The present study aimed to investigate the influence of timing of preexercise carbohydrate feeding (Part A) and carbohydrate concentration (Part B) on short-duration high-intensity exercise capacity. In Part A, 17 males, and in Part B 10 males, performed a peak power output (PPO) test, two familiarization trials at 90% of PPO, and 4 (for Part A) or 3 (for Part B) experimental trials involving exercise capacity tests at 90% PPO. In Part A, the 4 trials were conducted following ingestion of a 6.4% carbohydrate/electrolyte sports drink ingested 30 (C30) or 120 (C120) minutes before exercise, or a flavor-matched placebo administered either 30 (P30) or 120 (P120) minutes before exercise. In Part B, the 3 trials were performed 30 min after ingestion of 0%, 2% or 12% carbohydrate solutions. All trials were performed in a double-blind cross-over design following and overnight fast. Dietary intake and activity in the 2 days before trials was recorded and replicated on each visit. Glucose, lactate, heart rate, and mood/arousal were recorded at intervals during the trials. In Part A, C30 produced the greatest exercise capacity (mean ± SD; 9.0 ± 1.9 min, p < .01) compared with all other trials (7.7 ± 1.5 min P30, 8.0 ± 1.7 min P120, 7.9 ± 1.9 min C120). In Part B, exercise capacity (min) following ingestion of the 2% solution (9.2 ± 2.1) compared with 0% (8.2 ± 0.7) and 12% (8.0 ± 1.3) solutions approached significance (p = .09). This study provides new evidence to suggest that timing of carbohydrate intake is important in short duration high-intensity exercise tasks, but a concentration effect requires further exploration.
Stuart D.R. Galloway, Matthew J.E. Lott and Lindsay C. Toulouse
Peter M. Christensen and Jens Bangsbo
To evaluate the influence of warm-up exercise intensity and subsequent recovery on intense endurance performance, selected blood variables, and the oxygen-uptake (VO2) response.
Twelve highly trained male cyclists (VO2max 72.4 ± 8.0 mL · min−1 · kg−1, incremental-test peak power output (iPPO) 432 ± 31 W; mean ± SD) performed 3 warm-up strategies lasting 20 min before a 4-min maximal-performance test (PT). Strategies consisted of moderate-intensity exercise (50%iPPO) followed by 6 min of recovery (MOD6) or progressive high-intensity exercise (10–100%iPPO and 2 × 20-s sprints) followed by recovery for 6 min (HI6) or 20 min (HI20).
Before PT venous pH was lower (P < .001) in HI6 (7.27 ± 0.05) than in HI20 (7.34 ± 0.04) and MOD6 (7.35 ± 0.03). At the same time, differences (P < .001) existed for venous lactate in HI6 (8.2 ± 2.0 mmol/L), HI20 (5.1 ± 1.7 mmol/L), and MOD6 (1.4 ± 0.4 mmol/L), as well as for venous bicarbonate in HI6 (19.3 ± 2.6 mmol/L), HI20 (22.6 ± 2.3 mmol/L), and MOD6 (26.0 ± 1.4 mmol/L). Mean power in PT in HI6 (402 ± 38 W) tended to be lower (P = .11) than in HI20 (409 ± 34 W) and was lower (P = .007) than in MOD6 (416 ± 32 W). Total VO2 (15–120 s in PT) was higher in HI6 (8.18 ± 0.86 L) than in HI20 (7.85 ± 0.82 L, P = .008) and MOD6 (7.90 ± 0.74 L, P = .012).
Warm-up exercise including race-pace and sprint intervals combined with short recovery can reduce subsequent performance in a 4-min maximal test in highly trained cyclists. Thus, a reduced time at high exercise intensity, a reduced intensity in the warm-up, or an extension of the recovery period after an intense warm-up is advocated.
Twan ten Haaf, Selma van Staveren, Danilo Iannetta, Bart Roelands, Romain Meeusen, Maria F. Piacentini, Carl Foster, Leo Koenderman, Hein A.M. Daanen and Jos J. de Koning
increased 40 W for men and 30 W for women every 3 minutes. Subjects cycled at a freely chosen cadence. The test was stopped when subjects were unable to maintain the cadence above 60 rpm, despite strong verbal encouragement. Peak power output was defined as the average power output over the last 3 minutes
Emma L. Sweeney, Daniel J. Peart, Irene Kyza, Thomas Harkes, Jason G. Ellis and Ian H. Walshe
< .05). Exercise Peak power output during each of the 30-s sprints is outlined in Table 2 . Peak power output did not differ between conditions ( p = .644), but a difference was observed over time ( p < .001), with peak power output significantly higher in the first sprint compared with the third
Seiichiro Takei, Kuniaki Hirayama and Junichi Okada
maximized at 1RM. However, previous studies have reported that submaximal loads are optimal for peak power output during HPC. 6 – 10 There are 2 possible explanations for these results. First, the movement might not be executed correctly at heavy loads. Because it is not easy to perform ballistic exercises
Yasuki Sekiguchi, Erica M. Filep, Courteney L. Benjamin, Douglas J. Casa and Lindsay J. DiStefano
method in 39°C and 56% RH for 8 d. Adaptations in plasma volume, HR, T int , T skin , and sweat loss were measured by heat stress test prior to and following heat acclimation. HST was consisted of 60 min at 35% of peak power output in 39°C and 53% RH. EUH (1.4% BML) and DEH (2.4% BML) groups performed
Bruno Ferreira Viana, Flávio Oliveira Pires, Allan Inoue and Tony Meireles Santos
Cross-country mountain biking (XCO) is a high-intensity endurance sporting event 1 , 2 in which athletes are required to generate power-output values ranging from ∼50 to 400 W. In fact, mean power output has been shown to be around 208 W, while peak power output has been shown to be as high as
Adam Beard, John Ashby, Ryan Chambers, Franck Brocherie and Grégoire P. Millet
= .12; η p 2 = .08 ) throughout the protocol. Figure 1 —PPO in successive sprints during the repeated-cycling sprint test before and after specific RSH or RSN. Values are mean (SD). Significant differences from pretest, * P < .05, ** P < .01, *** P < .001. PPO indicates peak power output; RSH
Sandro Venier, Jozo Grgic and Pavle Mikulic
Metikos et al 22 who previously validated this test. During these “all-out” strokes, peak power output was the highest external power output, as displayed on the Concept 2 performance monitor. The CV for this outcome amounted to 2.5%. Side Effects Immediately after the completion of the testing sessions
Christopher J. Keating, Juan Á. Párraga Montilla, Pedro Á. Latorre Román and Rafael Moreno del Castillo
; Iellamo et al., 2014 ), one study utilized VO 2 peak ( Mitranun et al., 2014 ), one study utilized peak power output ( Currie et al., 2013 ), one utilized rate of perceived exertion ( Cassidy et al., 2016 ), one study utilized VO 2 reserve ( Terada et al., 2013 ), and one study utilized estimated safe