LAUSR

OBJECTIVES To compare physiological and perceptual response of running on a curved non-motorized treadmill (cNMT) with running on a motorized treadmill (MT), and to determine the running velocity at which a physiological response≥90% V˙O2max was elicited. DESIGN & METHODS 13 trained male runners (mean±SD; 36±11years, 1.80±0.06m, 70±4kg, V˙O2max: 57.3±3.5 mLkg-1min-1) performed an incremental running test on a MT to determine V˙O2max and the accompanying maximum velocity (Vmax). Participants first completed a familiarization session on the cNMT. Next, participants ran for 4min at five/six progressively higher velocities (40-90% Vmax). These runs were completed on the cNMT and MT in two separate visits in a randomized and counterbalanced order. RESULTS No participant was able to complete the 4min run at 80% Vmax on the cNMT. Running on the cNMT elicit a higher relative oxygen uptake (%V˙O2max) across all velocities compared to the MT (32.5±5%, p<0.001, ES 3.3±0.9), and was accompanied by significantly higher heart rates (16.8±3%, p<0.001, ES 3.4±1.5), an altered cadence (2.6±0.7%, p<0.001, ES 0.8±0.3) and ratings of perceived exertion (27.2±5%, p<0.001, ES 2.3±0.6). A less efficient running economy was evident when running on the cNMT (+38.4±16%, p<0.001, ES 2.73). Individual (n=9) linear interpolation predicted an exercise intensity of 90% V˙O2max was achieved in the non-motorized condition when running at 62.1±3.5% Vmax (R2=0.986±0.01), which was lower than MT run in which 90% V˙O2max was achieved at 81.4±5.6% Vmax (R2=0.985±0.02; 29.8±8%, p<0.001, ES 3.87). CONCLUSIONS Running on the cNMT has higher physiological and perceptual demands and increases cadence.