Author(s): DEGUCHI, M., HOMMA, H., DE ALMEIDA, K., SAITO, M., KOZUMA, A., TSUCHIYA, Y., KOZAKI, K., OCHI, E., OKAMOTO, T., NAKAZATO, K., KIKUCHI, N., Institution: GRADUATE SCHOOL OF NIPPON SPORTS SCIENCE UNIVERSITY, Country: JAPAN, Abstract-ID: 842

INTRODUCTION:
Previously, it has been reported that torque loss immediately after the eccentric exercise reflects the peak of creatin kinase (CK) and other muscle damage response that occurs in the following few days (Nosaka et al., 2006). However, the association between torque changes during eccentric exercise on muscle damage responses at the recovery period, including inflammation response (IL-6, etc.), is unknown. The purpose of present study is to investigate the association between the recovery of muscle damage and changes in torque of maximal eccentric exercise.
METHODS:
A total of 95 participants (age: 22.2±2.5 years), including 50 men and 45 women, who had not history of participation in daily resistance exercise of biceps, were enrolled in the study. Participants performed five sets of six maximal eccentric elbow flexion exercises. Maximum voluntary contraction torque (MVC), range of motion (ROM), muscle soreness, serum CK and interleukin-6 (IL-6) concentration were assessed immediately before and after, as well as 1, 2, 3, and 5 days after eccentric exercise. The torque loss (TL2, TL3, TL4, TL5) in sets 2-5 relative to the first set of eccentric exercises was also calculated. Furthermore, deviations were calculated from MVC, ROM, muscle soreness, CK and IL-6 after 5 days of exercise, respectively, and averaged to calculate the Total DV.
RESULTS:
Multiple regression analysis using MVC and TL2, 3, 4, 5 immediately after eccentric exercise as a model significantly predicted MVC, ROM, CK, IL-6 and Total DV in the recovery period (after 5 days of exercise) (MVC: 50.3%, ROM: 8.9%, CK: 22.1%, IL-6: 7.9%, Total DV: 32.2%, p<0.05). The predicted probability of each muscle damage response during recovery period was higher than immediately after MVC only (+4.3%, +1.2%, +2.4%, +4.1% and +5.3% respectively compared to MVC only). These results suggest that the assessment of performance changes during exercise may contribute to more accurate prediction of the response at the recovery period.
CONCLUSION:
The use of torque loss during exercises in combination with torque loss after the eccentric exercises allowed a more detailed prediction of the recovery process of the muscle damage response.