Effects of Post-Exercise Whey Protein Consumption on Recovery Indices in Adolescent Swimmers

Abstract

Purpose: This study examined the effect of whey protein consumption following high-intensity interval swimming (HIIS) on muscle damage, inflammatory cytokines and performance in adolescent swimmers. Methods: Fifty-four swimmers (11–17 years-old) were stratified by age, sex and body mass to a whey protein (PRO), isoenergetic carbohydrate (CHO) or a water/placebo (H2O) group. Following baseline blood samples (06:00 h) and a standardised breakfast, participants performed a maximal 200 m swim, followed by HIIS. A total of two post-exercise boluses were consumed following HIIS and ~5 h post-baseline. Blood and 200 m performance measurements were repeated at 5 h, 8 h and 24 h from baseline. Muscle soreness was assessed at 24 h. Creatine kinase (CK), interleukin-6 (IL-6), interleukin-10 (IL-10) and tumor necrosis factor-alpha (TNF-α) were measured in plasma. Results: No difference in 200 m swim performance was observed between groups. CK activity was elevated at 5 h compared to baseline and 24 h and at 8 h compared to all other timepoints, with no differences between groups. Muscle soreness was lower in PRO compared to H2O (p = 0.04). Anti-inflammatory IL-10 increased at 8 h in PRO, while it decreased in CHO and H2O. Conclusions: Post-exercise consumption of whey protein appears to have no additional benefit on recovery indices following HIIS compared to isoenergetic amounts of carbohydrate in adolescent swimmers. However, it may assist with the acute-inflammatory response.

Changes in Inflammatory Cytokines and Irisin in Response to High Intensity Swimming in Adolescent versus Adult Male Swimmers

“…The first visit was an information session, which also included anthropometric measurements. Details of the measurements can be found in McKinlay et al [26]. In brief, body fat and body mass (kg) were collected using bioelectric impedance analysis (InBody520; BioSpace Co, Ltd., Madison, MI, USA).…”

“…Immediately after the resting blood sample and~1 h before swimming, participants were provided a standardized breakfast of~300-500 kcal (depending on body mass), which included a granola bar, muffin, fruit (banana or apple) and a juice box or water. Details of the ingredients of the breakfast can be found in McKinlay et al [26].…”

“…Participants in the current study included 16 adolescent (11-15 years old) and 16 adult (18-30 years old) male swimmers, who trained and competed for at least four years, were free of injuries and any medical condition that prevented them from participating and were not taking medications or nutritional supplements. Swimmers were recruited from two varsity teams and five local swim clubs in Southern Ontario as part of a larger study designed to examine the effect of post-exercise whey protein consumption on subsequent exercise performance, muscle damage, and inflammation [26]. Data presented in this study are a secondary analyses of blood samples taken before the protein/carbohydrate supplementation protocol and solely focus on acute responses to intense swimming.…”

“…The swimming trial commenced~1.5 h after the pre-exercise blood draw (~1 h postprandial) and it was designed for the purposes of the larger study to mirror a day of swimming competition. Details of the larger study's protocol and measurements can be found in McKinlay et al [26]. Briefly, the trial started with participants performing a warm-up of a 1000 m swim, followed by a maximal 200 m front-crawl swim test.…”

SERCA function is impaired in skeletal and cardiac muscles from young DBA/2J mdx mice

“…Serum creatine kinase activity was determined as previously described (42), with a M2 -bound Indo-1) and 485 nm (Ca 2+ -free Indo-1). After the plateau was reached, 1 µl of cyclopiazonic acid (CPA) was added to inhibit the SERCA pump and initiate SR Ca 2+ leak.…”