Objective: The present study compares the effect of ingesting hydrolyzed beef protein, whey protein, and carbohydrate on performance, body composition (via plethysmography), muscular thickness, and blood indices of health, including ferritin concentrations, following a 10-week intervention program.
Methods: After being randomly assigned to one of the following groups-beef, whey, or carbohydrate-24 master-age (35-60 years old) male triathletes (n = 8 per treatment) ingested 20 g of supplement mixed with plain water once a day (immediately after training or before breakfast). All measurements were performed pre- and postinterventions.
Results: Only beef significantly reduced body mass (p = 0.021) along with a trend to preserve or increase thigh muscle mass (34.1 ± 6.1 vs 35.5 ± 7.4 mm). Both whey (38.4 ± 3.8 vs 36.9 ± 2.8 mm) and carbohydrate (36.0 ± 4.8 vs 34.1 ± 4.4 mm) interventions demonstrated a significantly (p < 0.05) decreased vastus medialis thickness Additionally, the beef condition produced a significant (p < 0.05) increase in ferritin concentrations (117 ± 78.3 vs 150.5 ± 82.8 ng/mL). No such changes were observed for the whey (149.1 ± 92.1 vs 138.5 ± 77.7 ng/mL) and carbohydrate (149.0 ± 41.3 vs 150.0 ± 48.1 ng/mL) groups. Furthermore, ferritin changes in the beef group were higher than the modification observed in whey (p < 0.001) and carbohydrate (p = 0.025) groups. No differences were found between whey and carbohydrate conditions (p = 0.223). No further changes were observed.
Conclusion: Ingesting a hydrolyzed beef protein beverage after workout or before breakfast (nontraining days) can be effective in preserving thigh muscle mass and in improving iron status in male master-age triathletes.
Keywords: Endurance athletes; diet; ferritin; iron; maltodextrin; meat; muscle thickness.