Search

The step-ramp-step (SRS) can assign constant-load exercise intensities from a ramp-incremental test. Its precision using different moderate-intensity (MOD) steps or ramp slopes has yet to be evaluated. Purpose: To assess whether: i) a lower amplitude constant-load MOD is appropriate to determine the mean response time (MRT); ii) the method accurately corrects the dissociation in the ...O2-PO relationship during ramp compared with constant-load exercise when using different ramp slopes. Methods: Eighteen participants (7 females) performed three SRS tests including: i) step-transitions into MOD from 20 to 50 W (MOD50) and 80 W (MOD80); and ii) slopes of 15, 30, and 45 W⋅min-1. The ...O2 and PO at the gas exchange threshold (GET) and the corrected respiratory compensation point (RCPCORR) were determined. Two to three 30-min constant-load trials evaluated the ...O2 and PO at the maximal metabolic steady state (MMSS). Results: There were no differences in ...O2 at GET (1.97 ±0.36,1.99 ±0.36, 1.95 ±0.30 L⋅min-1), andRCP (2.81 ±0.57,2.86± 0.59,2.84 ±0.59) between 15,30, and 45 W⋅min-1 ramps, respectively (P >0.05). The MRT in seconds was not affected by the amplitude of the MOD or the slope of the ramp (range 19 ± 10 s to 23 ± 20 s; P > 0.05). The mean PO at GET was not significantly affected by the amplitude of the MOD or the slope of the ramp (range 130 ± 30 W to 137 ± 30 W; P > 0.05). The PO at RCPCORR was similar for all conditions ((range 186 ± 43 W to 193 ± 47 W; P > 0.05). Conclusions: The SRS protocol accounts for the ...O2 MRT when using smaller amplitude steps, and for the ...O2 slow component when using different ramp slopes, allowing for accurate partitioning of the exercise intensity domains in a single test. [ABSTRACT FROM AUTHOR]

Introduction: This study assessed the effect of individualized, domain-based exercise intensity prescription on changes in maximal oxygen uptake (V̇O 2max ) and submaximal thresholds., Methods: Eighty-four young healthy participants (42 females, 42 males) were randomly assigned to six age, sex, and V̇O 2max -matched groups (14 participants each). Groups performed continuous cycling in the 1) moderate (MOD), 2) lower heavy (HVY1), and 3) upper heavy-intensity (HVY2) domain; interval cycling in the form of 4) high-intensity interval training (HIIT) in the severe-intensity domain, or 5) sprint-interval training (SIT) in the extreme-intensity domain; or no exercise for 6) control (CON). All training groups, except SIT, were work-matched. Training participants completed three sessions per week for 6 wk with physiological evaluations performed at PRE, MID, and POST intervention., Results: Compared with the change in V̇O 2max (∆V̇O 2max ) in CON (0.1 ± 1.2 mL·kg -1 ·min -1 ), all training groups, except MOD (1.8 ± 2.7 mL·kg -1 ·min -1 ), demonstrated a significant increase ( P < 0.05). HIIT produced the highest increase (6.2 ± 2.8 mL·kg -1 ·min -1 ) followed by HVY2 (5.4 ± 2.3 mL·kg -1 ·min -1 ), SIT (4.7 ± 2.3 mL·kg -1 ·min -1 ), and HVY1 (3.3 ± 2.4 mL·kg -1 ·min -1 ), respectively. The ΔPO at the estimated lactate threshold ( θLT ) was similar across HVY1, HVY2, HIIT, and SIT, which were all greater than CON ( P < 0.05). The ΔV̇O 2 and ΔPO at θLT for MOD was not different from CON ( P > 0.05). HIIT produced the highest ΔPO at maximal metabolic steady state, which was greater than CON, MOD, and SIT ( P < 0.05)., Conclusions: This study demonstrated that i) exercise intensity is a key component determining changes in V̇O 2max and submaximal thresholds and ii) exercise intensity domain-based prescription allows for a homogenous metabolic stimulus across individuals., (Copyright © 2024 by the American College of Sports Medicine.)