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The purposes of this study were to compare the patterns of the work rate (WR)-Vo2 and WR-heart rate (HR) relationships in incremental cycling, to ascertain the occurrence of a Vo2 deflection (Vo2def) coinciding with the HR deflection point (HRdef ), and to determine whether the Vo2def, if present, coincides with the ventilatory anaerobic threshold (VT). Twenty-four professional cyclists performed a maximal incremental test on a wind-load cycle ergometer. Work rate, HR, Vo2, and Vco2 were recorded. The WR-Vo2 relationships obtained were linear up to submaximal WR and curvilinear thereafter and thus described a Vo2def. The WR and Vo2 at Vo2def were mathematically determined for all subjects. The ratio of DeltaWR.DeltaVo2 up to Vo2def was significantly lower than that above Vo2def (90 +/- 11 W.L.min versus 133 +/- 35 W.L.min, p < 0.0001). The WR-HR relationships obtained were linear up to submaximal WR and curvilinear thereafter. The WR and HR at HRdef were mathematically determined for all subjects. The WR values at Vo2def and at HRdef (329 +/- 32 W and 326 +/- 34 W) were significantly correlated (R = 0.96, p < 0.0001) and in good concordance (limits of agreement from -4.7% to 3.2%, Bland-Altman analysis). The Vo2 at VT was then determined for all subjects. The Vo2 values at Vo2def and at VT were significantly correlated (R = 0.99, p < 0.0001) and in strong concordance (limits of agreement from -1.9% to 1.0%, Bland-Altman analysis). In conclusion, a Vo2def coinciding with HRdef and VT was shown. This confirms that the determination of the WR-HR relationship and of HRdef is a practical and noninvasive means of identifying anaerobic threshold. [ABSTRACT FROM AUTHOR]

Normal standards for peak oxygen consumption (VO 2 peak) are controversial because they tend to be population and protocol specific. This study was undertaken to examine the association between percentage of age-predicted VO 2 peak and all-cause hospital readmission in cardiac outpatients who were referred to an exercise-based secondary prevention program. Hospital readmission was assessed in 1283 male patients with coronary heart disease (CHD) three years after enrolment, and related to the age-predicted VO 2 peak derived from the Fitness Registry and the Importance of Exercise: A National Data Base equation (FRIEND %PRED). VO 2 peak was estimated using a moderate perceptually regulated 1-km treadmill-walking test. Readmission was also assessed during the fourth-to-sixth years as function of improvement in FRIEND %PRED in 845 patients who were re-evaluated 3 years after baseline. During the 3-years after baseline, readmission rate was lower across increasing tertiles of FRIEND %PRED. Compared to the lowest tertile, the adjusted hazard ratios (HRs) for the second and third tertile were 0.98 (95% CI 0.76–1.27, p = 0.90) and 0.71 (0.53–0.95, p = 0.002). The rate of readmission from the fourth-to-sixth years after baseline was lower across tertiles of improved FRIEND %PRED , with adjusted HRs 0.78 (0.60–1.03, p = 0.08) and 0.58 (0.42–0.75, p < 0.0001) for the intermediate and high tertiles vs the lowest tertile. After adjustment for confounders, every 1 unit % increase in FRIEND %PRED was associated with a 3% reduction in risk of readmission (HR 0.97, 0.95–0.98, p < 0.0001). Age-predicted VO 2 peak estimated by a moderate treadmill-walk predicts hospital readmission in outpatients with CHD undergoing secondary prevention. [ABSTRACT FROM AUTHOR]