While I’m not as beat up as many seasoned lifters, I’ve done my share of damage.
Both shoulders have suffered partial tears in the rotator-cuff muscles and are full of scar tissue, which I blame on my early days as a bench-bro (along with long arms and a lightly-built frame). I’ve torn an adductor muscle in my left leg and, less than a year later, I tore the quad of my right leg while preparing for a powerlifting meet.
It’s always been painful to bench and now I have to keep a close eye on both legs, so training heavy isn’t always so fun. You’d probably expect that somebody in my position doesn’t need to train heavy and certainly doesn’t need to train often. The reasonable conclusion is that since lifting heavy hurts and entails some risk of injury, that I’d want to be even more conservative and do it less often.
If you recall from the introduction, I mentioned that, while lifting every day, I noticed my joints feeling better. That goes against the grain, but I’ve got a good explanation for it: the body is less a machine with a limited fuel supply and more an ecosystem that responds to cultivation.
When I first took the plunge, I was paranoid about getting hurt again, but at that point I had nothing else to lose. I could either train how I wanted ― heavy and with the big lifts ― or I’d just have to quit and take up stamp collecting.
As the days and weeks went on, I noticed something. Not only was I not getting hurt, but all the squatting felt like it was greasing the rails. The old injuries, which normally ached and made me very aware that I was bothering them, started griping less and less.
They never became painless, but I’d not expect that. It was more like they retreated into a background noise of dull ache, sometimes irritating, but never once did I feel like a catastrophic blow-out was imminent.
At that point my interest was piqued, and I kept coming back to a post John Broz made on the Bodybuilding.com forums:
NOT training everyday leads to more injuries! I F you train everyday then your entire body is fatigued. Muscles, tendons, cartilage, ligaments, etc. When you train every other day, then the muscles and avascular tissues don’t recover at the same pace.
What happens is the muscles become fresh and recover but all the connective tissue is NOT. When the additional stress put on these weakened tissues (that never really got a chance to recover) by fresh muscles = injury. Lifting everyday keeps everything in a state that is equal and consistent within the system. A balance or harmony within. The fatigued muscles can’t contract enough to harm the other tissues. The weak link moves from body part to body part, and in a sense is not letting the other parts max so that’s when they are resting! 66
It made sense, at least from what I was experiencing and from stories I began hearing from others who found a similar “joint greasing” effect, and that’s when I discovered the
work of Michael Kjaer at the University of Copenhagen in Denmark.67
In the “mechanical” view, training under heavy loads causes damage and carries some non-zero risk of injury, so by extension, reducing training frequency automatically lowers that risk. It’s a simple one-to-one correlation between work done and risk, which entirely depends on the machine metaphor. That reasoning simply didn’t fit with what I found. blood, but relative to their muscles it’s a paltry supply.
Muscles have dibs on a huge share of blood, and when you exercise that share increases by some 20 times. That blood flow delivers nutrients and clears away waste products.
Tendons don’t get that treatment. Kjaer notes that an inactive tendon receives somewhere around 1-3% of the blood flow as the nearby muscle. It’s only during exercise that the tendon sees an increase in blood flow, but even then the increase is remarkably low compared to the adjoining muscle.
You might wonder what difference this makes, although folk-theories of biology hint at how important blood is for living tissues.
In muscle, resistance exercise increases the breakdown of proteins but it also turns the rate of synthesis way up in response. The net result once all that settles down is a muscle with more proteins packed in it ― a bigger muscle.
Like muscles, tendons are responsive to mechanical stress. Any kind of stretch or contraction triggers a cascade of biochemical signals which in turn triggers protein synthesis. Muscles build more of the contractile proteins actin and myosin. Connective tissues build more collagen.
A tendon which is being loaded regularly is receiving a regular supply of blood, and that in turn keeps collagen synthesis humming along. Collagen synthesis means that the tendon can heal from damage and, like muscle, can reinforce itself.
The opposite holds true: a tendon which isn’t receiving blood is a tendon which isn’t synthesizing collagen. While loading a tendon increases collagen repair, likely by way of increased blood supply, inactivity does the exact opposite. In animal studies, an immobilized tendon gradually becomes weaker and more prone to injury.
In humans, endurance training stimulates specific changes in tendon strength which are probably due to increases in blood flow, and the loading of strength training does even more. There’s a reason that old-timers said that lifting maximum weights would build “attachment strength”. These were the same old-timers who lifted regularly, rather than squatting once and letting everything waste away for the next week.
Loading a specific tendon ― say the quadriceps tendon ― only once a week means that the muscle will heal up just fine. Blood will pump in and out, and even though you’ll be sore and stiff for a few days, the tissue will restore itself.
The poor tendon, all it got was a brief spike of blood while it was massively loaded, and then the next week was spent rotting away with no way to repair itself. Lack of oxygen eventually leads to degenerative changes within the tendons, with a weaker form of collagen replacing the damaged segments. Over time, not keeping your tendons mobile and loaded after strenuous exercise can actually make them weaker.
This means that Broz was largely right. Training hard but only infrequently, with the goal of “getting more rest”, actually aggravates joint and connective tissue injuries, doing the exact opposite of what’s needed to keep them healthy.
Age is no excuse, either. If you’re older, you’ve got all the more reason to stay active.
Tendons stiffen with age as metabolic by-products accumulate in the collagen structure.
The stiffening leaves the tendon stronger, but this is a double-edged sword. Collagen turnover is inhibited in the age-altered tendon, leaving them more robust but less adaptable.
Never well-fed even on a good day, the connective tissues virtually starve as you move into old age. You get stiffer, more prone to injury, and in response you do less of the very thing that could improve the situation. We need to keep our joints mobile as we get older, even if that’s just body-weight exercise, high-rep work with bands, or plain-old bodybuilding.
As I found, heavy squatting (and pressing and pulling) seem to get the job done too (provided you ease into them).
Given all this, it’s no wonder that infrequent maximal training leads to so many injuries. You load up the tendon and then leave it to rot for a week, 10 days, even longer.
Linear thinking says that training more often would only aggravate your tissues and add to your risk, but this isn’t the case. Tendons and ligaments need movement, and they need blood flushed through them regularly. They need to be exposed to regular activity.
Otherwise you wind up with very strong muscles that can demonstrate amazing strength – and tendons that blow at the first opportunity. As Kjaer says in his papers, tendons need altered loading, not rest. It does you no good to be strong as an ox when you have tendons made of tissue paper.