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 &amp Science in Sports &amp Exercise (Impact Factor: 4.46). 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.

5 Bookmarks
 · 
860 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Within individuals, critical power appears sensitive to manipulations in O2 delivery. We asked whether interindividual differences in forearm O2 delivery might account for a majority of the interindividual differences in forearm critical force impulse (critical impulse), the force analog of critical power. Ten healthy men (24.6 ± 7.10 years) completed a maximal effort rhythmic handgrip exercise test (1 sec contraction-2 sec relaxation) for 10 min. The average of contraction impulses over the last 30 sec quantified critical impulse. Forearm brachial artery blood flow (FBF; echo and Doppler ultrasound) and mean arterial pressure (MAP; finger photoplethysmography) were measured continuously. O2 delivery (FBF arterial oxygen content (venous blood [hemoglobin] and oxygen saturation from pulse oximetry)) and forearm vascular conductance (FVC; FBF·MAP−1) were calculated. There was a wide range in O2 delivery (59.98–121.15 O2 mL·min−1) and critical impulse (381.5–584.8 N) across subjects. During maximal effort exercise, O2 delivery increased rapidly, plateauing well before the declining forearm impulse and explained most of the interindividual differences in critical impulse (r2 = 0.85, P < 0.01). Both vasodilation (r2 = 0.64, P < 0.001) and the exercise pressor response (r2 = 0.33, P < 0.001) independently contributed to interindividual differences in FBF. In conclusion, interindividual differences in forearm O2 delivery account for most of the interindividual variation in critical impulse. Furthermore, individual differences in pressor response play an important role in determining differences in O2 delivery in addition to vasodilation. The mechanistic origins of this vasodilatory and pressor response heterogeneity across individuals remain to be determined.
    11/2014; 2(11). DOI:10.14814/phy2.12203
  • [Show abstract] [Hide abstract]
    ABSTRACT: THE STEADY-STATE MODEL OF BIOENERGETICS FAILS TO ACCURATELY DESCRIBE THE METABOLISM FOR HIGH-INTENSITY POWER. THIS ARTICLE REEXAMINES THE ROLE OF PHOSPHOCREATINE, LACTATE PRODUCTION, AND THE IMPORTANCE OF AEROBIC METABOLISM DURING SHORT-TERM HIGH-INTENSITY POWER PERFORMANCE. METABOLIC AND MECHANICAL TESTS OF HIGH-INTENSITY POWER HAVE EVOLVED IN THE PAST 40 YEARS. THE AUTHORS COMPARED THE MAXIMAL ACCUMULATED OXYGEN-DEFICIT MODEL VERSUS THE CRITICAL POWER MODEL AND SUMMARIZED THE RECENTLY DEVELOPED 3-MINUTE ALL-OUT EXERCISE TEST (3 MT). THE 3 MT OFFERS THE STRENGTH AND CONDITIONING PROFESSIONAL A SIMPLE METHOD OF ESTIMATING AN ATHLETE'S TOLERANCE TO HIGH-INTENSITY POWER EXERCISE.
    Strength and conditioning journal 01/2013; 35(2):11-16. DOI:10.1519/SSC.0b013e31828a9520 · 0.77 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: It is not known if the respiratory compensation point (RCP) is a distinct work rate (Watts (W)) or metabolic rate [Formula: see text] and if the RCP is mechanistically related to critical power (CP). To examine these relationships, 10 collegiate men athletes performed cycling incremental and constant-power tests at 60 and 100rpm to determine RCP and CP. RCP work rate was significantly (p≤0.05) lower for 100 than 60rpm (197±24W vs. 222±24W), while RCP [Formula: see text] was not significantly different (3.00±0.33lmin(-1) vs. 3.12±0.41lmin(-1)). CP at 60rpm (214±51W; [Formula: see text] : 3.01±0.69lmin(-1)) and 100rpm (196±46W; [Formula: see text] : 2.95±0.54lmin(-1)) were not significantly different from RCP. However, RCP and CP were not significantly correlated. These findings demonstrate that RCP represents a distinct metabolic rate, which can be achieved at different power outputs, but that RCP and CP are not equivalent parameters and should not, therefore, be used synonymously. Copyright © 2014. Published by Elsevier B.V.
    Respiratory Physiology & Neurobiology 12/2014; 208. DOI:10.1016/j.resp.2014.12.008 · 1.97 Impact Factor

Full-text (2 Sources)

Download
950 Downloads
Available from
May 31, 2014