Comparison of critical speed determined from track running and treadmill tests in elite runners.

The purpose of this study was to compare critical speed determined from a field test of maximal effort runs between 3 and 15 min on a running track and a laboratory test of high-speed runs on a treadmill with a 10-km criterion performance. Nine highly trained male runners (VO ++(2max) 67.7 +/- 4.1 ml*kg*min(-1)) participated in the study. Critical speed was determined from three maximal runs (907, 2267.5, and 4081.5 m) on a 453.5-m indoor running track and from three high speed runs on a treadmill. The treadmill speeds were individualized so that exhaustion was reached in approximately 3, 7, and 13 min. All subjects participated in a 10-km cross-country race (measured distance 9.8 km) on a flat and dry course. Track critical speed (293 m*min(-1)) was correlated (r = 0.92, P < 0.001) with race speed (293 m*min(-1)), whereas treadmill critical speed (300 m*min(-1)) had the same correlation but over predicted race performance. It was concluded that although both tests were correlated with 9.8-km race performance, track-determined critical speed was easy to administer with highly trained runners and was very similar to 10-km race speed.