Physiological responses to training using PowerCranks on trained cyclists.
Stephen J. Dixon, Michael F. Harrison, Kenneth A. Seaman, Stephen S. Cheung and J. Patrick Neary. University of New Brunswick, Fredericton, NB; Dalhousie University, Halifax, NS; University of Regina, Regina, SK
PowerCranks are cycling cranks that are independent of each other, requiring force application throughout the pedal stroke, theoretically increasing muscle recruitment and stimulus in the legs. This study examined the physiological adaptations to PowerCranks, and the time course of responses in maximal and submaximal cycling performance. Eight Trained cyclists (35.1 ± 6.8 yr) participated in 6 wks of 100% immersion training using solely PowerCranks, consisting of ~8 h/wk of aerobic and anaerobic (~80:20) cycling training. A continuous incremental cycling test to exhaustion (50 W increase every 2 min) was performed prior to and following the training program using normal cranks. In addition, 10 min of submaximal cycling (70% of VO2max wattage) were performed with both normal cranks and PowerCranks at an approximate cadence of 85 rpm, pre and post training. VO2max increased 15.6% (58.1 ± 5.8 to 67.3 ± 6.6, P=0.013). Maximum power increased 11.6% (316.7 ± 25.8 to 358.3 ± 20.4, P=0.011) following PowerCranks training. In summary, our data suggest that PowerCranks increased maximal aerobic capacity and power in trained cyclists. Supported by NSERC
Oral presentation at Canadian Society of Exercise Physiologists meeting, November 2006. unpublished.
COMMENT: We were surprised that such a large improvement, especially in VO2 max, could be documented in such a short period of time. Although, in hindsight, this is quite plausible as newly exercised muscles should be starting to show substantial aerobic adaption within 4-6 weeks and most users are well past the coordination adaption period in this time. If you are using more muscle when you exercise your VO2 max should be higher. It is that simple. PowerCranks simply force the cyclist to use more muscles than they ordinarily do when cycling.