Agradecimentos: We would like to thank FAPESP (protocol no. 2009/08535-5, 2012/06355-2 and 2013/16710-7), CNPq (protocol no. 461559/2014-5) and CAPES (protocol no. 001) for their funding in this study. We also want to thank all colleagues at the Laboratory of Applied Sports Physiology. Te English text of this paper has been revised by Sidney Pratt, Canadian, MAT (Te Johns Hopkins University), RSAdip—TESL (Cambridge University) Ver menos

Abstract: This study aimed to test the agreement of the incremental test’s physiological responses between tethered running on a nonmotorized treadmill (NMT) to matched relative intensities while running on a conventional motorized treadmill (MT). Using a within-subject crossover design, nine male recreational runners (age = 22 ± 5 years; height = 175 ± 6 cm; weight = 68.0 ± 16.6 kg) underwent two test sessions: one was an incremental intensity protocol on an MT; the other was on an instrumented NMT. Intensity thresholds at V?O2max, respiratory compensation point (iRCP), and lactate threshold (iLT) were registered for analysis, together with V??O2, V??E, ƒR, and blood lactate concentration ([Lac]). Comparisons were based on hypothesis testing (Student’s T-test), effect sizes (Cohen’s d), ICC, and Bland Altman analysis. Statistical significance was accepted at p < 0.05. Attained V?O2max (MT = 52.2 ± 7.3 mL·kg?¹·min?¹ vs NMT = 50.1 ± 8.1 mL·kg?¹·min?¹) and V??O2 at iRCP (MT = 46.3 ± 7.2 mL·kg?¹·min?¹ vs NMT = 42.8 ± 9.3 mL·kg?¹·min?¹) were not different between ergometers (p = 0.15 and 0.13, respectively), with significant ICCs (0.84 and 0.70, respectively) and Pearson’s correlations (r = 0.87 and 0.76, respectively). The [Lac] at iLT presented poor agreement between conditions. Significant correlations were found (r between 0.72 and 0.83) for relative power values of iV?O2max (6.56 ± 1.28 W·kg?¹), iRCP (4.38 ± 1.50 W·kg?¹), and iLT (4.15 ± 1.29 W·kg?¹) related to their counterpart obtained on MT. Results show that running on an NMT offers a higher glycolytic demand under the same relative internal load as running on an MT but with a similar aerobic response and correlated intensity determination Ver menos