THE EFFECTS OF BICYCLE FRAME GEOMETRY ON MUSCLE ACTIVATION AND POWER DURING A WINGATE ANAEROBIC TEST

The purpose of this study was to compare the effects of bicycle seat tube angles (STA) of (72 ° and 82°) on power production and EMG of the vastus laeralis (VL), vastus medialis (VM), semimembranous (SM), biceps femoris (BF) during a Wingate test (WAT). Twelve experienced cyclists performed a WAT at each STA. Repeated measures ANOVA was used to identify differences in muscular activation by STA. EMG variables were normalized to isometric maximum voluntary contraction (MVC). Paired t-tests were used to test the effects of STA on: peak power, average power, minimum power and percent power drop. Results indicated BF activation was significantly lower at STA 82 ° (482.9 ± 166.6 %MVC·s) compared to STA 72 ° (712.6 ± 265.6 %MVC·s). There were no differences in the power variables between STAs. The primary finding was that increasing the STA from 72 ° to 82 ° enabled triathletes ’ to maintain power production, while significantly reducing the muscular activation of the biceps femoris muscle