Recovery of Strength After Exercise-Induced Muscle Damage in Vegetarians Consuming the Upper and Lower Ends of Protein Recommendations for Athletes

TL;DR

This study found that vegetarian athletes recovering from muscle damage experienced similar strength and soreness recovery whether they consumed lower or upper protein recommendations.

Contribution

The study compares recovery outcomes of vegetarian athletes consuming different protein amounts, addressing gaps in plant-based protein recommendations.

Findings

No significant difference in strength recovery between lower and upper protein intake groups.

No significant difference in muscle soreness recovery between the two protein conditions.

Both protein levels supported similar recovery of power and pain thresholds after muscle damage.

Abstract

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.

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