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The purpose of this study was to investigate whether indices of cardiorespiratory fitness are related to quality of life (QOL) in women survivors of breast cancer. Using the European Organization for Research and Treatment of Cancer QLQ-30 questionnaire, we assessed the QOL of 16 participants (age, 50 ± 9 years; body mass, 66.6 ± 9.6 kg). All participants performed incremental cycle ergometer exercise to determine several indices of cardio-respiratory fitness (e.g., peak oxygen uptake [O2peak, in L·min-1, ml·kg-1·min-1]), peak power output (PPO, in W), PPO/ body mass (W·kg-1), peak heart rate (HRpeak, b·min-1), peak ventilation (VEpeak), and O2 and heart rate (HR) at the ventilatory (VT) and respiratory compensation (RCT) thresholds. Relationships between QOL and variables were assessed using Spearman rank-difference correlation tests. A significant inverse relationship (p < 0.05) was found for QOL scores and values for age (years) and body mass (kg) (ρ = -0.53), %HRpeak@VT (ρ = -0.59) and %VEpeak@VT (ρ = -0.61). A significant positive relationship (p < 0.05) was found for QOL and PPO/body mass (ρ =0.59) and HRpeak (ρ = 0.78), O2@RCT (ml·kg-1·min-1)(ρ = 0.51), power output (PO, expressed as either W or W·kg-1) at RCT, and HR at RCT (ρ = 0.54). No other significant relationship was found between QOL and variables obtained from the tests. In conclusion, these findings highlight possible relationships between cardiorespiratory fitness and well-being in survivors of breast cancer. From a practical point of view, our data emphasize the need for this population to engage in programmed cardiorespiratory exercise training, mainly designed to improve VT and RCT. The improvement of both submaximal indices can have a beneficial effect on QOL. [ABSTRACT FROM AUTHOR]

Purpose: To determine the relationship that exists between VO2max and cycling economy/efficiency during intense, submaximal exercise in world-class road professional cyclists. METHODS Each of 11 male cyclists (26+/-1 yr (mean +/- SEM); VO2max: 72.0 +/- 1.8 mL x kg(-1) x min(-1)) performed: 1) a ramp test for O2max determination and 2) a constant-load test of 20-min duration at the power output eliciting 80% of subjects' VO2max during the previous ramp test (mean power output of 385 +/- 7 W). Cycling economy (CE) and gross mechanical efficiency (GE) were calculated during the constant-load tests., Results: CE and GE averaged 85.2 +/- 2.3 W x L(-1) x min(-1) and 24.5 +/- 0.7%, respectively. An inverse, significant correlation was found between 1) VO2max (mL x kg(-0.32) x min(-1)) and both CE (r = -0.71; P = 0.01) and GE (-0.72; P = 0.01), and 2) VO2max (mL x kg(-1) x min(-1)) and both CE (r = -0.65; P = 0.03) and GE (-0.64; P = 0.03)., Conclusions: A high CE/GE seems to compensate for a relatively low VO2max in professional cyclists.

Purpose: To assess the effects of the Rotor (ROT), a new pedaling system that makes each pedal independent from the other so that cranks are no longer fixed at 180 degrees, on endurance cycling performance., Methods: Following a randomized design, eight subjects (noncyclists; age (mean +/- SEM): 22 +/- 1 yr; VO(2max): 51.8 +/- 1.0 mL x kg(-1) x min(-1)) performed two bicycle-ergometer tests on separate days, one with the conventional pedaling system (CON) and the other one with ROT. Starting at 75 W, the power output was increased by 25 W at 3-min intervals until volitional exhaustion. Gas exchange parameters and blood lactate were measured for every 3-min interval., Results: At exercise intensities between 60 and 90% VO(2max), delta efficiency (DE) was significantly higher in ROT than in CON (24.4 +/- 1.9% vs 21.1 +/- 1.1%, respectively)., Conclusions: Although more research is needed, especially with trained riders, the Rotor system might improve delta efficiency during endurance cycling. Other performance determinants VO(2max), maximal power output) do not seem to be changed compared with the conventional system.

Purpose: To analyze the kinetics of oxygen uptake (VO(2)) in professional road cyclists during a ramp cycle ergometer test and to compare the results with those derived from well-trained amateur cyclists., Methods: Twelve professional cyclists (P group; 25 +/- 1 yr; maximal power output (W(max)), 508.3 +/- 9.3 watts) and 10 amateur cyclists (A group; 22 +/- 1 y; W(max), 429.9 +/- 8.6 watts) performed a ramp test until exhaustion (power output increases of 25 watts x min(-1)). The regression lines of the VO(2):power output (W) relationship were calculated for the following three phases: phase I (below the lactate threshold (LT)), phase II (between LT and the respiratory compensation point (RCP)), and phase III (above RCP)., Results: In group P, the mean slope (Delta VO(2):Delta W) of the VO(2):W relationship decreased significantly (P < 0.01) across the three phases (9.9 +/- 0.1, 8.9 +/- 0.2, and 3.8 +/- 0.6 mL O(2) x watts(-1) x min(-1) for phases I, II, and III, respectively). No significant differences (P > 0.05) were found between phases I and II (P > 0.05) in group A, whereas Delta VO(2):Delta W significantly increased in phase III (P < 0.01), compared with phase II (10.2 +/- 0.3, 9.2 +/- 0.4, and 10.1 +/- 1.1 mL O(2) x watts(-1) x min(-1) in phases I, II, and III, respectively). The mean value of Delta VO(2):Delta W for phase III was significantly lower in group P than in group A (P < 0.01)., Conclusion: Contrary to the case in amateur riders, the rise in VO(2) in professional cyclists is attenuated at moderate to high workloads. This is possibly an adaptation to the higher demands of their training/competition schedule.

Purpose: To determine the relationship between the additional, nonlinear increase in oxygen uptake (Delta VO(2)) that occurs at high power outputs during a ramp cycle ergometer test, on one hand; and possible explanatory mechanisms of the phenomenon, such as cardiorespiratory work, blood lactate, fitness level, or muscle fiber distribution, on the other., Methods: Ten healthy, sedentary young adults (age (mean +/- SEM), 22 +/- 1 yr) were chosen as subjects. A muscle biopsy specimen was taken from the vastus lateralis of the right leg to determine fiber type distribution by immunohistochemical identification of myosin heavy chain (MHC) isoforms. During the ramp tests (power output increases of 5 W every 15-s interval), the ventilatory threshold (VT) and lactate threshold (LT) were measured. We defined Delta VO(2) as the difference between "true" VO(2) values observed at the maximal power output (VO(2)obs) and those expected (VO(2)exp) from the previous linear VO2:power output relationship below the VT., Results: A nonlinear increase was observed in VO2 (Delta VO(2) = 239 +/- 79 mL x min(-1), P < 0.05 for VO(2)obs vs VO(2)exp), which was significantly correlated with the percentage of type IIX fibers (r = 0.80, P < 0.05). No other correlations were found between Delta VO(2) and possible explanatory mechanisms., Conclusion: A greater percentage of type IIX fibers is associated with a higher excess VO(2) at high power outputs (above VT).