Influence of Post-Occlusive Reactive Hyperemia on Muscle Performance and Oxygen Recovery

PURPOSE: To examine the influence of temporary occlusion of the arm, prior to exercise, on muscle performance, O2 utilization and recovery. METHODS: 18 healthy, male and female individuals, in the ages ranging from 18 to 24 years, participated in the study. After familiarization of the protocol, each subject performed two isometric handgrip exercises to exhaustion under two different conditions. Under one condition (CON), subjects performed isometric handgrip exercise to exhaustion using a handgrip dynamometer. Under another condition, the exercising arm was occluded for two minutes (at 100 mmHg above the subject's systolic blood pressure) followed by 90 seconds of recovery prior to the same handgrip exercise (RH). All handgrip exercises were performed at 30% of the subject's maximal voluntary contraction (MVC) and each exercise condition was separated by a minimum of 1 week. The order of the exercise was randomized. Exercise was stopped when the subject could not maintain 30% of their MVC for more than 3 seconds. Muscular performance was determined as the amount of time (in seconds) subjects sustained 30% of MVC. For both conditions, near infrared spectroscopy (NIRS) was used to determine local muscle HbO2 utilization during exercise as well as HbO2 recovery after exercise. A paired t-test was performed to determine differences. RESULTS: There was no significant difference in exercise time between the two conditions. However, when stratified by gender, women exhibited greater exercise time after RH condition when compared to men (212.43 ± 92 vs. 144.64 ± 31.8 sec; p<0.05). Subsequently, a trend of greater muscle deoxygenation was shown during RH condition when compared to CON condition (69.2 ± 10.3 vs. 60.2 ± 18.7 % respectively). Furthermore, muscle reoxygenation rate (T50) after exercise revealed a significant difference between the two conditions (CON: 14.06 ± 6.2 vs. RH: 19.90 ± 6.2 sec; p <.04). CONCLUSIONS: The results of this study suggest that influence of reactive hyperemia may be gender specific, a condition that may be explained by differences in capillary bed, O2 utilization and recovery during and after exercise.