Research Review

Meyer T Does cumulating endurance training at the weekends impair training effectiveness? Eur J Cardiovasc Prev Rehabil. 2006 Aug;13(4):578-84.

BACKGROUND: Due to occupational restrictions many people's recreational endurance activities are confined to the weekends. We intended to clarify if cumulating the training load in such a way diminishes endurance gains. DESIGN: We conducted a longitudinal study comparing training-induced changes within three independent samples. METHODS: Thirty-eight healthy untrained participants (45+/-8 years, 80+/-18 kg; 172+/-9 cm) were stratified for endurance capacity and sex and randomly assigned to three groups: 'weekend warrior' (n=13, two sessions per week on consecutive days, 75 min each, intensity 90% of the anaerobic threshold; baseline lactate+1.5 mmol/l), regular training (n=12, five sessions per week, 30 min each, same intensity as weekend warrior), and control (n=13, no training). Training was conducted over 12 weeks and monitored by means of heart rate. Identical graded treadmill protocols before and after the training program served for exercise prescription and assessment of endurance effects. RESULTS: VO2max improved similarly in weekend warrior (+3.4 ml/min per kg) and register training (+1.5 ml/min per kg; P=0.20 between groups). Compared with controls (-1.0 ml/min per kg) this effect was significant for weekend warriors (P<0.01) whereas there was only a tendency for the regular training group (P=0.10). In comparison with controls (mean decrease, 3 beats/min), the average heart rate during exercise decreased significantly by 11 beats/min (weekend warriors, P<0.01) and 9 beats/min (regular training, P<0.05). There was no significant difference, however, between the weekend warrior and regular training groups (P=0.99). CONCLUSION: In a middle-aged population of healthy untrained subjects, cumulating the training load at the weekends does not lead to an impairment of endurance gains in comparison with a smoother training distribution.

My comments: As the introduction to the abstract mentions, some people, due to their scheduling find that training during the week is nearly impossible. And while the standard dogma in terms of endurance training is that you have to train at least 3X/week (generally for a minimum of 20 minutes), preferably on non-consecutive days, this study brings that into question.

As indicated, subjects were either placed on a traditional training program (5 days/week for 30 minutes at 90% of lactate threshold) or given weekend warrior training (75 minutes at 90% of LT done on Sat/Sun) and monitored for 12 weeks.

Note: lactate threshold (LT) is generally defined as the highest intensity that you can maintain without fatigue, above LT fatigue generally occurs fairly quickly (in a few minutes anyhow). I want to mention that the argument over LT (as opposed to competing concepts such as anaerobic threshold, onset of blood lactate accumulation, threshold power, critical power) is neverending but ultimately kind of tangential to this study. Just think of LT as the highest intensity you can maintain without fatigue; LT is a pretty challenging intensity. 90% of LT is doable and some believe that working in that range gives the optimal endurance adaptations. But I digress.

In any case, over the 12 weeks of the study, at least in this population (untrained middle aged individuals), both training programs gave identical results. As above, this goes against the commonly held belief and may represent a workable schedule for folks who simply can't train during the week.

Alternately, someone might be able to train twice on the weekends and fit in a third workout during the week; it wouldn't entire surprise me if this gave even greater adaptations. In any case, this shows that getting most of your aerobic training done (again, in untrained individuals) can stimulate adaptations similar to spreading it out.

An interesting question is whether a weekend warrior pattern of weight training might be as effective as more frequent weekly workouts? Could someone train full body 2 days in a row and then take the next 5 days off and make gains?

Perhaps more interesting is that this ties in with a current trend in aerobic training methodology which is usually called block training. In block training, rather than spreading out hard workouts through the week, they are done in series. So a cyclist might do 2-3 days of high intensity interval work in a row followed by multiple days of rest (for recovery). In highly trained athletes, this may be a way to stimulate further adaptation by accumulating fatigue/training stimulus over several consecutive days and then allowing the body to adapt. I've had a couple of the bodybuilders on my forum use this kind of approach for bodybuilding with good results; I hope to write up the idea at some point in the future.

Feature Article

Body Composition Numbers Part 2

Part 1 is here.

Lower isn't better

Although I've mentioned this several times, I really want to drive the point home: don't equate lower bodyfat with better. Once bodyfat gets too low, in both men and women, hormone levels are disrupted. The normal menstrual cycle in women may stop (this is called ammenorrhea), indicating a problem with estrogen production. This tends to cause bone loss which is a very serious problem. In men not using drugs to maintain their hormone levels, testosterone can approach near-castrate levels as they reach the lower limits of bodyfat. Complaints of zero sex drive (and not being able to get it up even if the drive were there) are common among natural bodybuilders who get extremely lean.

And that's just the tip of the iceberg. Thyroid, growth hormone, IGF-1, metabolic rate, and the immune system are all severely depressed under situations of extremely low bodyfat (folks who are naturally lean are exceptions to this, I'm talking about folks dieting to that level). Cortisol, which is one of the big causes of muscle loss goes through the roof at extremely low bodyfat levels. It's all part of your body's normal adaptation to starvation (remember from an earlier chapter: dieting is just like starvation, just slower) to try and keep you alive. But it sucks from the standpoint of achieving optimal body recomposition. In case you're wondering, it's not uncommon to hear of professional bodybuilders maintaining 4-5% bodyfat year round, while eating everything they want, and still being able to put on muscle. This is possible because they have replaced their normal hormones (which are no longer being produced for the most part) with exogenous drugs. By using testosterone, growth hormone, thyroid, insulin, etc, etc, drug-using bodybuilders have side-stepped normal human physiology.

To your body, all of this makes sense of course. A bodyfat of 5% in a man is likely occurring because there is no food. Your body can't tell the difference between you starving it because you're a crazy bodybuilder or you starving because there's no food available; it reacts the same way. If there is no food, the last thing your body wants is for you to get your mate pregnant. Either there isn't enough food to keep it alive or you'll be dead before it's born, and unable to fulfill your fatherly duties (watching TV and drinking beer). So testosterone crashes to make it impossible in the first place. If you're starving, chances are so is your mate so that's a double whammy.

A woman with 12% or lower bodyfat wouldn't be able to bring a baby to term safely in the first place, so the body prevents it by shutting down the menstrual cycle. I should note that the reasons for the shutdown are actually more complex and some dieting women will lose their period at higher bodyfat percentages. It's actually more an issue of energy balance (intake minus output) than bodyfat per se, but that's beyond the scope of what I want to talk about here.

Some women look upon the loss of their period as a benefit, just one less monthly messy (sorry) hassle. But the bone loss and estrogen issue is not a joke, and can (will) cause problems down the road. Studies of female gymnasts and ballerinas are finding low bone densities similar to post-menopausal women. Certainly not the picture of a healthy athlete. And if the bone doesn't develop during puberty, it may never develop at all.

The same dynamics hold for performance athletes. While it's 'logical' to think that leaner is better (less weight to move around) at least for some sports, the extreme amounts of caloric restriction and training needed to get that lean can cause muscle loss and crater performance. Even if losing a few pounds of fat might make a cyclist climb better, if the effort needed to do it hampers training or causes hormones to crater, it may still not be worth it.

For those truly obsessed with body image, bodyfat percentages of 8-10% for men and 13-15% for women should be safely sustainable year round although it will require nearly fanatical devotion to daily diet and training (or having picked the right parents to start with). Yeah, you can cheat from time to time (it's actually a good idea for a lot of reasons) but for the most part you'll be stuck paying attention to your meals and training to an extreme degree. If you're not genetically blessed to be that lean, be prepared to be a little hungry all the time. And to be a total pain in the ass when you go out with friends; the key is to schedule your cheat/free meals around social events so you don't have to be that guy who goes out and won't eat anything (or worse yet, you take your cooler of chicken breast and broccoli with you). After seeing what a hassle it is to get and stay superlean year round, many people decide that it simply isn't worth the effort. Of course, this is always a personal choice.

While I'm sort of on the topic, I want to address the issue of how to effectively gain muscle mass while keeping bodyfat in check. A long-held empirical belief is that mass gains occur more effectively at slightly higher bodyfat levels. I used to think this was horseshit but, based on what we now know about hormonal dynamics (and how they respond to very low bodyfat percentages and energy intakes), I now think that there is an element of truth to this. People who insist on getting and staying super-lean simply don't put on mass effectively. They usually find that gaining a little bit of bodyfat in the first place facilitates mass gains, and allowing slight fat gains during the training cycle facilitates them even more.

At the same time, calorie partitioning tends to go south as bodyfat percentage gets too high probably due to changes in thing like insulin sensitivity (which gets worse as you get fat). As usual, it's all about finding an optimal range of bodyfat percentages where you get the most effective mass gains without getting fat.

I generally recommend that folks pick some reasonable bodyfat range in terms of a low-end and high end. So a male might first diet down to about 10% bodyfat (8% would be about the lowest they would want to go and that's probably pushing it for most) and then gradually gain weight and muscle mass until they hit 12-15% bodyfat. Then they'd diet back down (keeping the muscle mass of course), and then eat themselves back up. Over a number of cycles, this adds up to a lot of muscle mass gained while keeping bodyfat at a reasonable level. Of course, women would use higher absolute levels. 15-18% is probably a reasonable low end and 22-25% at the high end.

Which means that, if you're a male or female bodybuilder or bodybuilder wannabe, if you're above those numbers, you should diet down first, before trying to gain mass. Probably not what you wanted to hear but you'll regret it if you don't do it that way. If you're a male and start bulking at 15% bodyfat (or higher), you'll probably gain a disproportionate amount of fat and end up at 20% bodyfat or higher. And it will take you forever to diet back down. The same holds for females, just with higher numbers.

As a general rule, a natural bodybuilder getting ready for a show shouldn't start any higher than 10% for men (12% at the absolute highest), 15-18% for women. Not if they want to have any chance of coming into the contest in shape in a typical 12-16 week cycle. This means that you need to be at that bodyfat percentage when you start your contest prep. Which may mean dieting down in stages long prior to that.

Ok, summing up since this article has been all over the place. Bodyfat percentages for men and women under a number of different conditions appear below.

Women tend to be a little more variable than men, some women will show lean legs at higher bodyfat percentages (but often carry more fat on their stomachs) in the same way that some women will lose their menstrual cycle at 18% bodyfat and others will still have it at 12% bodyfat.

As a final note about these numbers, I want to repeat something I mentioned above: with a few exceptions mainly aimed at bodybuilders and athletes, the numbers I am presenting isn't so much about telling you what you should do as to give you an idea of what the numbers are. If you're a male at 25% bodyfat, you may be happy just getting to 15% and not have the desire or interest to go any lower. Or you may choose to diet down below 8% because you want to see your ab muscles.

Questions and Answers

Q: Do you think that the trace carbs i.e. starch, etc used as binders in tablets could prevent or disrupt ketosis. For instance I think my ECA stack is hurting my ketosis because of the binders in the tablets. I am at 25mg ephedrine; 200mg caffeine; 81mg aspirin 3x a day.

A: Well, let's think about this for a second. Assuming that your ephedrine pills were 100% starch, that'd be 25 mg of carbohydrate. The caffeine could be 200 mg carbs, the aspirin 81 mg. Even added up that's less than 1 gram of carbohydrates. But, you say, the pills are larger than the active ingredient. True, but even 1000mg capsules are fairly large (they are at the limits of what can be safely swallowed).

The ECA stack you're taking is unlikely to be contributing more than a few hundred mg (and I'm being generous here) of carbs to your diet; nobody is that sensitive to carbs. It generally takes 100 g/day of carbs to keep someone completely out of ketosis although not everyone will show urinary ketones at even 30-50 grams. The few hundred milligrams (let's say maybe a gram) in the pills simply don't matter.

Beyond that, ketosis seems to be fairly irrelevant, as addressed a couple of weeks back in the newsletter. As long as you're losing fat, that's all that matters.

Q: Hi. You've answered my questions in the past, but this time I will asked a much more detailed one. I have lost over 60 lbs in the past 3 years, but I still need to lose more (15-25 lbs). My knees are screwed up with patellar problems so running or any other activity that is tough on the knees are out of the question. Besides losing weight for my knees my doc says I must build up strength in the muscles around the knees and legs/butt. If building strength and losing weight are really at odds with each other what can a person do?

I've been to physical therapy but that only goes so far. When I hit the "sweet spot" of losing about 2 lbs a week I felt I might be losing the lean muscle I am trying so hard to build. What can you recommend?

A: Ok, a couple of things. At least in relatively beginners it is possible to build strength while losing weight. This has to do with the fact that strength gains in beginners tend to be more neurological in nature (the specifics aren't that important). Some studies have even shown an increase in strength during very extreme, protein sparing fast kinds of diets. Again, this is generally in rank beginners. Without knowing more about your current training (i.e. were you lifting weights during the initial weight loss period), I don't know if this applies.

Even there, due to the fact that some aspects of muscular strength are neurological, they can be developed during a diet. You might not make the same magnitude of improvements, but some gains are probably possible. A lot of it depends on your diet. On a moderate caloric deficit with moderate carbs (especially if you put them around training), you may be able to make small gains in strength during your workouts.

Failing that, the best suggestion I can give to you is to alternate phases of active weight/fat loss and active muscle gain/strengthening. If nothing else, this seems to make the diet periods more effective; I feel that most people diet for too long without a break which tends to be physiologically and psychologically problematic. Breaking up diet cycles into more manageable blocks with breaks in-between (during which time you can actively work on strengthening the muscles you need to work on around knees, glutes, etc) simply works better for most. Probably also good as it allows you to stabilize your weight at the new level (see my answer to a question 2 weeks back in the newsletter about the woman who kept rebounding).

So at this point, the first thing you might do is plan on taking 2-4 weeks off of your diet. Bring calories back to maintenance (if you're currently losing 2 lbs/week, this means an addition of about 1000 cal/day which is a lot) and focus on your strength training. You may gain a pound or two (rapid weight loss will be stored muscle glycogen and water) during that time but unless you completely let your eating habits go to pot, you won't gain much more. Having made some strength (and possibly muscle mass) increases, you can go back into active dieting. Aim to maintain your new muscular strength and diet for 4-6 weeks more. Then take 2 weeks off (this is the full diet break discussed in my Guide to Flexible Dieting) and focus on strength gains while maintaining the new weight. Then 4-6 weeks more dieting. You get the idea.

It does stretch out the dieting period but allows you to achieve both goals at the same time.

Q: Excellent information in your newsletters. Will you be giving more specific information on how to manage visceral fat in future issues? Maybe things like which kind of cardio is best, HIT or conventional cardio (i.e. treadmill, etc).

A: To my knowledge, nobody has really examined how different types of activity (either related to intensity or modality) impact on visceral fat. There are the studies which find greater fat loss with interval training relative to steady state cardio and given the extreme sensitivity of visceral fat to catecholamines, along with the hormonal response to intervals, we might expect interval training to work more effectively.

I've even seen it suggested (more by coaches than by research) that excess steady state cardio should be avoided when trying to lose visceral fat; the rationale is that too much cardio can raise cortisol and cortisol is part of the problem with visceral fat in the first place (chronically high cortisol levels tend to promote visceral fat accumulation).

As far as mode of exercise (i.e. treadmill versus bike), I'd be inclined to think that the exercise that lets you work out the most effectively (i.e. some research has found that folks can burn more calories on a treadmill compared other equipment because they are more comfortable with the mechanics of walking) will work the best.