Abstract
The “step-ramp-step” (SRS) protocol improves domain-based exercise intensity prescription in cycling by adjusting the ramp-exercise oxygen uptake (V̇O2) versus work-rate relationship for V̇O2 kinetics and muscle-lung circulatory delay.
PURPOSE: This study investigated whether similar corrections are required in running by comparing the accuracy of a treadmill-based SRS protocol with the “classic” (unadjusted) linear approach to predict domain-specific V̇O2 responses.
METHODS: Five healthy males (age: 26 ± 9 years) performed a ramp-incremental test (0.6 km·h-1·min-1) from 6 km·h-1 to task failure followed by two constant-speed bouts within the moderate- (MOD - below estimated lactate threshold; LT) and heavy-intensity domains (HVY - between LT and respiratory compensation point; RCP). The V̇O2 at LT and RCP were visually identified by plotting standard breath-by-breath ventilatory and gas exchanges measurements against ramp V̇O2. Then, the corresponding speed at LT and RCP, derived from the unadjusted linear V̇O2-speed relationship from the ramp exercise (“classic” linear approach), were used to establish two domain-specific constant-speed bouts at 50% between: i) baseline and LT (ΔMOD); and ii) LT and RCP (ΔHVY). Constant-speed bouts were performed on separate days, and “measured” end-exercise V̇O2 was compared to “predicted” V̇O2 using a: i) “SRS-corrected” (where MOD and HVY bouts were used to adjust the ramp V̇O2-speed relationship); and ii) unadjusted V̇O2-speed relationship from ramp exercise.
RESULTS: The treadmill speeds for ΔMOD, and ΔHVY were 8.1 ± 1.2 and 11.4 ± 2.0 km·h-1, respectively, eliciting end-exercise V̇O2 responses of 2.19 ± 0.28 and 2.81 ± 0.26 L·min-1. The measured end-exercise V̇O2 were not different compared to SRS-predicted V̇O2 at ΔMOD (mean difference: -0.04 ± 0.19 L·min-1; p = 0.70) and ΔHVY (0.08 ± 0.30 L·min-1; p = 0.57). Compared to the classic-predicted V̇O2, the measured end-exercise V̇O2 was not different from predicted for ΔMOD (0.15 ± 0.15 L·min-1; p = 0.09) but was higher for ΔHVY (0.19 ± 0.14 L·min-1; p = 0.04).
CONCLUSION: In healthy individuals, the SRS protocol provides more accurate V̇O2 response predictions than the “classic” linear approach and potentially represents a better alternative for domain-based exercise-intensity prescriptions. Supported by NSERC
PURPOSE: This study investigated whether similar corrections are required in running by comparing the accuracy of a treadmill-based SRS protocol with the “classic” (unadjusted) linear approach to predict domain-specific V̇O2 responses.
METHODS: Five healthy males (age: 26 ± 9 years) performed a ramp-incremental test (0.6 km·h-1·min-1) from 6 km·h-1 to task failure followed by two constant-speed bouts within the moderate- (MOD - below estimated lactate threshold; LT) and heavy-intensity domains (HVY - between LT and respiratory compensation point; RCP). The V̇O2 at LT and RCP were visually identified by plotting standard breath-by-breath ventilatory and gas exchanges measurements against ramp V̇O2. Then, the corresponding speed at LT and RCP, derived from the unadjusted linear V̇O2-speed relationship from the ramp exercise (“classic” linear approach), were used to establish two domain-specific constant-speed bouts at 50% between: i) baseline and LT (ΔMOD); and ii) LT and RCP (ΔHVY). Constant-speed bouts were performed on separate days, and “measured” end-exercise V̇O2 was compared to “predicted” V̇O2 using a: i) “SRS-corrected” (where MOD and HVY bouts were used to adjust the ramp V̇O2-speed relationship); and ii) unadjusted V̇O2-speed relationship from ramp exercise.
RESULTS: The treadmill speeds for ΔMOD, and ΔHVY were 8.1 ± 1.2 and 11.4 ± 2.0 km·h-1, respectively, eliciting end-exercise V̇O2 responses of 2.19 ± 0.28 and 2.81 ± 0.26 L·min-1. The measured end-exercise V̇O2 were not different compared to SRS-predicted V̇O2 at ΔMOD (mean difference: -0.04 ± 0.19 L·min-1; p = 0.70) and ΔHVY (0.08 ± 0.30 L·min-1; p = 0.57). Compared to the classic-predicted V̇O2, the measured end-exercise V̇O2 was not different from predicted for ΔMOD (0.15 ± 0.15 L·min-1; p = 0.09) but was higher for ΔHVY (0.19 ± 0.14 L·min-1; p = 0.04).
CONCLUSION: In healthy individuals, the SRS protocol provides more accurate V̇O2 response predictions than the “classic” linear approach and potentially represents a better alternative for domain-based exercise-intensity prescriptions. Supported by NSERC
| Original language | English |
|---|---|
| Pages (from-to) | 39-39 |
| Number of pages | 1 |
| Journal | Medicine and Science in Sports and Exercise |
| Volume | 55 |
| Issue number | 9 |
| Publication status | Published - Sept 2023 |
| Externally published | Yes |
| Event | Annual Meeting of the American-College-of-Sports-Medicine (ACSM) - Denver, Colombia Duration: 30 May 2023 → 2 Jun 2023 |