Influence of Protein Supplement on the Process of Rehabilitation in Damage of Muscles Caused by Physical Loads

Abstract

Resistance exercise is a common mode of training may precipitate temporary exercise-induced muscle damage that manifests as a reduction in neuromuscular function, reduced range of motion, increased muscle soreness, limb swelling and the elevation of intramuscular proteins in blood. The purpose of this study was to study the effect of protein supplements on the process of rehabilitation for muscle injuries caused by physical stress. The study involved 21 clinically healthy men. Participants perform eccentric contractions of the quadriceps femoris muscle. All participants in the studies were randomly assigned to three groups. The first group received the protein supplement before exercise and placebo after the load. The second group received a placebo before the load and a protein drink after. The third group received a placebo both before and after the load. Before the load and 24, 48, 72 hours after the load, the maximum possible reduction (MPR) of the quadriceps muscle was studied, the severity of muscle soreness (MS), the content of creatine kinase (CK) in the serum. The dynamics of changes in the studied indicators was unidirectional in all groups. The index of the maximum possible reduction reached a minimum value 24 hours after exercise and gradually returned to the initial values in 72 hours. Between the first group and the control group no significant differences were found in any of the stages of restitution. At the same time, there was a significant difference in recovery in the participants of the second group and the control group at 48 hours after the load (94 ± 3.81 and 84 ± 3.12, P <0.05), which indicates a faster recovery of contractile ability of the muscles in the studied persons of second group. Just as in the study of MPR dynamics, there were no significant differences between the indices of participants in the first and control groups. In the case of participants in the third group, significant differences in indices are determined in the intervals 48 and 72 hours after the load. The peak values of CK recorded 48 hours after the load. Significant differences were found between second group and control (1448 ± 208 and 864 ± 113, P <0.05). Consequently the intake of protein supplements immediately after physical exertion reduces the duration of the subjective sensation of muscle soreness and promotes the fastest regeneration of damaged muscle fibers.