Nutrition for injuries

When an athlete sustains an injury, attention focuses on treatment and rehabilitation, while nutrition is often reduced to a single rule: "I move less — I eat less". Yet it is exactly during this period that the diet can either speed the return to training or aggravate muscle loss and slow healing. The editorial team examined what current reviews say about the nutritional support of an injured athlete.

What happens in the body after an injury

The healing of any injury goes through several phases. First inflammation develops: immune cells arrive at the damaged area and clear the tissue of destroyed structures. Then comes the proliferation phase, when new tissue forms, and finally the remodelling phase, during which it gradually strengthens and acquires function.

Inflammation is often perceived as something harmful, but at the early stage it is necessary. Attempts to fully "extinguish" it with large doses of anti-inflammatory agents or antioxidants can theoretically interfere with normal healing. So the task of nutrition is not to fight inflammation, but to provide the tissues with material and energy for recovery.

In parallel, another process takes place — the loss of muscle mass through inactivity. The review by Wall, Morton and van Loon (2015) describes that already within the first days of immobilising a limb, muscles noticeably shrink. The main cause is not so much accelerated breakdown as a reduction in muscle protein synthesis and a worsening of the muscle response to dietary protein.

Thus an injured athlete faces two tasks at once: to heal the damaged tissue and to preserve as much muscle as possible in the undamaged areas. Nutritional decisions must take both processes into account.

Energy: why you should not cut calories sharply

The intuitive reaction to an injury is to cut calories sharply so as not to gain fat. Yet Tipton (2015) points out that energy expenditure during an injury decreases less than it seems. Healing itself requires energy, and severe injuries and operations raise basal metabolism.

In addition, moving on crutches is energetically expensive: walking with them requires several times more energy than ordinary walking at the same speed. An athlete who moves around a lot on crutches may expend more than they expect.

An energy deficit during rehabilitation has clear negative consequences: it accelerates muscle loss and can slow healing. It is therefore recommended to aim for maintenance calorie intake, reducing it only moderately in line with the real decrease in activity, rather than switching to "cutting".

In practice this means: reduce the share of carbohydrates linked to training load, but keep a sufficient amount of protein, vegetables, fruit and healthy fats. Regular weighing will help notice in time both excessive gain and undesirable loss of weight.

Protein and preserving muscle

During immobilisation, muscles become less sensitive to protein — this phenomenon is called anabolic resistance. To compensate for it, reviews recommend keeping protein intake at a level no lower than during training. Tipton (2015) and Smith-Ryan and colleagues (2020) give guidelines of around 1.6–2.5 g per kilogram of body weight per day.

Distribution also matters: 4–5 intakes of 20–40 g of protein with a sufficient leucine content throughout the day provide repeated stimulation of muscle protein synthesis. A portion of protein before sleep can be one more intake, especially for older athletes.

Creatine is one of the most studied supplements in the context of immobilisation. In the study by Hespel and colleagues (2001), creatine during rehabilitation after immobilisation of the leg accelerated the recovery of muscle area and strength. The results of other work are inconsistent, but given the safety of creatine for healthy people, some specialists consider it a reasonable choice.

As for omega-3 fatty acids, some studies suggest that they may partly reduce the loss of muscle mass during inactivity. The evidence base is still limited, so they are regarded as a supplement to the diet rather than the main tool.

Collagen, vitamin C and other nutrients

Tendons and ligaments consist mainly of collagen, so the idea of supporting them with the corresponding amino acids looks logical. The study by Shaw and colleagues (2017) showed that taking gelatin together with vitamin C roughly an hour before a short jumping exercise raised markers of collagen synthesis in the blood.

The key point of this strategy is combining it with loading. Collagen is not "delivered" into a ligament on its own; collagen synthesis in the tissue is stimulated by mechanical stimuli, and the amino acids from the supplement only provide the raw material. So the intake is usually tied to rehabilitation exercises.

• Vitamin C— a cofactor of enzymes needed to form the stable structure of collagen.
• Zinc— participates in wound healing and the work of the immune system; important with a deficiency.
• Iron— a deficiency worsens the supply of oxygen to tissues and well-being during rehabilitation.
• Vitamin D— affects bones, muscles and immunity; it is advisable to check the blood level.

As for trace elements in general, reviews emphasise: their additional benefit is evident primarily in the presence of a deficiency. Megadoses of vitamins and minerals do not speed healing in a person with normal status, and some, for example an excess of zinc, can impair the absorption of other elements.

The foundation remains a varied diet with a sufficient amount of vegetables, fruit, berries, fish, eggs, dairy products and whole grains. Such a diet covers most trace element needs without special supplements.

Bone injuries and typical mistakes

For fractures and stress fractures, calcium, vitamin D and overall energy availability are of particular importance. Close and colleagues (2019) in guidelines for track and field athletes emphasise that chronic energy deficiency is one of the important causes of stress fractures, especially in sports where low body weight is valued.

Relative energy deficiency in sport (RED-S) disrupts hormonal regulation, lowers bone density and slows bone healing. So an athlete with a stress fracture must not only heal the current injury but also assess whether they are getting enough energy over the season.

Among the typical mistakes of injured athletes, the editorial team highlights the following: sharply cutting calories, lowering protein "because I'm not training", excessive enthusiasm for large doses of anti-inflammatory drugs and antioxidants, and alcohol, which worsens muscle protein synthesis and healing.

Another mistake is to expect miracles from supplements. No supplement can replace properly structured rehabilitation under the supervision of a doctor and a physical therapist. Nutrition creates favourable conditions, but the main stimulus for recovery remains graded exercise.

Editorial conclusions

During an injury the body needs energy and building material, so sharply cutting calories and protein harms both healing and the preservation of muscle.

The most well-founded steps are maintenance calorie intake, 1.6–2.5 g of protein per kilogram of body weight with an even distribution, and a varied diet. Creatine, omega-3 and collagen with vitamin C can be an addition, but their evidence base is more modest.

For bone injuries it is worth separately assessing vitamin D, calcium and overall energy availability to prevent repeat damage.

The editorial team also recommends familiarising yourself with our materials about nutrition for joint health, about collagen for ligaments and about protein at night.

References

1. Tipton KD. Nutritional support for exercise-induced injuries. Sports Med. 2015;45 Suppl 1:S93–S104.
2. Wall BT, Morton JP, van Loon LJC. Strategies to maintain skeletal muscle mass in the injured athlete: nutritional considerations and exercise mimetics. Eur J Sport Sci. 2015;15(1):53–62.
3. Smith-Ryan AE, Hirsch KR, Saylor HE, Gould LM, Blue MNM. Nutritional considerations and strategies to facilitate injury recovery and rehabilitation. J Athl Train. 2020;55(9):918–930.
4. Shaw G, Lee-Barthel A, Ross ML, Wang B, Baar K. Vitamin C-enriched gelatin supplementation before intermittent activity augments collagen synthesis. Am J Clin Nutr. 2017;105(1):136–143.
5. Hespel P, Op't Eijnde B, Van Leemputte M, et al. Oral creatine supplementation facilitates the rehabilitation of disuse atrophy and alters the expression of muscle myogenic factors in humans. J Physiol. 2001;536(Pt 2):625–633.
6. Close GL, Sale C, Baar K, Bermon S. Nutrition for the prevention and treatment of injuries in track and field athletes. Int J Sport Nutr Exerc Metab. 2019;29(2):189–197.