The effects of betalain-rich concentrate supplementation in attenuating muscle damage following eccentric exercise

Abstract

Betalains are bioactive pigments that have been shown to reduce muscle damage and enhance recovery from exercise. However, to date, studies have examined the effects of betalains on aerobic exercise alone, and thus, their possible benefits for muscle damage recovery following eccentric exercise is unknown. We, therefore, aimed to examine the effects of a betalain-rich concentrate (BRC) on indices of muscle damage following eccentric exercise. Eleven healthy, recreationally active males were randomly assigned into a treatment group (50 mg of BRC, containing 12.5 mg of betalains, 3 times per day for 3 days) or a control group and performed 30 maximal eccentric contractions of the elbow flexors. Maximal voluntary contraction (MVC), arm circumference (AC), muscle soreness (MS), and range of motion (ROM) were measured before, immediately after, and 24, 48, and 72 hr following eccentric exercise. Creatine kinase (CK) was measured before, 24, 48, and 72 hr following the eccentric exercise. No significant differences or interactions were observed for any of the variables (p = >. 05); however, a non-significant trend with a large effect size (p =. 07, np2 =. 28) was found for the main effect for MVC. Although we failed to identify any statistically significant differences in any of the variables measured, the large effect size observed for MVC may have practical benefits in the enhancement of skeletal muscle recovery following eccentric exercise.