Many of you may read the title and contest that there is no difference between muscle repair and muscle recovery, and to an extent they are one and the same thing. You can’t have recovery without first repairing muscle… The reason I differentiate the two is because ‘repairing’ a muscle per se prompts various mechanical and structural adjustments to the muscle. On the other hand, ‘recovery’ refers to the replenishment of key metabolites and energy sources needed for optimal muscle function. Yes ‘recovery’ encompasses repair as a whole, but when it comes to supplementing for optimal muscle recovery there are certain forms of protein that suit repair and recovery in their own right.
Fast release protein
The term ‘fast release’ refers to the rate in which a protein source (liquid protein in this case) enters the blood stream through the stomach and bowel. Quite predictably then, a ‘fast release’ protein does this relatively quickly compared to a ‘slow release’ protein which enters the blood supply more slowly. Solid food would require a considerable amount of chemical and mechanical digestion meaning it could take several minutes or hours for the amino acids to reach the blood and tissue. Conversely, a liquid protein source such as milk or whey protein (for example) is semi- elemental, meaning they are already partially digested upon entering the stomach. The result is a much faster uptake of amino acids into the muscle and organs for REPAIR! Physical activity such as exercise stresses the muscle, resistance training (lifting weights) places particular stress on the muscle fibres often resulting in micro tears in the muscle. These small tears are needed to invoke repair and supercompensation (growth beyond that of normal). With this in mind then, a slower releasing protein may well be beneficial as well in order to stop them from developing into bigger tears and pulls come the next training session….
Slow release protein
Although a solid food source is generally a ‘slower releasing’ protein because of the extra digestion it requires, a liquid form of protein can actually be a ‘slow release’ protein too. So even though the protein source is liquid, and much of the digestion is already done, the chemical structure of a casein protein is such that it requires more digestion and thus slows the protein release. If a fast releasing protein (such as whey protein) is consumed immediately after a training session, then the amino acid influx is channeled to the muscle for a quick muscle repair and structural repletion.
United as one…
Do I believe that fast (whey) and slow release proteins (casein) are uniquely distinct…no, both proteins are key to the overall picture of muscle RECOVERY and GROWTH. What makes the two unique is whey proteins inherent ability to get to the muscle quickly in order to patch up the damage done by training. The patch work doesn’t then stop there, the muscle is metabolically active days after the training stimulus meaning it needs to be fed then too. Should you train of an evening, consume whey protein or indeed any other quick releasing forms of protein (rice, hemp, pea, soya) immediately after then great. However, should you then proceed to eat a meal early evening only to leave it another 2-3 hours before bed, then guess what, your muscles are going 7-8 hours overnight with elevated protein requirements and just the meal you ate to keep it going…this will only feed the muscle for a few hours.
Real RECOVERY occurs after the initial repair process, muscle repair will only do so much in your pursuit of lean mass, size and/ or optimal muscular function. The repletion of muscle protein via slower releasing proteins (casein) will help to prepare the muscle for the next bout of exercise. So in all its simplicity, whey and casein protein work as one, they both deliver biologically available (readily absorbed) amino acids for the muscle to use both instantly (whey) and during the time when you can’t practically ingest protein e.g. sleep. So for best results consume a whey protein within 30mins after physical exertion for optimal repair, followed by casein protein approx 60mins before bed for optimal recovery.