Strength Training Surprises
Exercise is the closest thing there is to a miracle drug,12 and strength training is one of the best kinds of exercise, practically like magic: more healthy and more efficient than most people realize, and a valuable component of fitness and most injury rehabilitation, but not just for the reasons most patients and professionals think. It is the gym-o-centric, load-bearing exercise that mostly guys like to do — bodybuilding, pumping iron, powerlifting. Nearly everyone else ignores strength training, except during occasional New Year’s resolution phases, or when prescribed and/or supervised by a physical therapist.
Please don’t dismiss it! In this article, I will spell out why strength training really matters to ordinary folks, and how to do it.
While I hope anyone who’s ever spent time in a gym will find this helpful, it’s especially written for people with chronic pain and stubborn injuries who are wondering: Where does strength training fit in to a recovery plan?
The best (and least advertised) benefits of strength training
Over the years, I have come to love strength training for fitness and rehabilitation, but not for entirely conventional reasons, some of which are useless or problematic (the classic example is core strengthening, covered below). Fortunately, there are other great reasons to challenge your muscles:
- It’s more efficient and easier than most people realize, requiring less of a commitment. This particularly surprising point is covered in great detail in a separate article. It also has more lasting benefits than most people realize — permanently improved muscle cells!3
- It’s much better for general fitness, health, and weight loss than most people realize, and specifically it can partially replace so-called “cardio” workouts, which are highly repetitive and time-consuming and are a risk for all of the common repetitive strain injuries (RSIs like iliotibial band syndrome, plantar fasciitis, shin splints and several more). For instance, it’s “essential” for people with diabetes, because there’s evidence it controls blood sugar more easily than aerobic workouts (and certainly at least as well).4
- Strength training can be done safely and precisely, particularly aided by machines, so that you can pursue fitness without aggravating existing injuries or risking new ones — a critical rehabilitation advantage that is under-rated or missed entirely by nearly all professionals. Even many personal trainers fail to emphasize this!
Nothing’s perfect, of course. It is possible to hurt yourself or aggravate an existing condition, and I review the caveats below in detail. But, mostly, you “can’t go wrong getting strong.”
A replacement for joint-bashing “cardio”
Contrary to conventional wisdom, strength training is just as good for general fitness and weight loss as aerobic exercise.5 Most people believe — ever since the “aerobics” fad in the 80s — that you have to train the heart to get in shape, and you can only train the heart with cardio, but it’s not true: it is primarily skeletal muscles that adapt to all kinds of exercise, get more metabolically efficient, do more with less oxygen and nutrients, and then demand less from the heart.6
So muscle substantially defines fitness, and therefore considerable fitness can be achieved with strength training alone — and without the drudgery of relentless cardio workouts, and without their injury and re-injury risks. Such workouts — especially running, cycling, and swimming — are brutal on joints and tendons by nature. The risk of repetitive strain injuries is baked right into them! Strength training can keep you in shape, while also giving severely fatigued anatomy a badly needed rest — rest which is the single most important factor in rehabilitation from many of the world’s most common injuries.
By all means, if you are a serious runner, cyclist or swimmer, resume your sport as soon as you can — for the love of it, and for the fitness, because those sports certainly also are good for muscle! But strength training is a valuable and effective substitute because sometimes you just have to take a break to heal.
Doing “cardio” exercise for its own sake may be a worst-case scenario: tediously slaving away on the stationary bike or Stair Master at the gym thinking that you are doing it for your heart, when all you’re really doing is eating up your day and grinding away at your joints, inefficiently training muscles that could be trained more efficiently and more safely by moving over to the weight machines.
I’m not saying cardio is useless — that would be a rather controversial claim, and hard to support with evidence! But I am saying that it has known and obvious risks, and meanwhile strength training is quite under-rated.
Some quick definitions
Strength training is the only method of building muscle mass and strength, and it is the final, logical step in a progression of rehabilitative exercise intensity. Rehabilitation is all about breaking recovery down into “baby steps.” For the severely injured, the first step is the easiest of all possible exercises: simply moving. After that, mobilizing and stretching: slow, rhythmic, gentle tissue challenges. Then comes some endurance training: lower load, higher reps, just to get comfortable with loaded movements again. And — when you are almost completely recovered already — strength training is an ideal final step.
Fun fact: for the first few weeks of regular strength training, and strength gains you experience are mostly due to simply learning how to actually contract the muscle you are exercising (“recruitment”). Only after a few weeks of sustained training do your muscle cells start to get bigger (not more numerous), a process called “hypertrophy.”
How it’s done
The physiological changes associated with strength training occur when you exhaust a muscle within a minute or two.7 If you’re not doing this, you might be doing something worthwhile, but it’s not strength training (or not the most efficient strength training).
When you’re training, you can either count repetitions or just go for as long as you can. I prefer the latter for a variety of reasons, but it’s far more common to count reps. I’ve asked for a second big wall clock in my gym, but the management is puzzled by that: I’m the only one timing my sets. Everyone else is just counting reps and doesn’t care how long the set takes.
There’s a never-ending scientific debate about how to optimize the variables for different types of people and different goals by fine-tuning the number of sets, the length of the break between sets, the number of workouts per week, and so on — although the last of those, frequency, is quite settled down now. (Hint: less than almost everyone else assumes.)
Regardless, there are going to be individual differences for everyone — evidence strongly suggests that some people, for instance, are literally genetically incapable of strength training!8 — but most people will be just fine with the dials set like so:
- only a few key exercises per workout
- 1–2 sets per exercise
- sets separated by a couple of minutes rest
- each set lifting about as much as you can keep in the air for a couple of seconds, or 10–20 slow- to medium-speed repetitions per set
- about a week of rest between workouts (see below)
What’s this about “exhaustion”?
It’s true, you will be tired after strength training — quite whipped! — but “exhaustion” has a more technical meaning in strength training. Exhausting muscle tissue, or taking it to “failure,” is essential for building strength.
Good, consistent exercise form is crucial in strength training not just because it’s safer — it is the simplest, best way of judging both exhaustion and progress. You know you’ve “exhausted” a muscle when you cannot repeat a contraction without losing good form. And exhaustion is exhaustion: it doesn’t matter whether you get there by repeating an easier lift more, or doing a harder one a few times.
If you shake or wobble significantly and can’t stop it, you’ve lost form. If you can’t actually perform the action without squirming into a different position, you’ve lost form. If you can’t do it without bringing in a bunch of other muscles to “pinch-hit,” you’ve lost your form.
And, of course, if you start doing fifteen repetitions instead of just twelve before you lose your form … you know you’re getting stronger!
Exhausting muscles require recovery. How much recovery? How long should you wait before doing the next set?
Less is not less: strength training does not have to be as frequent as you thought!
Most people assume that you have to train muscles at least twice a week to make them stronger, and probably three times per week.
Believe it or not, scientists are actually pretty much unanimous in their agreement about this. In the last twenty years of research, there is barely a single dissenting note! Strange, I know. Exercise science is usually more controversial.
A lot of people are skeptical about this and should be. But I have an entire article devoted to summarizing the research. If you doubt my word, please check for yourself: nine key scientific papers between 1988 and 2007 are cited, all showing clear evidence that most people can probably reduce their training frequency with little or no change in result. See Strength Training Frequency.
Once or twice per week for a given muscle group is adequate for most people, and three times per week definitely has a diminishing returns problem. Depending on the variables, some people could literally triple their gym time and effort, from 1 to 3 workouts per week, and get no additional benefit. Others might get some benefit, but minimal.
Such time savings are not trivial. Particularly for patients doing strength training only because it’s important to rehab, the reduced commission is truly important — it could easily mean the difference between doing it and not doing it. This is a guess, but it may also be even more appropriate — safer — for people with injuries to take more time for recovery between workouts.
Seriously, hire a trainer
If you are serious about using strength training to bulk up or to complete a rehabilitation process, you should definitely hire a personal trainer and/or a physiotherapist. Not only is it obviously safer to use heavy weights with guidance, but you will also simply get better results.9
However, do beware of trainers who push too hard and think that you need more than one workout per week.
Bored with tedious strength training prescription? You’re not alone!
Is this you? Your physiotherapist has prescribed a long list of therapeutic exercises that you are supposed to do frequently.
Almost immediately, it’s boring — and difficult. Many of them are what I call “ear wiggling” exercises: it’s hard to contract the muscles that you are supposed to contract. Either you can hardly do the exercise at all, or you can do it but the muscles are small, and it’s weird and frustrating how quickly such a small movement becomes totally exhausting.
But it’s supposed to be hard, you rationalize. That must be the point. The fact that you can just barely lift that 2-pound weight ten times must mean you really need this.
So you keep at it.
For a while. But the problem doesn’t really get a lot better, the exercises never really seem to get much easier, and in fact — honestly — you actually feel kind of gross after most sessions, sometimes even downright worse. And there are so many of them. And there’s no end in sight.
It’s like a life sentence: it seems like you are supposed to do these exercises practically forever, especially because you’re not really getting better …
Why strength training as rehab often fails
Rehabilitative strength training probably does aid rehabilitation in many cases. For instance, two papers have shown that both strength and endurance training were effective for treating neck pain,1011 which probably proves at least this much: almost any activity is probably better than no activity. Another pair of studies from 2008 and 2010 both showed that painful shoulder muscles respond well to strength training, getting both stronger and less painful.1213
Nevertheless, physiotherapeutic strength training is probably risky. I know and hear from an awful lot of people who are still in pain, despite doing lots of this strength-o-centric rehab. What could account for this? There are at least three significant problems I can think of …
It’s not really relevant. There is a kind of simplistic mentality behind the prescription of strength training exercises — it tends to come from a bull-headed “this part isn’t working so let’s make it work, make it tougher” idea. While I appreciate a certain amount of “use it or lose it,” it’s also kind of like the cause of a headache is not the absence of Aspirin. Strength training probably isn’t the magical missing ingredient when someone is in chronic pain. Almost no one gets into much painful trouble in the first place because they were weak. Weakness is not, by and large, a cause of pain and injury.14
It’s tedious. In my experience, the huge majority of people simply cannot stick to a no-end-in-sight regimen of fiddly little strength training exercises. When physiotherapists prescribe large batches of these things, they are simply not coming to terms with the realities of human psychology. In medical science, this is the difference between “efficacy” and “effectiveness”: how things work in theory versus practice.15
Too much, too soon. There are some ways that strength training can backfire, some that are inevitable, but most are easily avoided by staying in the Goldilocks zone … and encountered regularly when you don’t, which happens all too often, especially due to overzealous coaching and encouragement from personal trainers and physical therapists. I will review many of the specific ways that things can go wrong below, but the point here is just that it can go wrong, and it may not be an overt backfire: often it just subtly sabotages progress, prevents it from doing any real good.
And so I’ve known many clients and readers in various stages of disillusionment about their physiotherapy exercises. I almost never have to tell them to stop — most of them already have — just to stop feeling bad about it.
Finding the right balance between too much and too little is a theme that runs through all my articles about therapeutic exercise.
Strengthening your core to no avail!
Probably the ultimate example of therapeutically irrelevant strength training is trying to treat/prevent back pain by strengthening your “core” — muscles around the pelvis, lower back, and abdomen.
Your back hurts. You are generally healthy but, dammit, your back really hurts — and why is that, anyway? You’re generally fit. You take care of yourself. You can’t possibly be a weakling.
You don’t trust doctors with your back (which is smart, you shouldn’t16), and in fact, you’re not that keen on seeking help for this kind of thing in general. You’re independent, competent, so you take matters into your own hands. Back hurts? Exercise it.
You’ve heard lots of about core stability. That has got to be important for your back. “Core stability” just sounds so good — cores should be stable, right? So it’s off to the gym.
But your results range from underwhelming17 to making a bad situation worse. A few of you will get good results. But several will also end up in pain thinking “What was I thinking?” And most simply won’t get any clear results at well. You will feel exhausted, old, vulnerable … discouraged.18
“You can’t go wrong getting strong” … or can you? The hazards of strength training
Many independent, motivated people in pain will go to the gym hoping to train their pain away, only to discover that it isn’t quite that easy. Some succeed, others fail. Some of them actually get hurt instead.
Maybe they heard that “you can’t go wrong getting strong.” The idea that strengthening is almost perfectly risk-free is a surprisingly popular, naive concept in rehab and chronic pain treatment. There’s certainly truth in it, probably more than just a kernel but I think it’s wrong a little too often for comfort. That clever rhyme may not be a great thing to tell a lot of patients.
Most risks of strength training go away if you just add one critical caveat to that expression: “You can’t go wrong getting strong … with good load management.” Keep the intensity in the Goldilocks zone, no big spikes in intensity, don’t rush it, and most of what can go wrong probably won’t.
There are certainly some pathologies where resistance training is just a bad idea no matter what, but those are mostly irrelevant in the context of typical musculoskeletal medicine. When it comes to working with “aches n pains,” there’s is almost no such thing as “going wrong” with strength training if you don’t go too far, too fast. But if you do? With poor load management, you can go wrong strength training quite easily. And of course, a lot of people do overdo it, for many reasons.
And so we have a theory versus practice problem here that probably accounts for a wide range of opinions on this:19 if you assume sensible dosing and competent coaching, then it really is hard to go wrong; if you focus on the prevalence of amateurish training “in the wild,” then going wrong is all too likely.
Exactly what can go wrong with strength training
This is a list of specific examples of how strengthening can go significantly wrong without exercising extra caution, which is unfortunately rare in practice.
- Direct, simple injury has to be at the top of this list. It’s not as common as people fear — powerlifting is amazingly safe for backs, for instance — but it’s not exactly rare either. Bad things can happen when you are moving around heavy things. But this list is more about the non-obvious possibilities …
- Misdiagnosis is a large category of ways that strength training can go wrong. Some problems that appear to be “simple” musculoskeletal problems, like back pain, actually have medical causes, some of them ominous, such as pain caused by a tumor, or a drug side effect. The failure to diagnose such things correctly can lead to prescriptions of completely ineffective or harmful strength training. Here are just a few key examples, and there are probably dozens more (because there are so many surprising ways to hurt:
- While training to look the part of Spartacus, actor Andy Whitfield pushed through a lot of back pain, assuming it was a normal reaction to the intense training, but it was actually cancer that killed him a few months later. Such scary causes of back pain (and other pain) are rare, but not rare enough — the possibility should not be ignored. A benign back tumor tormented a personal friend of mine, pressing on a nerve, for about five years before it was diagnosed. During that time, he tried strength training a couple of times, with predictable, miserable results … and then he was decisively cured by surgery.
- Another “tumor”: One of my readers had runner’s knee (iliotibial band syndrome) caused by a benign cyst stuck under his IT band like a rock in a shoe: good luck treating that with strength! All you’re going to do is piss it off.
- Hypermobility (hypermobility spectrum disorders and Ehlers–Danlos syndrome) is usually caused by complex genetic defects that have poorly understood effects on muscle and connective tissue. Patients are often chronically sore and suffer from a parade of miscellaneous “unrelated” musculoskeletal problems that can go undiagnosed for years, even a lifetime. It’s possible that strength training is doomed to backfire with these patients. Or perhaps they need strength training more than anyone? But only with much greater caution than average, and probably much more than they are likely to suspect the need for.
- Chronic fatigue syndrome (unexplained fatigue, also often overlapping with chronic pain, which is why I’m including it here): these patients may seem like ideal candidates for exercise therapy, but if the cause of the fatigue is myalgic encephalomyelitis — a nasty infectious neurological disease that routinely evades diagnosis — exercising can backfire severely,20 and might even make the condition permanently worse.21
- Facioscapulohumeral muscular dystrophy (FSHD) is a common and usually fairly mild form of muscular dystrophy that can cause only mild symptoms for decades, including and especially weakness, soreness, and chronic musculoskeletal complaints … exactly the kind of trouble for which strengthening is often prescribed! And it might help mitigate the problem, but patients will certainly be much more vulnerable to exercise overdose, and of course, their problems cannot actually be solved by strength training.
- Frozen shoulder can get severely exacerbated by any attempt at strength training, no matter how careful. This condition can even flare up badly even just with a range of motion exercises.
- Neuropathies — pain caused by trouble with nerve tissue — of all kinds can be seriously exacerbated by resistance training. It’s important to note that these conditions are often surprisingly subtle and undiagnosed, but misdiagnosis probably isn’t the main problem: it’s underestimating their vulnerability to exercise therapy in general and strength training in particular.
- Chronic Achilles tendinopathy is prone to rupture and can be triggered by rehabilitative strength training, especially rapid loading (eg plyometrics). While carefully managed eccentric loading might be therapeutic, it’s not totally clear, and exactly how much load these tendons can handle without breaking is largely unknowable.
- Repetitive strain injuries can occur because of natural vulnerability to relatively normal loading — not “overuse” — and anything less than extraordinary caution with dosing might make it worse. Patellofemoral pain is the canonical example: that joint is naturally biomechanically extreme and can get overloaded even with very average use.
- Sensitization often involves greatly reduced load tolerance … so much so that even cautious resistance training is ineffective at least, hazardous at worst. Since sensitization is probably a factor in most stubborn injuries, this is highly relevant to a lot of rehabs, especially for the worst cases. Chronic widespread pain is related to sensitization (lots of overlap), may eventually benefit from building their strength, but often have such poor load tolerance that they just can’t handle resistance training (at first for sure, maybe never).
- Anxiety and hypervigilance. Some people are indoctrinated to believe that the point of strength training is to fix weakness (especially “core” weakness) that makes them vulnerable to injury. Belief in fragility can become a major factor in future episodes of pain, especially back pain, which is notoriously sensitive to such anxieties.22 It can also lead to a great deal of wasting time if people focus on training obscure muscles far beyond their functional needs.
- Trigger point exacerbation. The sore spots that most of us often develop in soft tissue are poorly understood, but they probably involve some vulnerability to physical stress. They may flare up if you’re not careful, even if they respond well to cautious progressive training. Anecdotally, I think quite a few “injuries” at the gym are not muscle strains (tears) but simply aggravated trigger points, which can be so acute that they feel like injuries.
Now back to the good news
Yes, there is good news! Strength training can be useful, and it can be done safely.
You should do strength training when you have already paid your dues doing easier work first. You should do it to cover that last, crucial step from “recovered” to “better than ever.” You should do it to test your tissues, to reveal remaining vulnerability, to demonstrate to yourself that you really are better. When you are ready for it, strength training is a powerful way of demanding the highest possible function from your tissues, the most potent way of “using it” instead of “losing it.” The physiological effects are significant and numerous:
- blood flow is increased far more than any massage could ever do, capillaries open up wide, the entire system mobilizes resources to supply hungry muscles with oxygen and nutrients
- metabolic waste products are produced and washed away at a prodigious rate, probably including old stale ones still lingering in the dregs of trigger points that you mostly (but not entirely) got rid of in earlier stages of recovery
- coordination and neurological function improves with every workout as you “learn” how to actually recruit a respectable number of muscle fibers, which is responsible for most early strength gains
- rusty inhibitory and excitatory reflexes are exercised, normalized, balanced, which probably provides an injury prevention benefit
And, of course, if you do enough of it you may even get some vanity benefits, hypertrophied muscle cells, “big guns,” a stomach with speed bumps. Wouldn’t that be nice?
All of this is just great … when you’re ready for it.
The psychological edge
Some people can probably benefit from the gym sooner than others, even in spite of trigger points. For a lot of people, especially guys, challenging themselves with weights has huge psychological and emotional benefits — so great that, for a certain type of person, they can outweigh the risks, even when muscles may not be quite ready for strength training.
The same can be true for anyone who has gone through a rational, well-managed rehabilitation process. If you are impatient, if you like endorphins, if you have already tested yourself with endurance training and do not feel too held back by trigger points, then you might be able to exploit strength training sooner — before other people would be considered “ready.”
Strength training can “blast through” the limitations of trigger points in such cases. I’ve seen it a few times, even experienced it occasionally. Obviously, you should not try to do this without being alert for warning signs.
Not just the gym
Of course, some people don’t like gyms. I’m one of them, actually — or used to be, anyway. You should consider trying to overcome gym shyness because (a) the people there are probably nicer than you think, (b) strength training is fairly efficient and you probably don’t need to spend as much time there as you fear, and (c) the precision and control of universal gym equipment has many advantages.
Nevertheless, there are some excellent, creative alternatives to gym training. Your own body weight can be more than adequate for strength training in many large muscle groups. Slow deep knee bends, push-ups, chin-ups, and abdominal roll-ups are all good examples of body-weight-only exercises that many people cannot do many of — good places to start strength training without gym equipment.
However, it must be said that a thorough strength training program simply cannot be done without at least some apparatus. A small investment in a few barbells and exercise bands or tubing (large, colorful elastic bands or tubes) allows for an almost infinite number of strength training options.
Can strength training prevent overuse injuries like runner’s knee?
Repetitive strain injuries like plantar fasciitis and iliotibial band syndrome (runner’s knee) are often seen as a price that active people pay for being weak in some way. Although this has always been a popular view, it’s been given new life since the early 2000s by a lot of hype about hip weakness specifically, which supposedly causes runner’s knee (and maybe other overuse injuries in the lower body). If it’s true, then surely strength training the hips can prevent the runner’s knee? Unfortunately, this is just a pet theory that got out of hand and still isn’t supported by any credible evidence.23
A 2014 meta-analysis is the best reference available to support a more general claim that resistance training will prevent overuse injuries.24 Unfortunately, “the best” is not very good: the authors’ conclusion about injury prevention is based on data from just four studies of questionable/limited relevance …25 and there is definitely some contrary evidence as well.26
Strengthening might prevent some overuse injuries, but that’s an untested hypothesis, and Lauersen et al simply do not provide meaningful support for it—not even remotely. There are all kinds of other reasons to train your muscles. Use those reasons. You don’t need this one.
On the bright side, strength training probably can reduce the risk of tearing a muscle, an extremely common sports injury (muscle strains). It makes more sense, and there’s some evidence supporting that.27
Muscle knots are significantly involved in almost every injury or pain problem. And strength training, by definition, demands exactly the worst possible conditions for muscle knots, namely severe muscle fatigue — so please be careful when strength training. If it aggravates your symptoms or leaves you feeling drained … go back to endurance training!
But strength training is an important final step in rehabilitation for those who are ready: either when trigger points are mostly under control, or perhaps a little earlier for those who really enjoy hard exercise.