Nutrition plays an integral role in optimising the performance of any elite athlete. In the case of football players, nutrition is of utmost importance during training and matches and, certainly, during injury recovery.

It is worth emphasising that the nutritional aspect of elite football players is based on the premise of food first rather than supplements. In fact, in a market with an oversaturated supply of nutritional supplements, it is now more necessary than ever to provide relevant scientific evidence on any nutritional aspect, within the constraints of what is effective, practical and feasible in the football environment. The science underpinning sports nutrition is evolving rapidly and practitioners need to keep an eye out for new findings.

In recognition of these developments, the Union of European Football Associations (UEFA) issued a consensus statement, the “UEFA expert group statement on nutrition in elite football. Current evidence to inform practical recommendations and guide future research (James Collins et al., 2020),” for which it brought together experts in applied sports nutrition research, as well as professionals working with elite football clubs and national associations/federations, on a number of relevant topics around elite football nutrition. The role of nutrition in injury recovery is one of these topics.

Nutritional needs in the rehabilitation process

The high physical demands of elite sport coupled with increasingly dynamic movements result in a high risk of injury. And when an injury occurs, teams face a unique challenge: to recover the player as quickly and safely as possible. In this circumstance, nutrition can help to optimise the rehabilitation process and aid the targeted return.

Most injuries quickly trigger inflammatory processes that cause wound healing and soft tissue and/or bone repair – the injury healing process. At this point, sufficient energy and protein intake must be ensured and deficiencies of calcium, vitamins D and C, zinc, copper and manganese, which can disrupt the initiated healing process, must be avoided.^{1, 2}

Furthermore, as football injuries generally occur when intense muscle contractions occur, this is likely to exacerbate the level of systemic and local inflammation after the injury – a physiological response that is assumed to contribute to subsequent muscle and/or tendon unconditioning.³

While a variety of so-called ‘nutraceuticals’ (products presented as a pharmaceutical alternative claiming physiological benefits) – including phenolic compounds, curcuminoids and n3-polyunsaturated fatty acids – have been proposed as potential ways to combat the acute inflammatory process,⁴ it is necessary to keep doing studies on their anti-inflammatory effects in humans.

Nutrition to sustain fitness during injury

After the initial scarring and healing response, comes the rehabilitation phase, which is possibly of greatest nutritional relevance to the injured football player due to the time spent in this phase; rehabilitation requires a period (days to months) of whole body (e.g., hospitalisation/bed rest) or body part disuse (e.g., limb immobilisation), and/or reduced activity (e.g., reduced/absent training load). During this time, rapid deterioration of soft tissue and bone can be expected as a result of mechanical unloading:

• Skeletal muscle appears to be the tissue most susceptible to disuse, with atrophy and deconditioning (e.g., reduced force-generating capacity) evident after only a few days.⁷

• Bone demineralisation occurs in bone as early as one week after disuse.⁸

• Although the tendon tissue appears more resistant to disuse atrophy, within about two weeks their metabolic activity and functionality are affected.^{9, 10}

This indicates that changes in energy requirements should be monitored during rehabilitation and it is necessary to adjust energy and meal distribution to modulate the effects of deconditioning..^{11, 12}

The importance of protein

A reduced dietary protein intake will accelerate the loss of muscle mass regardless of energy balance.¹³  Resistance to anabolism due to inflammation and lack of use requires specific stimuli in the form of protein boluses with sufficient leucine.^{14, 15}

In this regard, current recommendations to alleviate muscle loss (and regain muscle) during rehabilitation include distributing^{16, 17} adequate amounts (20-30 g)^{18, 19}of leucine-rich protein (≥2.5 g per meal)¹⁵ throughout the day, even before bedtime.¹⁴ It should be noted that the efficacy of such an approach is supported by (limited) laboratory data²⁰ and applied case studies in elite athletes,²¹ with the resulting recommended daily protein intake of ≥1.6 g/kg body mass.²²           

Collagen protein deserves separate consideration as it is very important at this stage of injury since the rate of bone collagen protein synthesis also increases in response to the provision of protein,²⁷ with an overall positive effect on bone turnover.²⁸ Collagen present in muscle also appears resistant to the anabolic effects of protein.²⁷

All in all, the data available suggests that the nutritional considerations for bone and tendon rehabilitation are similar to muscle rehabilitation after injury in terms of energy balance and macronutrient intake.

It should be noted that different stages of injury call for different nutritional needs based on the stage and duration of the injury. As an example, a recent case study calculated energy expenditure of ~3100 kcal/day during the first 6 weeks of anterior cruciate ligament (ACL) rehabilitation in an elite Premier League player,³¹ which is close to the energy expenditure of players in full training.

Given the metabolic demands of the tissues/wound recovery process, the most significant nutritional issue during rehabilitation is perhaps to remain as close as possible to energy balance, and therefore to avoid drastic reductions in nutrients intake.

References:

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