摘要
Bergstrom, HC, Housh, TJ, Cochrane, KC, Jenkins, NDM, Buckner, SL, Goldsmith, JA, Zuniga, JM, Schmidt, RJ, Johnson, GO, and Cramer, JT. Application of the critical heart model to treadmill running. J Strength Cond Res 29(8): 2237-2248, 2015The mathematical model used to estimate critical power has been applied to heart rate (HR) measurements during cycle ergometry to derive a fatigue threshold called the critical heart rate (CHR). This study had 2 purposes: (a) determine if the CHR model for cycle ergometry could be applied to treadmill running and (b) examine the times to exhaustion (T-lim) and the V.o(2) responses during constant HR runs at the CHR. Thirteen runners (mean +/- SD; age = 23 +/- 3 years) performed an incremental treadmill test to exhaustion. On separate days, 4 constant velocity runs to exhaustion were performed. The total number of heart beats (HBlim) for each velocity was calculated as the product of the average 5-second HR and T-lim. The CHR was the slope coefficient of the HBlim vs. T-lim relationship. The T-lim and V.o(2) responses were recorded during a constant HR run at the CHR. Polynomial regression analyses were used to examine the patterns of responses for V.o(2) and velocity. The HBlim vs. T-lim relationship (r(2) = 0.995-1.000) was described by the linear equation: HBlim = a + CHR (T-lim). The CHR (176 +/- 7 bmin(-1), 91 +/- 3% HRpeak) was maintained for 47.84 +/- 11.04 minutes. There was no change in HR but quadratic decreases in velocity and V.o(2). These findings indicated that the CHR model for cycle ergometry was applicable to treadmill running and represented a sustainable (30-60 minutes) intensity but cannot be used to demarcate exercise intensity domains.
- 出版日期2015-8