Can post-injury nutrition affect your healing and recovery outcomes for the better?
When injury strikes, maximizing the speed of recovery is crucial for athletes seeking a speedy return to sport. Most athletes will already be familiar with methods such as rest, ice (to combat inflammation), stretching etc in an attempt to enhance recovery following an injury. But are there any other tools that can help you?
In particular, is there a role for nutritional intervention? Although clinical studies are very thin on the ground, some recent research suggests that post-injury nutrition can and does play a role in healing and recovery, which is what we will explore here.
Exercise-induced injuries generally have two main phases, both of which may be influenced by nutrition:
1. Inflammation/immobilization/atrophy stage (first stage)
In the initial stages, an inflammatory response is initiated, which is generally considered to be necessary for proper healing. This inflammatory stage may last for several hours up to several days depending on the injury. Depending on the type and severity of the injury, immobilization can last from a few days to several months.
During this time, metabolic changes in the tissues resulting from inactivity lead to loss of strength and function (see figure).One these changes involves loss of muscle mass. However functional problems can also result as a result of damage to other tissues, such as tendons and ligaments.
2. Rehabilitation and increased activity of the injured limb (second stage)
This phase follows the return of mobility leading to muscle mass growth (hypertrophy) and the return of functionality to the injured area. Unfortunately, the complete recovery of strength and function following injury-induced immobilization takes much longer than the time it takes to lose them. In this phase, regenerating muscle tissue and consolidating the healing process (eg fracture healing, tendon repairs etc) are important.
Whereas optimum nutrition is similar for these two stages, there are some key differences. For example, in phase one, nutrients that can reduce excessive (and counterproductive) inflammation could – in theory at least – be useful. In phase two for example, nutrients that might augment the process of knitting tendon to bone following tendon repairs could be particularly helpful.
While inflammation is part of the healing process, it seems sensible that avoiding excessive inflammation is a worthwhile strategy at this stage. In recent years, evidence has accumulated that omega-3 polyunsaturated fats (PUFAs) such as EPA and DHA have potent anti-inflammatory actions. Synergistically, EPA and DHA play a role in controlling and limiting the inflammation process. This is achieved through biologically active compounds known as ‘inflammatory mediators’ such as prostaglandins, leukotrienes, lipoxins, resolvins and protectins. However, the problem however is that research on the necessary dose of omega-3 oils to elicit an antiinflammatory effect in humans is still limited. Nevertheless, taking the evidence in the round, it is reasonable to assume that in the acute phase following an injury, one should try to increase their omega-3 intake and omega-6 intake. As well as EPA/DHA supplements, this means eating more fatty fish (salmon, trout, sardines, herrings etc) flax seed oil, walnuts, pumpkin seeds etc, while reducing intakes of omega-6 fats – commonly found in vegetable oils, such as corn and sunflower, and processed foods containing them (check labels!).
*Protein (to prevent muscle loss)
During immobility following injury, the most obvious change is a loss of muscle mass leading to reduced muscle function. Inactivity results in rapid muscle loss, and the primary metabolic factor leading to muscle loss is decreased muscle protein synthesis. Therefore, increased protein intake is often the first nutritional countermeasure. However, while protein or essential amino acid intake increases muscle protein synthesis (both at rest and following exercise), this anabolic (muscle building) effect is blunted during prolonged periods of immobilization. One possible way round this effect is to consume protein such as whey, which is rich in the amino acid leucine.
*Calories and energy
Another important consideration during injury-induced immobilization is the total energy intake (ie calories consumed). Depending on the extent of mobilization, a substantial decrease in total energy expenditure is likely because exercise is either more difficult or virtually impossible. This explains the necessity for an injured athlete to significantly reduce energy intake to avoid excessive weight gain.
However, athletes should be cautious not to take this strategy too far. That’s because, during the injury healing process, energy expenditure is increased significantly, particularly early on and if the injury is severe . So, the reduction in calorie intake may not need to be too drastic. In injuries where crutches are required for walking, there’s also an additional energy requirement to be considered. A third caveat is that any insufficiency in energy intake will impair optimal muscle protein synthesis, in turn leading to greater muscle tissue loss. A balance therefore needs to be struck, and overall, a small amount of weight gain (which can be shed when you resume training) may actually be preferable to a lack of calorie intake, which is needed to support proper muscle healing and minimize inactivity-related muscle protein loss.
As mentioned above, leucine-rich protein consumed as whey has been shown to be a superior source of protein. However, with increasing activity, your total energy intake will need to rise accordingly. In particular, adequate carbohydrate intake should be ensured to help fuel your increasing activity level, particularly as muscle protein synthesis is an energetically expensive process, which will further increase energy requirements.
Studies on muscle damage and recovery also suggest that immediate post-exercise feeding of protein combined with carbohydrate can further enhance muscle tissue synthesis.
Reference : Peak Performance Journal