highest 30-second mean V ˙ O 2 value achieved during the test. Incremental peak power output (PPO) was also determined. Over the following 7 days participants returned to the lab for familiarization purposes to complete two 4-km laboratory-based time trials in a temperate (20°C, 60% RH) environment
Joseph A. McQuillan, Julia R. Casadio, Deborah K. Dulson, Paul B. Laursen and Andrew E. Kilding
Myriam Paquette, François Bieuzen and François Billaut
maximal incremental test on a canoe or kayak ergometer at the end of their competitive season to examine the relation between peak power output (PPO) and various physiological variables (cardiac output, VO 2 max, and muscle oxygenation). A subset of 21 participants (8 MK, 4 MC, 4 WK, and 5 WC) also
Pablo Jodra, Raúl Domínguez, Antonio J. Sánchez-Oliver, Pablo Veiga-Herreros and Stephen J. Bailey
placebo condition. This improvement in variables related to acceleration and peak power output after BJ supplementation might be expected to translate into enhanced acceleration, rate of force development, and peak force development. Subsequently, these enhancements might be expected to improved
Avish P. Sharma, David J. Bentley, Gaizka Mejuto and Naroa Etxebarria
-three well-trained male cyclists volunteered to participate in this study, and they were categorized into 2 groups: 10 national- (Australian National Road Series) and 13 club-level cyclists (peak power output [PPO] 359  W or 5.4 [0.5] W·kg −1 and 362  W or 4.6 [0.4] W·kg −1 , VO 2 peak 65.6 [3
Marco J. Konings, Jordan Parkinson, Inge Zijdewind and Florentina J. Hettinga
participants completed in a randomized order 1 of the 2 different experimental 4-km TT conditions (see Procedures). No verbal coaching or motivation was given to the subjects during any of the TTs. Before each TT condition, subjects performed a 5-minute warm-up at an intensity of 30% peak power output (PPO
Sally P. Waterworth, Connor C. Spencer, Aaron L. Porter and James P. Morton
impaired during the morning training session. Indeed, we recently observed that stepwise reductions in preexercise muscle glycogen concentration ∼100 mmol/kg of dry weight (as achieved by the sleep-low model) impaired morning exercise capacity at 80% peak power output (PPO) by ∼20–50% ( Hearris et
Gethin H. Evans, Phillip Watson, Susan M. Shirreffs and Ronald J. Maughan
Previous investigations have suggested that exercise at intensities greater than 70% maximal oxygen uptake (VO2max) reduces gastric emptying rate during exercise, but little is known about the effect of exercise intensity on gastric emptying in the postexercise period. To examine this, 8 healthy participants completed 3 experimental trials that included 30 min of rest (R), low-intensity (L; 33% of peak power output) exercise, or high-intensity (H; 10 × 1 min at peak power output followed by 2 min rest) exercise. Thirty minutes after completion of exercise, participants ingested 595 ml of a 5% glucose solution, and gastric emptying rate was assessed via the double-sampling gastric aspiration method for 60 min. No differences (p > .05) were observed in emptying characteristics for total stomach volume or test meal volume between the trials, and the quantity of glucose delivered to the intestine did not differ between trials (p > .05). Half-emptying times did not differ (p = .902) between trials and amounted to 22 ± 9, 22 ± 9, and 22 ± 7 min (M ± SD) during the R, L, and H trials, respectively. These results suggest that exercise has little effect on postexercise gastric emptying rate of a glucose solution.
Veronique Labelle, Laurent Bosquet, Said Mekary, Thien Tuong Minh Vu, Mark Smilovitch and Louis Bherer
The purpose of this study was to assess the effects of exercise intensity, age, and fitness levels on executive and nonexecutive cognitive tasks during exercise. Participants completed a computerized modified-Stroop task (including denomination, inhibition, and switching conditions) while pedaling on a cycle ergometer at 40%, 60%, and 80% of peak power output (PPO). We showed that a bout of moderate-intensity (60% PPO) to high-intensity (80% PPO) exercise was associated with deleterious performance in the executive component of the computerized modified-Stroop task (i.e., switching condition), especially in lower-fit individuals (p < .01). Age did not have an effect on the relationship between acute cardiovascular exercise and cognition. Acute exercise can momentarily impair executive control equivalently in younger and older adults, but individual’s fitness level moderates this relation.
Carl D. Paton
Aerobic economy is an important factor that affects the performance of competitive cyclists. It has been suggested that placing the foot more anteriorly on the bicycle pedals may improve economy over the traditional foot position by improving pedaling efficiency. The current study examines the effects of changing the anterior-posterior pedal foot position on the physiology and performance of well-trained cyclists.
In a crossover study, 10 competitive cyclists completed two maximal incremental and two submaximal tests in either their preferred (control) or a forward (arch) foot position. Maximum oxygen consumption and peak power output were determined from the incremental tests for both foot positions. On two further occasions, cyclists also completed a two-part 60-min submaximal test that required them to maintain a constant power output (equivalent to 60% of their incremental peak power) for 30 min, during which respiratory and blood lactate samples were taken at predetermined intervals. Thereafter, subjects completed a 30-min self-paced maximal effort time trial.
Relative to the control, the mean changes (±90% confidence limits) in the arch condition were as follows: maximum oxygen consumption, -0.5% (±2.0%); incremental peak power output, -0.8% (±1.3%); steady-state oxygen consumption at 60%, -2.4% (±1.1%); steady-state heart rate 60%, 0.4% (±1.7%); lactate concentration 60%, 8.7% (±14.4%); and mean time trial power, -1.5% (±2.9%).
We conclude that there was no substantial physiological or performance advantage in this group using an arch-cleat shoe position in comparison with a cyclist’s normal preferred condition.
Iker Leoz-Abaurrea, Mikel Izquierdo, Miriam Gonzalez-Izal and Roberto Aguado-Jiménez
The efficacy of the use of an upper body compression garment (UBCG) as an ergogenic aid to reduce thermoregulatory strain in older adults remains unknown. The aim of this study was to evaluate the effects of UBCG on thermoregulatory, cardiorespiratory, and perceptual responses during cycling in a temperate environment (~25 °C, 66% rh) in trained older adults. Twelve cyclists aged 66 ± 2 years performed an intermittent 1-hr cycling trial at 50% of the peak power output followed by 10 min of passive recovery. Participants were provided with either commercially available UBCG or a control garment in a randomized order. UBCG increased thermoregulatory strain during exercise, as indicated by a significantly higher core temperature (38.1 ± 0.3 °C vs. 37.9 ± 0.3 °C; p = .04), body temperature (36.9 ± 0.2 °C vs. 36.7 ± 0.2 °C; p = .01), and thermal sensation (8.0 ± 0.4 vs. 7.5 ± 1.0; p = .02). These results suggest that the use of UBCG in trained older adults does not reduce the thermoregulatory strain during moderate exercise.