Search Results

This experiment examined the effect of a moderate dose of caffeine on quadriceps muscle pain during a bout of high-intensity cycling in low- versus high-caffeine-consuming males. College-age men who were low (≤100 mg/day; n = 12) or high (≥400 mg/day; n = 13) habitual caffeine consumers ingested caffeine (5 mg/kg body weight) or a placebo in a counterbalanced order and 1 hr later completed 30 min of cycle ergometry at 75–77% of peak oxygen consumption. Perceptions of quadriceps muscle pain, as well as oxygen consumption, heart rate, and work rate, were recorded during both bouts of exercise. Caffeine ingestion resulted in a statistically significant and moderate reduction in quadriceps muscle-pain-intensity ratings during the 30-min bout of high-intensity cycle ergometry compared with placebo ingestion in both low (d = −0.42) and high (d = −0.55) caffeine consumers. The results suggest that caffeine ingestion is associated with a moderate hypoalgesic effect during high-intensity cycling in college-age men who are low or high habitual caffeine consumers, but future work should consider better defining and differentiating pain and effort when examining the effects of caffeine during acute exercise.

The purpose of this study was to validate an existing V̇O_2max prediction equation for a graded cycle ergometer test, using adolescents as subjects (14). Healthy, active males (n = 19) and females (n = 19), ages 13–18 years old, pedaled at a rate of 60 rpm until exhaustion, with resistance increasing 15 W every minute. Oxygen uptake, ventilation, and respiratory exchange ratio were measured continuously. A significant correlation was found between predicted and actual V̇O_2max for both male (r = 0.90, p < .001) and female (r = 0.91, p < .001) adolescents. For all subjects combined the correlation was r = 0.96, p < .001 with an SEE = 198 ml · min⁻¹. Mean differences between actual and predicted V̇O_2max values were 1.0 ± 0.7 ml · kg⁻¹ · min⁻¹ and 2.0 ± 0.7 ml · kg⁻¹ · min⁻¹ for the males and females, respectively (2.1% and 5.2% difference). The data indicate these cycle ergometry equations are valid for prediction of V̇O_2max in male and female adolescents.

This study evaluated the feasibility, safety, and findings from a protocol for exercise-bicycle ergometry in subacute-stroke survivors. Of 117 eligible candidates, 14 could not perform the test and 3 discontinued because of cardiac safety criteria. In the 100 completed tests, peak heart rate was 116 ± 19.1 beats/min; peak VO₂ was 11.4 ± 3.7 ml · kg · min⁻¹, peak METs were 3.3 ± 0.91, exercise duration was 5.1 ± 2.84 min., and Borg score was 14 ± 2.6. Among 71 tests, anaerobic threshold was achieved in 3.0 ± 1.7 min with a VO₂ of 8.6 ± 1.7 ml · kg · min⁻¹. After screening, this protocol is feasible and safe in subacute-stroke survivors with mild to moderate deficits. These stroke survivors have severely limited functional exercise capacity. Research and clinical practice in stroke rehabilitation should incorporate more comprehensive evaluation and treatment of endurance limitations.

This study was designed to determine the differing cardiorespiratory responses between maximal treadmill (TM) and cycle (CY) ergometry, and the reliability and variability of these responses in 46 children 7 to 9 years old (23 boys and 23 girls). Two maximal TM and two maximal CY tests were administered, as well as a body composition assessment. The TM resulted in a 9.4%, 11,1%, and 10.2% higher maximal oxygen consumption values (V̇O₂, ml·kg⁻¹·min⁻¹) than the CY in boys, girls, and the total population, respectively. Both the TM and the CY proved to be reliable measures of maximal V̇O₂ (ml·kg⁻¹·min⁻¹) in both boys and girls, with intraclass correlations ranging from R = .63 to .90. Variability was significantly less (p ≤ .05) on the CY (V̇O₂ in L·min⁻¹) than the TM, 4.4% versus 6.2%, respectively.

The authors sought to compare power output at blood lactate threshold, maximal lactate steady state, and pH threshold with the average power output during a simulated 20-km time trial assessed during cycle ergometry. Participants (N = 13) were trained male and female cyclists and triathletes, all permanent residents at moderate altitude (1,525–2,225 m). Testing was performed at 1,525 or 1,860 m altitude. Power outputs were determined during a simulated 20-km time trial (PTT), at blood pH threshold (PpHT), at maximal lactate steady state (PMLSS), and at blood lactate threshold determined by 2 methods: the highest power output that did not result in consecutive and continued increases in blood lactate concentrations from exercising baseline (PLT) and the highest power output that did not result in consecutive and continued increases of ≥1 mmol/L in blood lactate concentrations from exercising baseline (PLT1). PLT, PLT1, and PMLSS were all significantly lower than PpHT (p < .05) and PTT (p < .05). No significant difference was observed between PpHT and PTT (p > .05). Significant correlations were observed between each of the metabolic variables, PLT, PLT1, PMLSS, and PpHT, compared with PTT (p < .05). The authors conclude that, of the 4 metabolic variables, only PpHT offered an accurate reflection of PTT.

Little is known about the responses to graded exercise in athletes with cerebral palsy (CP). This study compared the ventilatory threshold (VT) and peak VO₂ among athletes with CP during treadmill and cycle ergometry exercise. Six (4 men, 2 women) track athletes with CP volunteered to participate in the study. Graded exercise tests on a treadmill and cycle ergometer were performed on separate days to assess VT and peak VO₂. Paired t tests were used to compare the two exercise modes. The VT, expressed as a percentage of peak VO₂, was significantly higher on the cycle ergometer than on the treadmill. The absolute VO₂ at the VT was similar during both testing modes, and peak VO₂ was significantly higher on the treadmill than on the cycle ergometer. Similar to responses seen in able-bodied individuals, the VO₂ at VT was similar during both modes of exercise, while the peak VO₂ was 10% lower on the cycle than on the treadmill. Cycle ergometer peak VO₂ in these athletes was higher than previous reports of individuals with CP for the cycle ergometer.

The purpose of this study was to examine the maximal cardiorespiratory responses of trained adolescent male swimmers (SWM, N = 18), soccer players (SOC, N = 18), and moderately active reference subjects (CON, N = 16) to treadmill running (TRD) and arm ergometry (ARM). Mean values (±SD)for skeletal age were similar among the three groups (12.5± 1.9, 12.7 ± 1.1, and 12.5 ± 1.6 years, for the SWM, SOC, and CON, respectively). Allometric scaling procedures, relating VO₂max and body mass, were used and mass exponents of .80 and .74 were identified for TRD and ARM data, respectively. During TRD testing SOC attained significantly higher VO₂max values when expressed in ml · kg⁻¹ · min⁻¹, or ml · kg^−0.80 · min⁻¹ than the other two groups. However, during ARM testing, the SWM achieved significantly higher VO₂peak values (ml · kg^−0.74 · min⁻¹ and scaled to arm-CSA) than SOC. The ratio of ARM-VAT to TRD-VAT was significantly higher in SWM (50.1± 9%) compared to SOC (41.2±5%), or CON (41.9 ± 6%).