Nutrition during injury: what not to cut

A fighter breaks a hand. He stops training, so he stops eating properly, because eating like an athlete while sitting on a sofa feels absurd. Six weeks later the cast comes off and he has lost more muscle than the injury alone would have taken.

That sequence is almost universal and it is almost entirely avoidable. The instinct is understandable and it is wrong in a specific, measurable way.

What actually happens to the muscle

Two things go wrong, and only one of them is the one people expect.

Basal muscle protein synthesis falls. That much is obvious. The second is less intuitive and matters more: the muscle becomes resistant to anabolic stimulation. Protein that would normally trigger a robust synthetic response triggers a blunted one.

Disuse impairs the muscle's response to protein ingestion, and that resistance is the most prominent metabolic contributor to the loss.

The scale of it is quick. One week of immobilisation in healthy young men, in energy balance, produced a reduction of around 3 percent in quadriceps cross-sectional area and roughly 1.4 kg of lean tissue lost.

Note that phrase: in energy balance. That is the result when nutrition is done correctly. Everything below is about not making it worse.

The energy mistake

The natural response to not training is to eat less, and there is a reasonable-sounding argument behind it: less activity, fewer calories, no fat gain during the layoff.

The problem is the timing. Five days of energy deficit is enough to significantly diminish muscle protein synthesis, on top of a muscle that has already stopped responding properly.

You have applied a second brake to a system that is already slowing.

And the saving is smaller than it looks. Energy requirements during injury are reduced less than most people assume: wound healing carries a metabolic cost, crutches and compensatory movement are inefficient, and the body is running a repair process.

Protein, which goes up rather than down

This is the number to write on the fridge, because it runs against every instinct in the situation.

Higher protein intakes in the region of 2 to 2.5 grams per kilogram of body weight per day appear warranted during immobilisation. Higher than a normal training day, at the moment you are doing nothing.

The logic follows from anabolic resistance. If the muscle responds less to a given dose, a larger dose is needed to produce the same signal.

The supporting evidence is an extrapolation and I will label it as one. In healthy athletes after whole-body resistance exercise, 40 grams of whey produced a greater synthetic response than 20 grams, which is not what the older literature on dose ceilings predicted. That study was not done on immobilised muscle. The reasoning that carries it across is physiological rather than demonstrated: inactive tissue with a blunted response needs a larger single dose to clear the leucine threshold and trigger synthesis at all.

The absolute minimum, stated in the reviews and worth repeating because it is where most fighters fail: if energy intake falls, do not let the absolute amount of protein fall with it. A fighter eating less overall and keeping protein at the same grams per day is doing the most important part correctly.

Practically: 35 to 45 grams per meal, 4 to 5 times a day, from whole protein sources. Not sipped through the day, not concentrated into one evening meal.

The finding that belongs to boxers

Creatine is the supplement most often suggested during injury, and the evidence has a split in it that nobody mentions and that happens to matter enormously in this sport.

It is also, unlike glucosamine and chondroitin, a compound tested in people who train.

Boxing breaks hands. Metacarpals, scaphoids, wrists, the occasional forearm. The single situation where creatine has shown a protective effect during immobilisation is the upper limb, which is the limb this sport immobilises most.

Two caveats before anybody empties a tub. The evidence base is small and the reviewers describe the case as unresolved. And creatine causes water retention, which is irrelevant during a layoff and becomes relevant again before a weigh-in, so the stop date rules from the camp protocol still apply.

That timing is in the creatine article.

Where the evidence is more consistent is the rehabilitation phase rather than the immobilisation phase. Creatine during the 10 weeks of getting the limb back appears to help more than creatine during the 6 weeks in a cast.

Do not switch off the inflammation

The instinct after an injury is to attack the inflammation with everything available: high-dose antioxidants, anti-inflammatory supplements, whatever is in the cupboard.

Inflammation is part of wound healing. Reviewers make the point plainly: given the importance of the inflammatory process for healing, attempting to drastically reduce it may not be ideal for recovery.

High-dose antioxidant work in rodents has shown effects on muscle loss, and the reviewers note that the equivalent doses in a human would likely be problematic and potentially toxic.

That is not a research finding to act on.

The same logic applies to the polyphenol supplements sold for recovery, for the reasons set out in the tart cherry article. Blunting inflammation is useful between competitions and questionable while tissue is repairing.

Omega-3, honestly

There is preliminary evidence that omega-3 supplementation may reduce muscle loss during disuse, and longer-term intake appears to enhance anabolic sensitivity to amino acids, which is precisely the problem an immobilised limb has.

That is a promising mechanism and it is not a proven intervention. The reviews are explicit that the appropriate dose in injured people has not been established, and that the data should be considered preliminary.

My position: if you already take omega-3, this is a reason to keep taking it rather than a reason to increase it. Dose and form are covered in the omega-3 article.

The part that is not about food

Two things go wrong in a layoff that have nothing to do with macronutrients and cost more than any of them.

Alcohol. The layoff is when a fighter is not in camp, not making weight, bored and frustrated. Alcohol impairs protein synthesis and disrupts sleep, at the exact point when both are the mechanism of recovery.

There is no version of this that helps.

Anti-doping does not pause because you are injured. If you are in a testing pool, whereabouts obligations continue while your arm is in a cast, and the administrative failures that carry sanctions do not care that you cannot train.

Meanwhile you are suddenly being prescribed painkillers and possibly more by a doctor who does not work in sport.

What the reviews agree on

A systematic review of nutritional strategies in the rehabilitation of musculoskeletal injuries in athletes reached a short and unglamorous list: balanced energy intake, high protein, adequate carbohydrate, and supervision to avoid low energy availability.

Collagen, creatine, omega-3 and vitamin D were described as promising and requiring further research. The reviewers also noted how little clinical research exists in injured athletes specifically, relative to the number of review articles written about it.

Read that as it is meant. The foundation is energy and protein, done consistently for weeks.

The supplements are a margin around it, and anybody selling you the margin as the intervention has the proportions backwards.

The weeks that decide the next camp

Fighters treat a layoff as time removed from their career. It is not. It is a phase with a job, and the job is arriving at the start of the next camp with your muscle intact and your body composition close to where it was.

Get that wrong and the next camp starts further from the weight, with less muscle to protect, which makes the cut harder and the camp worse. That is how one broken hand turns into two bad fights.

What to do in the return phase specifically is in coming back after a layoff.

Eat like an athlete who is injured, not like a person who has stopped being an athlete. The difference between those two is roughly the difference between the fighter who comes back and the one who comes back diminished.