The Role of Protein Following Intense Exercise in Competitive Youth Athletes

Abstract

The overall purpose of this thesis was to examine the role of post-exercise dairy protein consumption (isolated and whole-food) on recovery indices (performance and muscle damage) and inflammation following intense exercise within the context of different ecologically valid sporting environments, i.e., acute competition and a short-term period of intensified training, in competitive youth athletes. For this, two studies were conducted. Study 1 (Chapter 3) investigated the effect of whey protein consumption following a high-intensity interval swim session (HIIS) among adolescent swimmers on subsequent performance, muscle soreness, plasma creatine kinase and inflammatory cytokines, compared with isoenergetic carbohydrate and flavoured water in the acute (0–8 h) and short-term (8–24 h) recovery periods. Study 2 (Chapter 4) examined the effects of increased protein consumption, via plain Greek yogurt, compared with an isoenergetic carbohydrate control on performance recovery, inflammation, and muscle damage, during a 5-day simulated soccer training camp in competitive adolescent female soccer players. The collective findings indicate that during both acute and short-term periods of intensified exercise, the provision of dairy protein regardless of form (isolated or whole food), provided no added benefit at enhancing performance recovery or ameliorating muscle damage above that of energy matched carbohydrates. However, it does appear that the consumption of calories, regardless of type (e.g., carbohydrates or dairy protein), when rapid recovery is required, offers greater performance retainment than water. Therefore, during periods of intensified exercise that may be accompanied by inadequate recovery, the replenishment of energy should be the primary focus. Further, in both studies the consumption of dairy protein following exercise leads to an augmented anti-inflammatory response (i.e., increased IL10), not observed in the control conditions (i.e., water or energy-matched carbohydrates). Thus, it is possible that dairy protein consumption post-exercise may benefit the acute immune response. This possibility requires further study.