Abstract
Critical Power (CP) demarcates the boundary between sustainable and unsustainable exercise, and it is widely used as a measure of exercise tolerance/performance. Evaluation typically consists of a time-consuming and physically demanding protocol of 3-5 time-to-exhaustion trials (TTE) ranging from 1 to 20 min. However, the power output (PO) associated with the calculated CP does not always reflect a sustainable intensity of exercise, and lactate concentration ([La]) cannot be stabilized (i.e. lactate steady-state is not reached).
PURPOSE: To test cyclists’ ability to predict their CP based on their own perception of effort, and to compare this PO with those derived from 5 TTE trials and maximal lactate steady-state (MLSS) measurements.
METHODS: Seven experienced cyclists (28±3 yrs; 68.4±7.3 kg; 175±9 cm) participated in the study. A ramp incremental test to exhaustion was performed on a cycle ergometer (Velotron Dynafit Pro, Racer Mate, Seattle, WA, USA) for determination of VO2peak (Quark CPET, Cosmed, Rome, Italy) and peak PO (POpeak). PO of CP from 5 TTE trials was derived from a 2-parameter hyperbolic model (POHYP). Participants also performed two 30-min rides at a self-selected PO (POSELF) that they considered the highest intensity of exercise they could sustain for a prolonged time. Additionally, participants performed 30-min rides at the estimated POHYP for determination of PO at MLSS (POMLSS). [La] was measured at 5-min intervals and POMLSS was considered as the highest PO at which variation of [La] ≤ 1.0 mM·L-1 between the 10th and the 30th min.
RESULTS: Mean VO2PEAK and POPEAK were 4.30±0.67 L·min-1 and 383±53 W, respectively. POHYP, POSELF and POMLSS were similar (267±39 W, 246±37 W and 246±37 W, respectively; p > 0.05). Bland-Altman plots were used to determine limits of agreement (LOA) between POSELF and POMLSS (-22 to 22 W, bias = 0; p > 0.05), POHYP and MLSS (-8 to 51 W, bias = 21; p > 0.05) and POSS and POHYP (-39 to -4 W, bias = -21 W; p > 0.05). Although POSELF and POHYP had similar magnitudes of range when compared to POMLSS, POHYP consistently over predicted POSELF and POMLSS.
CONCLUSION: Experienced cyclists can predict their maximal sustainable PO for a prolonged time-trial with more precision than the current CP testing. This finding challenges the practical application of this test in experienced cyclists.
PURPOSE: To test cyclists’ ability to predict their CP based on their own perception of effort, and to compare this PO with those derived from 5 TTE trials and maximal lactate steady-state (MLSS) measurements.
METHODS: Seven experienced cyclists (28±3 yrs; 68.4±7.3 kg; 175±9 cm) participated in the study. A ramp incremental test to exhaustion was performed on a cycle ergometer (Velotron Dynafit Pro, Racer Mate, Seattle, WA, USA) for determination of VO2peak (Quark CPET, Cosmed, Rome, Italy) and peak PO (POpeak). PO of CP from 5 TTE trials was derived from a 2-parameter hyperbolic model (POHYP). Participants also performed two 30-min rides at a self-selected PO (POSELF) that they considered the highest intensity of exercise they could sustain for a prolonged time. Additionally, participants performed 30-min rides at the estimated POHYP for determination of PO at MLSS (POMLSS). [La] was measured at 5-min intervals and POMLSS was considered as the highest PO at which variation of [La] ≤ 1.0 mM·L-1 between the 10th and the 30th min.
RESULTS: Mean VO2PEAK and POPEAK were 4.30±0.67 L·min-1 and 383±53 W, respectively. POHYP, POSELF and POMLSS were similar (267±39 W, 246±37 W and 246±37 W, respectively; p > 0.05). Bland-Altman plots were used to determine limits of agreement (LOA) between POSELF and POMLSS (-22 to 22 W, bias = 0; p > 0.05), POHYP and MLSS (-8 to 51 W, bias = 21; p > 0.05) and POSS and POHYP (-39 to -4 W, bias = -21 W; p > 0.05). Although POSELF and POHYP had similar magnitudes of range when compared to POMLSS, POHYP consistently over predicted POSELF and POMLSS.
CONCLUSION: Experienced cyclists can predict their maximal sustainable PO for a prolonged time-trial with more precision than the current CP testing. This finding challenges the practical application of this test in experienced cyclists.
| Original language | English |
|---|---|
| Pages (from-to) | 707-707 |
| Number of pages | 1 |
| Journal | Medicine and Science in Sports and Exercise |
| Volume | 48 |
| Issue number | 5 |
| DOIs | |
| Publication status | Published - 3 Jun 2016 |
| Externally published | Yes |
| Event | Annual Meeting of the American-College-of-Sports-Medicine (ACSM) - Boston, Morocco Duration: 31 May 2016 → 4 Jun 2016 |