TEST-RETEST RELIABILITY OF SELECTED ERGOMETER GRINDING PERFORMANCE MEASURES

Abstract

Reliability of grinding performance on a custom-built ergometer was assessed using 18 highly trained America’s Cup sailors. Sixteen grinding conditions varied by load, deck heel (tilt), and grinding direction (forward or backward) were examined. Performance measures were peak power (W) and external work over five seconds (kJ). Statistics were difference in mean (Mdiff), standard error of measurement (SEM) and intra-class correlation coefficients (ICC). External work (SEM = 1.6-6.9%; ICC = 0.91-0.99) was more reliable than peak power (SEM = 1.3-9.6%; ICC = 0.84-0.99). Performance was more consistent when varied by load than by heel condition, and was most reliable in lighter load conditions. Within heel conditions, downhill-uphill tilt was more reliable than right-left tilt. Grinding direction did not appear to affect performance reliability.