Recovery of Strength After Exercise-Induced Muscle Damage in Vegetarians Consuming the Upper and Lower Ends of...

Background/Objective: Plant-based protein is less bioavailable than animal protein. It is unclear if the protein recommendations for athletes should be increased when following a vegetarian diet. This study's purpose is to document the recovery of strength and power, as well as to assess soreness after exercise-induced muscle damage (EIMD), in people following a vegetarian diet while consuming the lower (1.2 g/kg/day) and upper (2.0 g/kg/day) ends of protein recommendations for athletes. Methods: In this crossover design study, subjects were randomly assigned to consume 1.2 or 2.0 g/kg/day of protein and were supplemented up to their allotted amount with pea protein. Sixteen male (n = 9) and female (n = 7) subjects (24 ± 2 yr, 170 ± 7 cm, 68.2 ± 10.0 kg) performed a single-leg vertical jump and maximal isometric and isokinetic knee extension prior to, and five days following, EIMD. The quadricep muscle was injured by completing 10 × 10 eccentric contractions on an isokinetic dynamometer. The opposite condition was performed after a 2-week washout period. Results: There was a difference over time (p < 0.001), but not between conditions, for isometric strength (p = 0.92), vertical jump (p = 0.78), concentric strength at 60 (p = 0.92), 180 (p = 0.91), and 240 degrees per second (p = 0.90). There was a difference over time (p < 0.001), but not between groups, for pressure pain threshold while sitting (p = 0.74) and standing (p = 0.94), and the 10 cm visual analog scale completed while walking (p = 0.10), sitting (p = 0.32), and standing (p = 0.15). Conclusions: There was no difference in recovery of strength, power, and soreness after EIMD in people who follow a vegetarian diet while consuming the lower and upper ends of protein recommendations for athletes.