This week I chaired a session at the ECOSEP conference in Barcelona. Some of the top researchers in the field of muscle and tendon injury research got together in the amazing facilities of the great Barcelona Football Club. I was asked to bring together 3 experts in the field of nutrition and chair a session with the title: Nutrition for recovery from injury. Professors Kevin Tipton from the University of Stirling, in Scotland, Stuart Phillips from McMaster University in Canada and Keith Baar from the University of California at Davis all presented their work and recommendations. Below is my summary of the event.
Muscle building and protein intake
Muscle and tendon injuries are very common. In elite sport these injuries may account for ~70% of all visits to a sport physician or athletic trainer/physical therapist. Kevin Tipton kicked off the session with setting the scene and focusing on the muscle where we have far more data than the tendon. In order to improve muscle building, protein intake is important. Building muscle is the result of a dynamic process whereby constantly proteins are made out of amino acids (synthesis) and also broken down. The net effect of synthesis and breakdown will determine muscle gain (or loss). Protein feeding can result in improved synthesis. Breakdown seems to be slightly less important in this process. A meal containing 20-25 grams of high quality protein results in optimal rates of protein synthesis. Ingesting more results in oxidation of the protein and urea formation and is not beneficial.
A meal containing 20-25 grams of high quality protein results in optimal rates of protein synthesis.
Energy balance is important
Kevin also stressed that energy balance is an important factor during the recovery from injury. Both negative energy balance (eating too little) and positive energy balance (eating too much) can have detrimental effects on protein synthesis.
Because protein synthesis and breakdown are processes that cost a lot of energy, it is important to take this into account. Inflammation could further increase energy needs. On the other hand activity patterns change and an athlete especially when limbs are immobilized will have reduced energy expenditure as a results of this. Thus energy expenditure will change significantly when an athlete is injured and therefore intake needs to be managed carefully.
Prof Phillips then discussed the concept of “anabolic sensitivity”. Essential during period of inactivity the muscle becomes less sensitive to anabolic (muscle building) stimuli and thus it becomes more difficult to make muscle. One important signal is leucine. This amino acid acts as a trigger for protein synthesis but when inactive (immobilized muscle), more leucine is needed for the same stimulation of protein synthesis. Initially protein feeding may help with increasing synthesis but after a while exercising the muscle will become essential for increased muscle protein synthesis. From a practical point of view it is therefore essential to exercise the muscle as early as possible in the rehab process (pool-work and electrical stimulation of the muscle).
From a practical point of view it is therefore essential to exercise the muscle as early as possible in the rehab process
Protein feeding should be high quality (whey) protein containing a high amount of leucine. It is recommended to take 20g of high quality protein (0.3 g/kg/meal) at EVERY meal. As discussed above this amount should maximally stimulate protein synthesis. Protein timing should be around the rehab sessions and meals should be regular and 4 times per day. Other nutrition that could possibly help, with some evidence include creatine (10g/d for 3 weeks then 2 g/d beyond), and, with less evidence, HMB and omega-3-fatty acids.