Effect of 12 Weeks Training on Fatigue-Induced Postural Sway in Volleyball Players

Abstract

A positive correlation exists between balance ability and athletic performance in several sports. Further, research reveals that muscular fatigue impairs both postural stability and balance. PURPOSE: To determine if 12 weeks of balance training will improve postural control following fatigue-induced exercise in female volleyball players. METHODS:Two professional volleyball teams from Turkish 2nd league were randomly divided into two experimental groups: 1) Balance training group (N= 12; age 21.8±3.7 years); and 2) Control group (N =11; age 20.4±3.5 years). Subjects assigned to the balance training group added 12 weeks of balance training to their normal exercise training program whereas the control group performed only their normal exercise routine. Prior to beginning the balance training, all subjects were familiarized with the balance assessment system and on a separate day, all subjects performed a treadmill test to exhaustion (Bruce protocol). Balance test measures were performed immediately following the exhaustive exercise and at 10, 20, and 30 minutes post exercise. Following 12 weeks of balance training, all subjects then performed another treadmill to exhaustion and balance test measurements were repeated. The balance tests measured the anteroposterior (AP), mediolateral (ML) and total (T) postural sway. Data were analyzed as a two-way factorial repeated measures design using non-parametric statistics. In this method the data were provided as Relative Treatment Effect (RTE). RTE can range between 0 and 1 and if the null hypothesis is accepted, all groups would have a RTE 0.50. RESULTS: Prior to beginning the balance training, exhaustive exercise impaired AP, ML, and T postural sway immediately following exercise in both experimental groups. At the completion of 12 weeks of balance training, exhaustive exercise did not impair postural sway in the trained group at any time period following exercise. In contrast, the control group exhibited impaired postural sway immediately following exhaustive exercise and at 10 and 20 minutes post-exercise. CONCLUSIONS:These findings suggest that balance training can improve fatigue-postural sway instability. Additional research is warranted to determine if training-induced improvement in balance can decrease the risk of injury in selected sports.