From the Ivory Tower to the Iron Trenches

Peri-workout recovery supplement (RS) drinks, which are combinations of protein and/or (essential) amino acids, carbohydrates (often “high-tech”), and various other bells-and-whistles ingredients consumed before, during, and after resistance exercise, have only made a big splash on the supplement scene in recent years(1, 2).  Older and more crusty vets like myself, however, know that they have been around much, much longer. In fact, IFBB Pro Milos “the Mind” Sarcev may be the most famous individual for feeding his athletes carbohydrate and protein mixtures during training. In turn, John Meadow's clients, like IFBB Pro and elitefts™ athlete Mark Dugdale, attribute a large part of their ability to survive John’s workouts to RS products.

I have personally been toying with various concoctions for 15 years or so. At one point, I had even worked up to thick n’ hearty 2,000-calorie intra-workout drink. (Yes, that’s not a typo, but it also not a least for your first go at a peri-workout RS.) I picked up this idea from a book by Thomas Fahey, EdD (3) outlining what he then called “Insulin Loading (4).” Basically, this meant that you consumed a  2,000-calorie liquid meal (150 grams of protein) intermittently over a two-hour workout (4, 5).  (I’ll talk a bit more on super-sized RS in the last installment of this article series.)

He says, She says: Do Peri-Workout Supplements Really Work?

Despite their popularity, which I think we can say has past the novelty phase (1, 6), as well as the empirical effectiveness of peri-workout RS opined by many bodybuilders, the science on the matter of nutrient timing is somewhat mixed. While some researchers are devoutly in favor (7), others are less supportive of peri-workout RS (8, 9).  Truth be told, I have even spoken with several bodybuilders who haven’t perceived an improvement in recovery, a reduction in muscle soreness, and/or enhanced gains as a result of slugging down protein shakes while training. (I have noticed that this lack of effect is usually paired with complaints of gastric distress and/or lack of hunger). RS proponents may tell the lab coat naysayers that “you can prove anything if you find the right study.” Some may even build a straw man argument by saying, “when you get those lab rats squatting five plates, come talk to me…”

This matter is what researchers would call external validity. In other words, how far can you extend the findings of a given study beyond its specifics? We’re talking about variables like the RS timing relative to other meals, the subject's training status, and the caloric content and macro-/micro-nutrient composition of the RS. Any or all of these details may make a given study either quite fitting or completely irrelevant for a given bodybuilder. If you look closely at a study, it’s sometimes easy to see the limits of external validity. For example, did the subjects performing the resistance exercise walk on two legs or crawl about in cages on all fours? Sometimes, however, there’s a bit more to unlocking the puzzle of mixed findings in a body of literature (which is what I hope to do here, in part). I also hope this article series provides some insight as to how you can critically analyze a research study.

Integrative Bodybuilding: Tying It All Together

While external validity generally limits application, most experiments (even if not “perfect” emulations of real life), lend themselves to an integrative approach. In other words, you can glean useful lab information and integrate it into the gym conditions during real workouts. This is what I call Integrative Bodybuilding. For example, this might mean introducing more ingredients, which are ideally well-supported by separate experiments, in your RS than what would typically be tested in a single research study. Paralysis by over-analysis and sticking only to what’s been shown specifically in research studies isn't renowned for packing on gobs of muscle. That being said, and with placebo effects aside, which can be quite “steroid-like” actually (10), I’d like to tackle a few things in this article series:

Part 1 (this article): Shine some light on why focusing on acute (single bout) experiments versus training studies might contribute to the conflicting results and opinions regarding peri-workout RS. I’ll focus here on supplement timing and cortisol. (Henceforth known as “the sneaky bastard”).

Part 2: Follow-up on Part One and provide some insight as to why being trained essentially makes you categorically different than a newbie test subject.

Part 3: Combine what the research does tell us with my experience (personally and with clients), and lay down some real world, in-the-trenches approaches to making a peri-workout RS an effective tool for recovery, muscle, and strength gains.

Timing: Intra-Workout Is Post-workout

“Post-workout” for a research study may mean that you have to time your RS by taking it intra-workout. To keep it simple (for various methodological reasons), it's fairly common to examine post-workout RS effects on muscle metabolism after exercising only a relatively small muscle mass. For example, a single muscle, a muscle group (like the quadriceps femoris), or maybe an isolated set of muscles like the quads and hamstrings (11-17). In contrast, a typical bodybuilding workout targets several muscles and often takes a bit longer than a research exercise bout. For instance, you might start with chest training in order to prioritize it (18), and then you may move to delts, triceps, abdominal work, and possibly some cardio. This can easily mean over an hour or more has lapsed after pec training—an hour before you slug down your “post-workout” RS. Add this to the slowing of absorption due to gastric delay (19, 20), and the time before your chest muscles experience the nutrient and hormonal effects of the RS can be 90 minutes or more. Well, so much for taking that recovery supplement immediately “post-workout,” at least when it comes to the chest—your “prioritized” muscle group.

The “big deal” here is that delaying carbohydrate (21) and/or protein consumption (7, 22, 23) after training can dramatically reduce how well an RS elevates glycogen and protein synthesis. In one weight training study where subjects were required to wait two hours after exercise to have their RS, they missed out entirely on the muscle growth enjoyed by the group that consumed just a modest RS immediately post-workout (~100 calories with 10 grams of protein) (24).

Bottom Line: Intra-Workout is “post-workout,” especially for the first muscles/muscle groups trained in a typical bodybuilding workout.

Laboratory vs. The Long-Haul: Cortisol, You Sneaky Bast*#d!

Training progress takes time. Progress takes repeated brutal efforts with consistent nutrition and adequate recovery over the course of months and years. The temporal window through which researchers peer when using small muscle mass acute exercise tests (often using untrained subjects—which I’ll address in Part 2) may not predict long haul gains (for various, fairly obvious reasons such as uncontrolled dietary changes, level of training effort, general variability among trainees (25), etc.). One dastardly culprit clouding the picture may also be cortisol (the “sneaky bastard”), a catabolic/proteolytic stress hormone (26) antagonistic to the anabolic effects of insulin and growth hormone (27-29) that also gets released during exercise simply for fuel handling (carb, fat, and protein oxidation).

The harder you push yourself, the heavier the load (30). Also, the more work you do in a given amount of time (31-33), the greater the cortisol release. This means that a brutal 90-minute training session while blasting Iron Maiden in your garage gym just might elicit a bit more cortisol release than a 45- to 60-minute workout guided by an anonymous, lab coat-donning graduate student counting your reps in tempo with a metronome. On the other hand, research (and common sense) suggests that keeping cortisol levels under control, both post-exercise—which actually occurs during the course of positive training adaptation (34)—and in general (“resting levels”), may be vitally associated with training progress (35, 36). In other words, living with high stress doesn’t help you grow.

Unfortunately, using acute post-workout cortisol release to gauge how an RS impacts recovery may be complicated by the fact that the macronutrient composition of the RS itself can cause cortisol variation. Consuming an extremely high protein meal or a protein-only meal raises cortisol (37, 38), whereas consuming carbs will reduce blood cortisol levels (38, 39). Not surprisingly, post-resistance exercise RS blends elevate (31) or have no effect (33, 40) on cortisol, while intra-RS also had no effect(41) and reduced cortisol post-workout (42). In the context of this mish-mash of results, it seems that the uncertainty about whether carbohydrates are a worthwhile addition to peri-workout RS (8, 9) rests primarily with a single acute study that lacked cortisol measurements. However, it demonstrated that adding 50 grams of carbohydrates to 25 grams of protein to a post-exercise RS had no effect on muscle protein breakdown or synthesis during the first three hours post-exercise(43).

More revealing to me, however, is a training study showing that repeated consumption of an intra-workout RS that reduces cortisol during and after exercise (42) also translates into less muscle breakdown (44). Most importantly, it translates into greater muscle growth, week by week. In fact, the muscle gains in this study correlated with the attenuation of the cortisol response over the course of training (45). In other words, the less cortisol was elevated, the better the subjects grew. The difficulty in connecting cortisol elevations with an immediate impact on protein metabolism (i.e., when the experimental design only includes short-term measurements) may lie in cortisol’s relatively slow proteolytic effects, which can take hours to manifest (46) and be imperceptible when using the protein tracer methodology typically employed to measure metabolism in acute exercise studies (27, 47, 48).

Still, it is true that other research has shown that resting cortisol levels many hours after your last training session predict muscle fiber growth (49) and strength performance (50) over the course of long periods of training. In one study where a carb-based RS essentially eliminated exercise-induced cortisol release (34, 51), most of the variability in muscle fiber growth among subjects could be explained simply by “cortisol control.”

This is not to say that training should be easy just so that you can keep “the sneaky bastard” at bay. On the contrary, in a recent resistance training experiment (no RS was given), generating greater post-workout cortisol (testosterone and IGF-1 responses were statistically irrelevant) meant better muscle growth (52). This was likely because, as I mentioned above, the harder you train, the greater the cortisol release. On the other hand, the subjects who grew best were obviously also able to recover between training session.

Bottom Line: I’ll tell you what you already knew. Training harder releases more cortisol, but you’ve got to train hard to get big. Recovery must take place as well (meaning lower cortisol levels all around), and a peri-workout recovery supplement is one way to do this. My personal wish would also be to see a widening of the research aperture in the future—in order to further pinpoint the acute and round-the-clock impact of cortisol on the hypertrophic muscle “remodeling” process.

In Part 2 we’ll continue to add some context to the peri-workout RS research literature. As an extraterrestrial astrobiologist comparing you, the reader, to the average citizen might surmise simply from ogling your muscle mass, there are several important categorical differences between highly trained individuals and the previously untrained (and “science” knows it, too).


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