Effect of inclination on the results of the maximal anaerobic running test.

This study investigated the effect of treadmill inclination on the maximal anaerobic running test (MART). Ten male subjects ran a 20-m speed test on a track to determine the maximal running velocity (V20m) and performed three MARTs at the grades of 1 degree, 4 degrees and 7 degrees in a random order. Each MART included n 20-s sprints at gradually increased velocity and counter-movement jumps (CMJ) which were performed before and after the exhausting sprints. At each grade, the power (oxygen demand) of the sprints was determined by extrapolating the individual steady state oxygen uptake of three submaximal running velocities measured separately at the corresponding grades. Maximal power (Pmax), power at 10mM (P10mM) and 5 mM (P5mM) blood lactate levels as well as peak blood lactate concentration (peak BLa) were determined at each MART. The Pmax increased from 94.1 +/- 8.8 and 110.0 +/- 10.2 to 119.5 +/- 8.0 ml.kg-1.min-1 when the treadmill inclination increased from 1 degree and 4 degrees to 7 degrees, respectively (p < 0.001). P10mM and P5mM also increased with the inclination (p < 0.001). Correlation coefficients of the Pmax with CMJrest and V20m were 0.77 and 0.69 at the grade of 1 degree, 0.75 and 0.59 at the grade of 4 degrees, and 0.62 and 0.42 at the grade of 7 degrees, respectively. The increased peak BLa (p < 0.01) with the treadmill inclination suggests that lactic capacity was not completely used at the grades of 1 degree and 4 degrees. In conclusion, the maximal power increased with the grade of uphill running in the MART. Furthermore, the present results suggest that the importance of force and velocity components of the neuromuscular system decreased and the importance of metabolic component increased with the increased grade of the uphill running.