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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]

Via the identification of the ramp-specific gas exchange threshold (GET) and respiratory compensation point (RCP), the recently validated step--ramp--step (SRS) protocol enables the prediction of the power outputs at the lactate threshold and maximal metabolic steady state. Purpose: We aimed to test the extended capabilities of the SRS protocol by validating its capacity to predict the power outputs for targeted metabolic rates (VO2) and time-to-task failure (Tlim) within the heavy- and severe-intensity domain, respectively. Methods: Fourteen young individuals completed (i) an SRS protocol from which the power outputs at GET and RCP (RCPCORR), and the work accruable above RCPCORR, defined as WRAMP, were derived; (ii) one heavy-intensity bout at a power output predicted to elicit a targeted VO2 equidistant from GET and RCP; and (iii) four severe-intensity trials at power outputs predicted to elicit targeted Tlim at minutes 2.5, 5, 10, and 13. These severe-intensity trials were also used to compute the constant-load--derived critical power and W´ (WCONSTANT). Results: Targeted (2.41 ± 0.52 L·min-1) and measured (2.43 ± 0.52 L·min-1) VO2 at the identified heavy-intensity power output (162 ± 43 W) were not different (P = 0.71) and substantially concordant (CCC = 0.95). Likewise, targeted and measured Tlim for the four identified severe-intensity power outputs were not different (P > 0.05), and the aggregated coefficient of variation was 10.7% ± 8.9%. The derived power outputs at RCPCORR (192 ± 53W) and critical power (193 ± 53 W) were not different (P = 0.65) and highly concordant (CCC = 0.99). There were also no differences between WRAMP and WCONSTANT (P = 0.51). Conclusions: The SRS protocol can accurately predict power outputs to elicit discrete metabolic rates and exercise durations, thus providing, with time efficiency, a high precision for the control of the metabolic stimulus during exercise. [ABSTRACT FROM AUTHOR]

Introduction: This study assessed the effect of individualized, domain-based exercise intensity prescription on changes in maximal oxygen uptake (...) and submaximal thresholds. Methods: Eighty-four young healthy participants (42 females, 42males) were randomly assigned to six age, sex, and ...-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 ... (...) in CON (0.1 ± 1.2 mL⋅kg-1⋅min-1), all training groups, exceptMOD (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 ... 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 ... and submaximal thresholds and ii) exercise intensity domain-based prescription allows for a homogenous metabolic stimulus across individuals. [ABSTRACT FROM AUTHOR]