Search Results

The Effect of Seat Back Angle on Responses During Recumbent Cycling
The purpose of this study was to evaluate metabolic, cardiorespiratory, and perceptual responses during recumbent cycle ergometry performed at various seat back angles and different work rates. Healthy college-aged men performed steady-state exercise at two work rates, 100 watts (n=46) and 150 watts (n=26), using five back seat angles, 90, 105, 120, 135, and 150 degrees. The results of this study suggest that recumbent seat back angles of 135 to 150 degrees are associated with lower metabolic and cardiorespiratory stress during rest and submaximal exercise than more upright positions. The reduced stress at these angles is accompanied by lower perceptions of exertion and improved seating comfort. The failure of the base-line correction for resting V0 2 to remove the effect of seat back angle implies that the reduced physiological stress associated with these positions is due to reasons other than attenuated resting metabolic costs. It is concluded that the selection of recumbent seat back angles between 135 and 150 degrees can result in improved efficiency, reduced physiological stress, diminished perceptions of exertion, and increased seating comfort.
The Effect of Mode and Intensity on Vo2 Kinetics in the Severe Intensity Domain
The purpose of this study was to evaluate the effect of mode and intensity on VO2 kinetics in the severe intensity domain. Seventeen participants completed 3-7 tests each on a cycle ergometer and treadmill. For each test, Tfatigue, VO2max, Tmean response, VO2GAIN, TVO2max and T@VO2max were determined. Linear regression techniques were used to describe the relationship between TVO2max and Tfatigue . VO2max values were higher in running. The VO2 response profile was faster for running than cycling and faster at higher intensities. The faster VO2 response in running may be associated with larger active muscle mass or differences in muscle activation patterns. The faster response at higher intensities may suggest that VO2 response is driven by O2 demand.
Cardiorespiratory Responses to Graded Levels of Lower-body Positive Pressure During Dynamic Exercise in Man
Cardiorespiratory responses to incremental dynamic exercise were assessed across four different levels of lower-body positive pressure (LBPP) and, as a separate study, during constant load (i.e constant work rate) exercise below and above each subject's ventilatory threshold (VT), both with and without 45 torr of LBPP.
Temporal Specificity in Exercise Training
The primary purpose of this study was to investigate the effect of training at a particular time of day on anaerobic capacity in the morning and in the afternoon.
Morning and Afternoon Response to Exercise Using Two Test Protocols
The purpose was to investigate time of day on responses to two types of exhaustive cycle ergometer tests. Sixteen males performed six exercise tests: three - constant power protocol and three - incremental protocol. The first test was a learning trial; the other tests were performed one in the morning and one in the afternoon. ANOVA revealed that O2 deficit and lactate were higher in the afternoon than the morning. Regardless of test type, time to exhaustion tended to be higher in the afternoon. VO2max was unaffected by the time of day and test type. These results confirmprevious reports of a time of day effect on anaerobic capacity, and support the contention that V02max is stable about a day.
Effects of Endurance Intensity and Rest Interval on Subsequent Strength Performance
The purpose of this study was to examine the acute effects of cycling exercise at different intensities and rest intervals on strength performance. Ten males, engaged in concurrent training for at least one month prior to testing, comprised the subject group for this study. Results show only leg press torque and leg press work to be decreased after cardiorespiratory exercise of moderate intensity. Leg extension average power, chest press torque, chest press power, and chest press work after cycling were not decreased from pre-exercise values. No significant effects were found for exercise intensity, testing times, or intensity by testing times. These results indicate that lower body strength is decreased by cycling and that one hour is not sufficient to restore leg strength.
Critical Power as a Predictor of Performance in a Bicycle Time Trial
Certain measures of aerobic power have been shown to have a high relationship with endurance performance. Critical power (CP) has also been shown to be well correlated to endurance performance, but few studies have evaluated its use in a competitive scenario. In this study, cardiorespiratory-metabolic measures were evaluated in 13 highly trained cyclists to determine their relationship to performance in a 17 km time trial. Critical power, determined from the nonlinear power-time model, was also evaluated to determine its relationship to performance in a 17 km time trial. Results indicate that the traditional indicators of V02max and ventilatory anaerobic threshold were well correlated to TT performance (r=-0.86, r=-0.79, respectively). The principal finding from this study was that performance in a bicycle time trial is related to CP at least as well as to cardiorespirator-ymetabolic measures. In fact, the results fromthis study suggest that the relationship between performance and CP is stronger (r=-0.89). Use of the critical power concept is attractive because testing requires only a cycle ergometer and a stopwatch to estimate a parameter of aerobic fitness.
Back to Top of Screen