The physiological and perceptual demands of running on a curved non-motorised treadmill: Implications for self-paced training

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% Math EqO2max was elicited. Design & methods 13 trained male runners (mean ± SD; 36 ± 11 years, 1.80 ± 0.06 m, 70 ± 4 kg, Math EqO2max: 57.3 ± 3.5 mL kg−1 min−1) performed an incremental running test on a MT to determine Math EqO2max and the accompanying maximum velocity (Vmax). Participants first completed a familiarization session on the cNMT. Next, participants ran for 4 min 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 4 min run at 80% Vmax on the cNMT. Running on the cNMT elicit a higher relative oxygen uptake (%Math EqO2max) 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% Math EqO2max 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% Math EqO2max 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.