Exercise and sports performance recovery.
Dr. Brendan Egan discusses exercise recovery and the function yogurt can provide as a nutrient-rich food.
The challenge of exercise and training: implications for recovery
Exercise training, especially when intense, presents a major challenge to the body. As a result, many recovery processes begin soon afterwards including recovery of fuel stores, repair of damaged muscle, restoration of fluid and electrolyte balance, and inflammatory and anti-inflammatory responses. Optimising recovery is paramount to sports nutrition strategies because these processes directly influence the ability to perform future exercise sessions, and the extent of adaptation to exercise especially in relation to increasing muscle size.
The recovery of muscle fuel stores, also known as glycogen resynthesis, has traditionally received a lot of focus from sports nutritionists, but focus is increasingly turning to the repair, growth and remodelling of muscle as part of a holistic approach to recovery. Over the last 15 years, several key nutrition strategies for recovery have been established primarily focussing on the influential effects of (a) the timing of feedings, and (b) the composition of nutrients. Much of this work now focuses on the optimal blend of carbohydrate and protein, and in particular the role for dairy protein in these strategies.
The importance of recovery nutrition: timing and composition
The “nutrient timing” concept suggests that instead of focussing only on which nutrients are eaten, when those nutrients are eaten around exercise dramatically affects recovery from that session, and influences how much fat is lost or muscle is gained over time. This is explained by a phenomenon known as the ‘post-exercise window of opportunity’, a short period of time (up to 4 hours) after exercise where recovery processes are maximised. Feeding a nutrient-rich meal in this time period is paramount for recovery.
The composition that would be optimal for recovery is one that combines both a source of carbohydrate and a source of protein, as these nutrients work in concert to support recovery. Consensus from the International Society of Sports Nutrition suggests ratios of carbohydrate-to-protein of 3:1 to 5:1 are optimal for recovery. Specifically, a combination of sources of high glycemic index carbohydrate and protein rich in essential amino acids is suggested to be the ‘perfect’ recovery mix.
Yogurt and dairy as foods for recovery from exercise
As it happens, dairy foods fit this nutrition profile extremely well, and recent research has revealed dairy foods as recovery aids, for which they are now well-regarded. Since milk contains both carbohydrate, protein, fluid and electrolytes, it has been proposed as a low-cost alternative to off-the-shelf powdered recovery supplements. On the whole, the evidence for milk as a post-exercise recovery aid is promising with beneficial effects reported for hydration and markers of muscle damage.
Regarding the source of protein during recovery, a clear advantage exists for including the building blocks of proteins known as essential amino acids and, in particular, one named leucine. Dairy protein is one of the richest food sources of leucine. Dairy protein stimulates markers of growth of muscle to a greater extent than most other proteins. Because of this nutrient profile, ease of flavouring and versatility for combining with other foods such as fruit, there are many simple food combinations that combine yogurt and dairy foods that can be hugely beneficial to recovery from exercise.