Biomedical subjects

K O Foley

Publications and source records attributed to K O Foley.

3 recordsLinked to original sources

PubMed2000

Effect of cadence, cycling experience, and aerobic power on delta efficiency during cycling.

PURPOSE: To examine the influence of cadence, cycling experience, and aerobic power on delta efficiency during cycling and to determine the significance of delta efficiency as a factor underlying the selection of preferred cadence. METHODS: Delta efficiency (DE) was determined for 11 trained experienced cyclists (C), 10 trained runners (R), and 10 less-trained noncyclists (LT) at 50, 65, 80, 95, and 110 rpm. Preferred cadence (PC) was determined at 100, 150, and 200 W for C and R and at 75, 100, and 150 W for LT. Gas exchange at each power output (PO) was measured on a separate day, and the five cadences were randomly ordered on each occasion. It was hypothesized that: a) cyclists are most efficient at the higher cadences at which they are accustomed to training and racing, i.e., there will be a trend for DE to increase with increases in cadence; b) cyclists and runners will exhibit similar DE across the range of cadences tested; and c) DE of less-trained subjects will be lower than that of cyclists and runners. RESULTS: PCs of C and R were similar and did not change appreciably with PO (100 W:C, 95.6 +/- 10.8; R, 92.0 +/- 8.5: 150 W:C, 94.4 +/- 10.3; R, 92.9 +/- 7.8: 200 W:C, 92.2 +/- 7.2; R, 91.8 +/- 7.9 rpm). The PC of LT was significantly lower and decreased with increases in power output (75 W: 80.0 +/- 15.3; 100 W; 77.5 +/- 15.1; 150 W; 69.1 +/- 11.9 rpm). The first hypothesis was rejected because analysis of the cyclists' data alone revealed no systematic increase in DE as cadence was increased [F(4,40) = 0.272, P = 0.894]. Repeated measures ANOVA on all three groups revealed no group x cadence interaction [F(8,112) = 0.589, P = 0.785]. Again there was no systematic effect of cadence on DE [F(4,112) = 1.058, P = 0.381]. The second and third hypotheses were also rejected since there was no group main effect, i.e., DE of cyclists, runners, and less-trained subjects were not significantly different [F(2,28) = 1.397, P = 0.264]. CONCLUSION: Pedaling cadence did not have a dramatic effect on DE in any group. Muscular efficiency, as measured indirectly by delta efficiency, appears to remain relatively constant at approximately 24%, regardless of cycling experience or fitness level.

Adult↗

PubMed1997

Effects of cardioselective beta blockers on ventilation and gas exchange in patients with heart disease during ramp treadmill testing.

The effects of cardioselective beta blockade on ventilation and gas exchange were investigated in 12 male subjects with coronary artery disease during ramp treadmill testing. Patients were able to maintain much of their functional capacity as measured by oxygen consumption in the beta-blocked condition, and also maintained minute ventilation by increasing respiratory rate despite a decrease in tidal volume.

Adrenergic beta-Antagonists↗

PubMedDate not supplied

Evaluating and understanding performance testing in COPD patients.

PURPOSE: There is increasing interest in the use of performance tests to assess physical function among patients with debilitating diseases. The purpose of this study was to describe the measurement properties of a performance test battery used in the Reconditioning Exercise and Chronic Obstructive Pulmonary Disease Trial and to explore how well-selected physiologic and psychosocial measures explained test performance. METHODS: To assess test-retest reliability of the performance tests, older patients with chronic obstructive pulmonary disease (n = 30) completed, on two different occasions, a 6-minute walk for distance, a timed stair climb, and a timed elevated-arm task. In addition, stepwise regression analyses were conducted on a larger sample (n = 209) to examine how effective conceptually relevant physiologic and psychosocial variables were at explaining variation in task performance. RESULTS: Results showed that all three performance tasks had good test-retest reliability (all coefficients > 0.80) and shared variance in expected directions with VO2peak, forced expiratory volume in 1 second (FEV1), and self-reported disability. Regression analyses suggest that VO2peak, FEV1, self-efficacy, and self-reported disability are important variables to consider in attempts to understand performance-related disability in patients with chronic obstructive pulmonary disease (COPD). CONCLUSIONS: The physical performance test battery appears to be a reliable means of assessing physical functioning in older patients with COPD. Furthermore, findings support the important role that VO2peak plays in task performance and suggest that patients' perceptions should be given careful consideration when attempting to understand physical decline in clinical settings.

Aged↗