enough to compete, and although I realize consciously that there is no "strong enough" since PLing is a very individual sport, there's some sort of subconscious hang-up I have about getting in front of a crowd and putting myself out there like that. Nevertheless, it is on my list of "things to do" at some point, and I'll make myself do at least one meet before it's done with.

My numbers in that area have never been phenomenal, in my opinion. At my strongest, I've managed to pull 500x5 and 525x3 in the deadlift, which has always been my favorite and strongest lift (hence the "DL" in my screen name). I've done a full-squat triple with 395, and a IPF-style PL squat (meaning, well below parallel but not quite a high-bar close-stance) triple with 405, both with nothing but a belt. Decent I suppose, but I still don't consider it anything spectacular.

My bench and overall pressing strength I don't even want to talk about. Needless to say, they're abysmal though I am taking steps to improve them. I've been in touch with Bob Youngs from EliteFTS, who runs Southside Barbell about 30 minutes from me, and I'm wanting to get up there to bench with them on Saturdays as soon as I can get my work schedule to cooperate. I do try to keep in mind that the lifts I have are well beyond what most "average people" could do, but I've always set the bar for myself very high.

Beyond that, there's a few other sports I wouldn't mind competing in if I ever get the time and have the motivation to do it. Olympic weightlifting has appealed to me for the same reasons that PLing does. Strongman, same idea. I've even recently toyed with the idea of some sort of martial art, most likely boxing/kickboxing or some sort of mixed martial arts competition. Even bodybuilding hasn't been completely ruled out, though the odds of me actually getting on stage in a thong are very very small, and for other reasons besides the fact that I hate dieting. Physique competition holds very little appeal to me. While I'd prefer to keep my body fat low just for reasons of general aesthetics, I can't bring myself to be interested in such a subjective image-oriented competition.

As far as immediate goals: First and foremost is to get my body fat down to around 10% or so after my multi-year bulk-a-thon. I'm tantalizingly close, but seem to have hit yet another plateau that I'm currently working to break. In the near-term after that's accomplished, I want to add another 5 to 10 lbs of LBM while minimizing if not eliminating fat gains. Easier said than done, but I'm confident it's doable. As far as strength, I'm wanting to get my deadlift up past the 600 lb mark and start to work with my bench shirt in hopes of bringing that lift up.

3. What's the best piece of training advice you've heard lately?

MP: You know, this is actually harder to answer than I thought it would be.

In a general sense, it's the recurring theme of "don't overcomplicate". Keeping things as simple as you can to allow progression at any given stage of training.

For specific advice, I'd have to say it'd be a tie between Pendlay's commentary on periodization in the ubiquitous 5x5 threads all over the Internet, which directly ties into the above, and your own comments about body part specialization. A lot of people try absolute dumbass means of bringing up lagging parts, or worse just take the defeatist mentality that it can't be done.

4. What about the worst?

MP: Oh, now this one's easy, but at the same time it has so many possibilities for specific examples that I don't even know which to put here. As you may or may not know, I'm on a lot of forums dealing with all types of fitness. I'm only active on a handful, but I read plenty and I get to see all kinds of stupidity.

Off hand, I'd have to say that in general, it would have to be bodybuilding nonsense that gets peddled around. Meaning, the mentality that bodybuilders have to train by "blasting the muscles" using some exotic system of exercises, sets, and reps that will "bring out separation", "define the muscle", and all that static.

While I think *some* of this may have merit, I also think it's a much greater disservice in that it takes the focus away from the truly important matters. Things that are either of minimal importance (ie, exercise selection) or should be relegated to assistance work (all the Weider-ific "shaping" approaches) are given some overblown priority, and thus the important basics are ignored.

5. Who in this field has influenced you and who do you listen to?

MP: Oh where to start. I mentioned earlier that Fred Hatfield was my first influence. Dr. Squat served as a gateway for me, leading me to other like-minded people. I found Jason Burnell's Deepsquatter website not long after, and began reading everything there. I was especially interested in the writings of Louie Simmons.

At some point, I made my way over to Mel Siff's Supertraining list. I took a lot away from there not so much from the direct information offered up, but in the fact that this was the first time I was actually forced to think and to look at everything with a critical eye. Mel took a lot of criticism for being overly wordy and vague, and not all of that criticism was unwarranted IMO. However, I did pick up a critical eye which has stayed with me ever since.

These days, I actively seek out as many viewpoints and opinions on the matter as I can. At this point, I feel that having many tools in the toolbox is an absolute necessity. There is no One True Way(TM), and everything has a place. Yes, a lot of coaches and other assorted experts will wrap up their particular approaches with some degree of proselytizing; that's just the nature of the game. You'll also find an inordinate amount of people with crazy or outright retarded ideas. With that in mind, I think that (almost) everybody's got something to offer. The rest is a matter of being able to distill the useful components and finding the appropriate context for that information.

If I had to give a brief list of current people I listen to, certainly incomplete and in no particular order: Louie Simmons, Gary Valentine, JV Askem, Ed Coan, Dave Tate, Glenn Pendlay, Alwyn Cosgrove, Jim Wendler and most everything on EliteFTS, Pavel, Eric Cressey, Bryan Haycock, Dante ("DoggCrapp"), Dave Draper, Anthony DiTillo, the Metal Militia guys, pretty much anything written by the old-school guys, Dan John, Dave Caster, Charlie Francis, Martin Rooney, the translated Soviet authors, our buddy Steve Shafley and the rest of the Power & Bulk guys, of course you know I love a good training wank-a-thon with you and the rest of the BodyRecomp crew as your input is always appreciated.

I like to take things from both the science-wank and the practical side of things, and as far as my own training is concerned, I listen to those "in the trenches" more than anything else. A lot of the technical discussions I like to have are just that, discussions.

6. If you had to give trainees a single important piece of training advice in terms of making gains, what would it be?

MP: Don't overcomplicate things. Use the simplest possible approach that will provide you results, and be consistent.

This seems to be the biggest mistake that everyone makes when starting out, and somebody's success with regards to getting the most out of training seems to be how effective they are in doing this.

You see so many people that get obsessed with every last single detail of their training -- Should I do 5 sets of 5 or 4 sets of 6? Should I rest 60 seconds or 90 seconds between sets? Should I do barbell bench press or dumbbell bench press? They end up focusing on all this irrelevant minutiae, and don't focus on the big picture: adding weight to the bar.

Everything that you do in the gym will ultimately boil down to that key factor, and everything you do should be oriented towards this, be it directly or indirectly.

7. A few months back, I finally pestered you into writing a book about training, how about telling my readers a little bit about it? What do you intend to cover in terms of information, application, etc. When do you think it might get finished?

MP: Yeah, that monster is finally starting to shape itself into something that looks halfway decent.

Deciding on a target audience and topics to include was a project in and of itself. Training books will tend to follow one of two approaches. You either make it a technical wank-fest that is all science and no practical usage to anyone, or you make it a training manual that outlines things in a rigid, step by step format. Very little seems to be a middle ground of any type.

I'm trying to put it in that zone. How effective I'll be only time will tell. The book, as of this writing, is divided into three parts. The first deals with the absolute basics. I'm talking never been within 100 yards of a barbell basics. I want this to be accessible to the teenage kid just starting out as well as those more experienced. The second part is pure science and research, along with some conclusions drawn from that research. I'm going into everything from the basic biochemistry of the body to neurology to the organization of training. Part three is where the meat of the book will be. There, I'm covering the practical matters of training, from what you're actually doing in the gym to how you should prioritize things (as in the point I made above about not overcomplicating things).

And I'm going to try and squeeze all this into a normal sized book. While I realize that you can't make everyone into a knowledgeable expert with a single book, I'd at least like to get people pointed in the right direction with a decent foundation on the subject. I won't be teaching the people to fish, but I'd like to make sure they know where the sporting goods section is.

At the same time, I'm expecting it to at least shed new light on some things for the vets as well. Not in the sense of providing anything new really. The fundamentals are well-known, it's only the interpretations and implementations that vary. By laying out the way the body adapts at the cellular level, you really start to see why the stuff we do works and the commonalities between the effective training systems start to become apparent. If nothing else, it'll be a new perspective as compared to most things on the market.

To my surprise, it's actually coming together quite nicely. At this exact moment, it's up to a bit over 80 pages and I'm estimating this to be 30-40% of the final length. As for a time of completion, I'm keeping my fingers crossed for late Fall to early Winter. I'm a slow but steady writer, meaning I don't put a lot down at once, but I do a little bit very often.

8. In your own training past, what would you say was your worst mistake? Put differently, if you could go back and time and train more effectively, knowing what you know now, what would you do differently?

MP: I can think of a few things I'd change honestly.

The biggest mistake by far would be obsession with trivia. Yeah, I was the worst offender on this back in the day, which is why I harp on it so much now. I was always so worried about finding the "perfect" program that I'd end up missing the big picture, not realizing at the same thing that there was no such thing. The "perfect" program changes from session to session, and depends on what the last session was. Adding weight to the bar and doing things like building up to peak weights and allowing time for recovery became secondary concerns to having exactly "right" exercises, weights, and volumes.

As a corollary to this, to get slightly off topic, science doesn't have all the answers. When I say science, I mean academic studies. Real knowledge, as to what you should actually be doing in the gym, will come from the strength coaches, and although there is a sort of "science" at work, a methodical, systematic approach in and of itself isn't what I'm talking about. Don't get me wrong, science is good to validate and can give you some great "oh yeah" moments when you realize that a particular study is describing why some particular approach works. Some of it can also be useful for deriving starting points for practical recommendations (things like Rhea's meta-analyses or Fry's work on effects of intensity, to name a few examples that are on my mind). But people that just take studies, usually just the abstracts at that, and throw them out there as "useful" are doing as much if not more of a disservice than those that regurgitate the mythologies of fitness, especially when they point to no real-world applications of the information. What's easier to debunk, a guy saying "I do this because that's what the pros do" or a guy saying "I've got a study that says...."? The guy with the study can be just as guilty of myopia or talking out of his ass, but he's got instant credibility to Joe Average because the science supposedly validates his position.

The importance of diet would be a close second. I knew I had to eat, but never kept track of how much or what I was eating. I stayed at a plateau of about 160-165 lbs for a few years before I finally got sick of it and started stuffing my face. After adding 30 lbs in about 8 weeks, going from 165ish on New Year's of 2003 to 195 lbs at the end of that February, the importance of diet finally hit home to me. While in retrospect I gained too much fat to make it something I'd recommend to anyone except those in desperation, it was a valuable lesson. Ever since then, I've tried to read as much as I can about nutrition and how to apply it in the same practical sense.

Too much focus on super-heavy weights and neurally-oriented training. This is a big one, and pretty specific to me since most seem to do the exact opposite, but I'd like to throw it out. This is a case of somebody taking the pendulum swing too far if you will. I was so hell-bent on lifting heavy weights that I spent a lot of time in the 1-3 range, grinding out sets as heavy as I could. While this is fine sometimes, it's no way to train all the time. It's a wonder I didn't get hurt. Almost every non-elite should spend the bulk of their time working with higher volumes and non-maximal intensities, in order to spend time building up the body's tissues. Occasional forays into the super-heavy stuff are fine and even recommended, but shouldn't be the foundation of a non-elite's training.

Questions and Answers

Q: Hey Lyle, just wanted to say I love the newsletter and always look forward to it showing up in my mail box. I have a question related to maintaining a healthy body fat percentage year round for men. Over the last fours weeks I have been following a contest diet, which I will continue to follow for another 4-6 week to see how shredded I can get. I am doing this basically as a way to look super lean for the summer and to give myself a mental and physical challenge. Once the diet is over I want to get back to a body fat % of around 8 or 9% and maintain that for the entire year. What is the best way to maintain this level of leanness for an extended period of time, especially for someone who was not given genetics conducive to getting and staying lean? thanks a bunch keep up the great work on the newsletter.

A: This is one of those perennial questions which I semi-addressed in the article last week. Fundamentally, keeping weight/fat off isn't difficult; it's practically where it can be a problem.

As well, regardless of where your bodyfat percentage ends up, the same fundamentals apply: you have to avoid going into a positive calorie balance again or you will regain bodyfat. That is to say, regardless of the adaptations that occur with dieting (including but probably not limited to a decreased metabolic rate, decreased fat oxidation, etc.) if you don't provide your body with excess calories, you don't magically start regaining bodyfat.

The difficulty is that, as you get leaner, the body fights you back more. Chronic hunger (stimulated by the hormonal changes that occur) can drive higher food intakes; coupled with the other adaptations, fat regain starts.

So, it comes down to still controlling your food intake. Now realize that, after active dieting, you can increase food intake to return to 'maintenance'. If you were losing 1 pound of fat/week at the end of your diet, you can eat roughly 500 calories more/day when you return to maintenance. Additionally, after a couple of weeks eating at maintenance levels, at least some of the adaptations that occurred during active dieting will fix themselves somewhat (they won't ever return to 100% normal unless you get fat again).

Basically, you have to keep your food intake under control. And, of course, maintain your activity levels. Quite a good deal of research has found that exercise actually has its greatest role in bodyweight maintenance, moreso than weight/fat loss per se. If you're finding appetite control difficult, adding a bit more activity (cardio) to offset it may be helpful.

Of course, doing the things that help to spontaneously control appetite (sufficient protein, moderate amounts of less refined carbs, moderate fat intake, plenty of fiber) helps. The ephedrine/caffeine stack or a green tea/caffeine stack to offset the metabolic effects wouldn't hurt either.

I still think that having one or two free meals (or even short refeeds) per week is useful, even during maintenance. Psychologically, allowing a couple of meals per week where you can eat relatively normally (just don't turn it into a high fat binge-fest) can help with eating the rest of the week. My Guide to Flexible Dieting discusses all of this in some detail.

Q: The information on dairy and artificial sweeteners is so contradictory. Bodybuilders avoid dairy because the sugar from lactose impedes fat loss; however, some experts claim the whey protein and calcium have a synergistic effect that encourages weight loss. Artificial sweeteners supply no calories, yet have been touted as fat loss stoppers because their toxic effect traps fat in the fat cells. Is Splenda as bad as aspartame? What is your position on these two substances?

A: Well, I addressed dairy a few weeks back with a review on the issue and one or two pieces of feedback. I think bodybuilders are way too fixated on insulin in terms of a lot of this. Consider, for example, that adding protein to carbohydrate (which is usually suggested to lower the glycemic response, which it does) accomplishes this by increasing the insulin response. Yet almost no bodybuilder would recommend avoiding that combination and, the simple fact is that people get plenty lean doing that despite a higher insulin response.

To add to the confusion, at least one study could be interpreted to suggest that an insulin spike would be better from a fat loss perspective. Let me explain. In that study, scientists wanted to examine the physiological effects of low and high GI foods; but to keep variables to a minimum, they gave both groups 50 grams of pure glucose. The difference was in how it was given, one group was given the entire thing at once (high GI), the other sipped the glucose over several hour which mimics a low GI food. What they saw was partly what you'd expect, the high GI group spiked insulin, blood fatty acid levels plummeted, etc. But, shortly thereafter there was a big rebound. When blood glucose crashed, blood fatty acid levels came way back up. In contrast, the low GI group showed a low but steady insulin response but, get this, blood fatty acid levels were suppressed over a much longer period of time.

Now think about what the goal of a fat loss diet is: it's to mobilize fatty acids out of fat cells so that they can be burned. And this study found that spiking and subsequently crashing blood glucose (and insulin) led to greater blood fatty acid levels than maintaining constant levels. This might suggest that small amount of high GI carbs during meals would be better, you'd spike and crash blood glucose and get more fatty acids into the bloodstream (read: out of the fat cell).

Of course, the problem above is that the crashing blood glucose would probably make people hungrier and make it harder to stick to their diet. There is also the issue of what would happen in terms of protein and muscle loss. I'm simply bringing it up since I think the whole issue of insulin has been overblown somewhat.

As far as artificial sweeteners, I'd love to see something showing that a 'toxic effect traps fat in fat cells'. This is voodoo bullshit as far as I'm concerned. The bigger issue in my mind is that, in some people, artificial sweeteners can stimulate hunger. If you eat more, you lose less fat.

Perhaps more importantly, the cult of the clean seems to be growing in force and extremism, they manage to find the most amusing (if nonsensical) reasons for why a given food isn't clean and should be avoided while at the same time rationalizing why some foods are clean and can be eaten.

But bodybuilders tend to think in terms of the following "The more miserable I can make myself on my diet by avoiding anything that even might remotely taste good or give me pleasure, the better off I'll be."

Orthorexia anybody?

Q: Hi Lyle:

What are your thoughts in regards to us group fitness instructors (I've been teaching for 21 years) who teach a lot of cardio classes yet still have a hard time losing body fat. It's hard to teach hard classes (especially indoor cycling) when you drop your calories and it's hard to workout much more when you already teach 4-5X a week. Have we truly adapted to our workouts? I do a lot of weight training and it seems that I have to move between 1200-1600 consistently for about 10 days to see and feel even the slightest results. (And, I'm good about my protein/carb/fat ratios and eating about every 3-4 hours.)

I don't lose muscle easily, either and I actually have a lot of LBM (15.5% body fat right now), but legs and butt definitely carry a higher ratio - which is why I am trying to lose just a little bit more - to even out.

Any thoughts.

A: This is an interesting question since there is some odd work in female endurance athletes (usually runners) that relates to your question: oftentimes researchers find female athletes reporting fairly low food intakes (relative to their energy expenditure) yet still being weight stable.

There are typically two explanations given for this.

1. The women are mis-reporting their true food intake. Given how bad many people are at tracking their food intake, this is a possibility.
2. Their bodies have undergone some type of metabolic adaptation

And, as always, data exists to support both possibilities. Some of it finds no effect on metabolic rate suggesting underreporting of food, some of it finds an adaptive drop in metabolic rate (usually associated with the loss of menstrual cycle). I can't find the paper but work has also indicated that too big of an imbalance between energy intake and output can affect metabolic rate (by affecting LH pulsatility) before effects on menstrual cycle are seen. Given that females can have up to a 5% bump in metabolic rate during certain parts of their cycle (due most likely to progesterone) this could be having an effect.

Another possibility occurs to me, some studies (often in older individuals) find that excessive levels of activity lead to spontaneously lower levels of activity later in the day. Fatigue from the large number of classes you're doing may be causing you to subconsciously reduce your activity at other times. Which adds up to a lower than estimated maintenance level.

So, how to lose fat under those conditions, without sacrificing performance. Of course, you didn't mention your bodyweight so it's hard to tell where 1200-1600 calories/day falls. And, female lower body is the most stubborn to move anyhow. At 15.5% bodyfat, your metabolic rate is probably already a little depressed (as a function of the hormones involved in all of this, leptin, insulin, thyroid, the same crap I talk about every week it seems) and that can mean low calories even with reasonably high activity.

Keeping carb intake up during your classes (see this week's research review) may be the way to maintain performance, while allowing you to cut calories/carbs at other workouts. It sounds like you've found a workable caloric intake to get some fat loss moving, just realize that, at 15% bodyfat, it's not going to be fast no matter how you cut it.