In biology, it’s rare to find an instance where more is always better. Biological systems respond in dose-response relationships. More is better — to a point. Once you get past that ideal range, more is worse. You can visualize this as an inverted U-shaped graph, with the ideal range falling into a nice hump between the two extremes. Although this relationship originally developed to describe the relation between psychological arousal and performance, it fits strength training data perfectly.
An inadequate stimulus doesn’t trigger any response. An extreme stimulus overwhelms the organism, causing more harm than good. The hump, a moderate stimulus, is where you want to be. Too little won’t do anything and too much is harmful.
Extremism captures the thought process of many exercise fanatics. If some is good, more must be better. This probably isn’t a conscious thought process in most people; I’m convinced that, much like overeating, exercise addiction hides beneath our rational minds, and that allegedly rational mind later rationalizes our actions.
You can tell people over and over that doing 50 sets for biceps isn’t helping you grow. You can tell them that sprinting to exhaustion every day won’t help them lose weight. You can tell them that cleans with wrist-wrecking form — for time — have no real benefits. Tickle the brain chemistry with the right combo of exercise and social interactions and none of that matters. The endorphin high might as well be heroin; the social gathering, a hit of coke. This is why overweight housewives chain themselves to the treadmill and never see any changes. This is why stupid Crossfit WODs happen. Suffering and pain become the quintessence of the addiction.
Pain means productive. Pain means neurochemical reward. Pain means reinforcement from the herd.
If the connection to the facts aren’t made in more subtle ways, you might as well be telling a crackhead that drugs are bad for him and hoping he’ll quit since you’ve told him the truth. People follow feelings, not rational self-interest.
Exercise in low to moderate amounts reduces inflammation. Exercise in moderate amounts is healthy and anti-inflammatory. Training to exhaustion, to the point of muscle damage, triggers a much larger inflammatory event, and this can cause you to feel bad (sickness behavior) and reduce performance (central fatigue).
Why the discrepancy? Healthy people are just that: normal folks, sedentary and untrained, coming to the gym and activating all that dormant biology. All those genes wake up and start working within their designed parameters. Moderate amounts of stimulus, including discomfort, are healthy. But the dose-response effect matters: what’s good in moderation becomes bad in excess.
I was prompted to write this post by a comment reply I left a few weeks back, and then by a fortuitous paper which came to my attention a week or so back.
(And as a late addition, this review came out just yesterday, which I haven’t had time to peruse but seems to lead right down the same street.)
What do these two things have in common? They discuss the need for causing muscular damage when training for muscle growth and, to a lesser extent, strength. The premise: muscle damage isn’t required for growth or strength gains.
I discussed this topic in all its Labcoat glory in my older article on DOMS and in Maximum Muscle. The summary, for those not willing to risk the aneurysm, is that muscle damage is incidental to muscle growth. DOMS (muscle soreness occurring post-training) is incidental to both damage and growth stimulus.
For years, we’ve been told that our goal is to ‘break down the muscle’ so it will grow back stronger. There’s a kernel of truth in that statement. Hypertrophy is work-induced — that is, you make the muscle Do Something, which stresses both force- and energy-producing structures in the muscle fibers, and in response those fibers get larger. The parameters for that Something are still an amorphous mass of vaguery, but we know some important points:
- Intensity must be above a certain value, or else the stimulus isn’t strong enough to do anything. Usual values fall from 60% on up to 100% (or more, if using eccentric contractions).
- Intensity should be less than our maximum (less than our 1RM), or else we can’t do enough work to create a stimulus. A weight producing 95% of a muscle’s max tension is heavy enough, but you may not be able to eke out enough reps to matter.
- Work (measured as volume, tonnage, or time-under-tension) must be ‘sufficient’ to cause growth; it’s not enough to lift a heavy weight — you have to lift it enough times to matter.
- Fatigue, in the sense of immediate inability to contract (what you’d call concentric muscular failure), affects the activation of muscle fibers and probably contributes to the growth response by preferentially training the hypertrophy-prone fibers.
- Because of that fatigue effect, the intensity variable might be fudge-able if the mechanical work is sufficiently difficult — as in the case of longer sets to failure and repeated sets with brief rest intervals.
The formula’s pretty simple. Lift moderately heavy weights for a moderate amount of moderate-to-hard reps. Intensity plus tonnage plus fatigue yields bigger muscles.
Heavy weights are self-explanatory. ‘Power training’ has been the prescription for size since olden days, relying on low-rep sets of heavy weights mixed with high-rep, but still heavy, work. Volume, tonnage, and time-under-tension are all ways of describing how much work is done. Volume is the ultimate determinant of growth, as hypertrophy is work-induced, as long as the work is heavy-enough. Bodybuilding has long favored this mode of training, promoting multiple sets and exercises for high(er) reps.
Indicators of muscle damage, on the other hand? They just don’t rate. There’s no evidence whatsoever, besides the fact that DOMS happens with resistance training, to support the idea that we have to damage our muscles. The popular idea of trashing a muscle, putting it through strenuous, exhausting workouts, has no basis at all.
That’s what this study shows us, confirming that hypothesis along with other work. The soreness and indicators of muscle damage that accompany a new workout program are symptoms of that unfamiliar stress. Your muscles aren’t used to moving weights around, and they take a beating for it. But even after they adapt, you can continue to get bigger and stronger. No damage required.
There is undoubtedly a fatigue component to muscle growth, and this fatigue component ties in to the stimulus of eccentric contractions. There’s a difference in four sets of 10 with one-minute rest breaks, and five minute rest breaks. There’s a difference in using your 10RM and using a weight that lets you complete all four sets without so much as a grunt. But fatigue is not the same as damage; damage is a function of training through fatigue.
I’m not talking about metabolic glycogen-depleting AMPK-activating fatigue. This has to do with what’s called excitation-contraction coupling, which uses calcium ions (Ca++) to set off a cascade that winds up with a contraction. During a fatiguing contraction, ATP levels are insufficient to disengage myosin and actin links that form as the muscle ‘pulls itself tight’. The proteins stiffen and Ca++ builds up in the cell. That fiber’s now out of commission, and is a biochemical mess.
This acute contractile-protein fatigue doesn’t immediately affect energy reserves, but it does cause that feeling of weakness you get when you really trash a muscle with sets-to-failure or very short rest breaks. There’s also evidence of a link between this kind of eccentric fatigue and Almighty Growth Factor Supreme, MGF.
Pushing to (and through) fatigue is, again, a common aspect of traditional bodybuilding programs, and for good reason. Local, acute fatigue in a working muscle — within reason — almost cheats the nervous system, tricking it into stressing different ranges of muscle fibers and (possibly) increasing the expression of powerful growth factors.
Because of this complication, it’s important to realize that recruiting a muscle fiber — say with a very heavy weight that causes maximum fiber recruitment from the first rep — isn’t necessarily the same as training it. To train a set of fibers, you need variable rep ranges and some degree of near-failure effort (I’ll leave the bickering over ‘near failure’ and ‘omg momentary ability’ to Cyberpump. Remember Cyberpump? Man those were fun days.)
But real damage to the muscle? Nah. Damage is overrated, and based on older animal models of muscle adaptation. Damage can and does happen in human muscles, but it’s not desirable — we see it happen in distance runners and other long-distance athletes, and the results aren’t pretty. Inflammatory cytokines come out to play, and there’s some evidence that this can cause fiber necrosis (although this may only be in those animal models). From the authors of this study:
From an engineering perspective, damage as a necessary precursor for restructuring would seem to be a poor ‘design feature’, requiring unnecessary vulnerability (i.e. sarcolemma damage, soreness and weakness) in response to a requirement for additional strength. It seems that a need for added strength to be coupled to a requirement of damage-induced diminished strength would certainly be avoided by natural selection if possible. Indeed, during chronic resistance training, whether an athlete experiences muscle soreness and damage at the onset of training would seem to have no impact whatsoever when training continues uninterrupted over months or years. The addition of muscle size and strength that persists after years of continuous training must be completely uncoupled from any initial damaging bout of muscle damage months or years prior.
Muscle damage is most assuredly not helping you get bigger, stronger muscles. The good news is that most sane strength-training programs aren’t going to push you to that point. Damage is the kind of thing you’ll see happening in the frat-boy workouts of EZ-bar curl drop-sets, where they start with like four 10s on each side of the bar and do back-heaving sets to failure while the other guy takes a plate off at each stopping point. You might get some of those in those step classes where they use the weights and have you doing high squats and that kind of mess. Anything that takes strength training and treats it like endurance work, cheering you on to ‘push through the burn’, is probably doing more harm than good.
For our practical go-to-the-gym needs, the truth is that growth stimulus happens on a continuum, and anything you do that’s in that equilibrium zone of intensity, volume, and fatigue is going to stimulate some kind of positive response. Create a little stress and you get a small response. Do more, and you get a bigger response. Train so much that you kill off half your muscle fibers and get a case of rhabdo, and you’re well into the Lethal Dose segment of the inverted-U curve.
There are many ways to maximize the net growth stimulus by futzing with each of those variables — which is why Oly lifters can have huge traps and thighs while rarely going over 5-6 reps, and curl-jockeys can actually wind up with pretty big arms by doing nothing but multiple sets of 12-15. Regardless of your favored method, the goal was put best by Lee Haney: stimulate, don’t annihilate.
Growth occurs when the net work is enough to create the required stimulus, and fatigue which results from that work may help that along — in other words, get tired from using heavy weights and hard-ish sets — but as this study and others like it show, fatigue-induced damage, resulting from excruciating exhaustion-by-volume, just isn’t necessary. Fatigue is good in moderation. Training to brutal, messy exhaustion isn’t so good.
The moral of the story: don’t train like a frat-boy.