Article

Determination of Critical Power Using a 3-min All-out Cycling Test

Department of Sport and Exercise Science, University of Wales, Aberystwyth, United Kingdom.
Medicine & Science in Sports & Exercise (Impact Factor: 3.98). 04/2007; 39(3):548-55. DOI: 10.1249/mss.0b013e31802dd3e6
Source: PubMed

ABSTRACT

We tested the hypothesis that the power output attained at the end of a 3-min all-out cycling test would be equivalent to critical power.
Ten habitually active subjects performed a ramp test, two 3-min all-out tests against a fixed resistance to establish the end-test power (EP) and the work done above the EP (WEP), and five constant-work rate tests to establish the critical power (CP) and the curvature constant parameter (W') using the work-time and 1/time models.
The power output in the 3-min trial declined to a steady level within 135 s. The EP was 287 +/- 55 W, which was not significantly different from, and highly correlated with, CP (287 +/- 56 W; P = 0.37, r = 0.99). The standard error for the estimation of CP using EP was approximately 6 W, and in 8 of 10 cases, EP agreed with CP to within 5 W. Similarly, the WEP derived from the 3-min test (15.0 +/- 4.7 kJ) was not significantly different from, and correlated with, W' (16.0 +/- 3.8 kJ; P = 0.35; r = 0.84).
During a 3-min all-out cycling test, power output declined to a stable value in approximately the last 45 s, and this power output was not significantly different from the independently measured critical power.

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    • "The fact that the EP of a 3-min all-out test is higher than the CP or the maximal lactate steady state was previously pointed out by some authors (Bergstrom et al., 2013; Karsten et al., 2014; Sperlich et al., 2011). Notably, our study reported the highest average value of EP (346 W), while other studies showed average EP values ranging from 167 to 312 W (Burnley et al., 2006; Vanhatalo et al., 2007; Sperlich et al., 2011; Bergstrom et al., 2013; Karsten et al., 2014). This further reveals the endurance characteristics of the subjects tested. "
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    ABSTRACT: While the 3-min all-out test is an ideal exercise paradigm to study muscle fatigue during dynamic whole-body exercise, so far it has been used mainly to provide insight into the bioenergetic determinants of performance. To shed some light into the development of peripheral muscle fatigue during the 3-min all-out test, we investigated the time course of muscle-fibre conduction velocity (MFCV). Twelve well-trained cyclists (23 ± 3. yrs) performed an incremental test, a 3-min all-out familiarization trial and a 3-min all-out test. Surface electromyographic signals were detected from the vastus lateralis muscle of the dominant limb. MFCV decreased with power output, though with a somewhat different time course, and the two parameters were strongly correlated (r= 0.87; P < 0.001). A modest decrease in MFCV (17.7 ± 4.8%), probably due to the endurance characteristics of the subjects, may help explain why a relatively high power output (79 ± 8% of the peak power output of the incremental test; 60 ± 14% of the difference between this peak value and the gas exchange threshold) was still maintained at the end of the test. These findings suggest that muscle fatigue substantially affects performance in the 3-min all-out test, expanding on the traditional bioenergetic explanation that performance is limited by rate and capacity of energy supply.
    Full-text · Article · Aug 2015
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    • "Following a standardized warm-up, which included 10 bodyweight squats and 10 alternating lunges, the participant completed 60 seconds of unloaded cycling at 90 rpm, followed by an all-out three-minute effort with resistance being set as a function of pedaling rate (Vanhatalo et al., 2007). Participants were asked to accelerate to approximately 110 rpm over the last 5 s of the baseline period. "
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    ABSTRACT: To evaluate the time course of EMG frequency changes during a three-minute maximal effort cycling test (3MT) session and to examine which parameter between mean (MNF) and median (MDF) frequency is more suitable for evaluation of changes in neuromuscular function throughout a 3MT. Eighteen recreationally-active men volunteered to participate in this study. Maximum voluntary contraction (MVC) was measured using a dynamometer to determine maximal EMG frequency of the vastus lateralis (VL) of the kicking leg during isometric knee extension. A maximal oxygen consumption test (VO2peak) on a cycle ergometer was performed to establish the appropriate load profile for the 3MT which was completed after a period of at least 48 hours. MNF, MDF and power output (PO) values were measured at 10-second epochs throughout the duration of the 3MT. Repeated measures analysis of variance was used to compare the changes in EMG frequency, relative to maximal values from the MVC, and change in PO during the testing procedure. MNF, Root Mean Square (RMS), and PO significantly decreased during the 3MT, while MDF did not change significantly. Statistically, EMG frequency and PO decreased at first and remained constant in response to the 3MT, which may be reflective of differing patterns of muscle fiber type fatigue throughout the testing session. Due to decreased variability, changes in neuromuscular function during this protocol may be better evaluated using MNF than MDF. Key pointsEMG frequency decreased initially and remained constant in response to all-out cycling test.The change in EMG frequency and power output were similar during all-out cycling test.MNF may be better than MDF for neuromuscular function evaluation during all-out cycling test due to decreased variability.
    Full-text · Article · Jun 2015 · Journal of sports science & medicine
    • "Immediately following ramp intolerance, the cycle ergometer was switched to its cadence-dependent (linear) mode and participants were given strong verbal encouragement to quickly accelerate their cadence and deliver a maximal 'sprint' effort. this sprint phase was continued for 3 min to estimate the sprint power (SP); 3 min was chosen on the basis that power output has been previously demonstrated for cycle ergometry to consistently stabilise within this duration (Burnley et al. 2006; Vanhatalo et al. 2007), thus allowing post hoc "
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    ABSTRACT: Purpose The lactate threshold (LT), critical power (CP) and maximum oxygen uptake (\(\dot{V}{\text{O}}_{2\text{max} }\)) together partition exercise intensity domains by their common physiological, biochemical and perceptual response characteristics. CP is the greatest power output attainable immediately following intolerance at \(\dot{V}{\text{O}}_{{2{\text{peak}}}}\), and the asymptote of 3 min all-out exercise. Thus we reasoned that a maximal ‘sprint’ immediately following standard ramp-incremental exercise would allow characterisation of the three aerobic indices in a single test. Methods Ten healthy men (23 ± 3 year, mean ± SD) performed 9 cycle-ergometry tests on different days: (A) two ramp-incremental tests to intolerance (20 W min−1), immediately followed by a 3 min maximal, variable-power effort ramp-sprint test (RST) for LT, \(\dot{V}{\text{O}}_{{2{\text{peak}}}}\) and sprint-phase power (SP) determination; (B) four constant-power tests for CP and \(\dot{V}{\text{O}}_{2\text{max} }\) determination; (C) constant-power tests at 10 W below LT, and 10 W below and above SP to verify intensity domain characterisation. Capillary [lactate] and breath-by-breath \(\dot{V}{\text{O}}_{2}\) were measured. Results Reproducibility of LT, SP and \(\dot{V}{\text{O}}_{2\text{max} }\) measurements between RST repeats was within 5 % or less (r ≥ 0.991, p
    No preview · Article · Jun 2014 · Arbeitsphysiologie
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