The objective of this study was to propose an alternative method (MAOD(ALT)) to estimate the maximal accumulated oxygen deficit (MAOD) using only one supramaximal exhaustive test. Nine participants performed the following tests: (a) a maximal incremental exercise test, (b) six submaximal constant workload tests, and (c) a supramaximal constant workload test. Traditional MAOD was determined by calculating the difference between predicted O(2) demand and accumulated O(2) uptake during the supramaximal test. MAOD(ALT) was established by summing the fast component of excess post-exercise oxygen consumption and the O(2) equivalent for energy provided by blood lactate accumulation, both of which were measured during the supramaximal test. There was no significant difference between MAOD (2.82+/-0.45 L) and MAOD(ALT) (2.77+/-0.37 L) (P=0.60). The correlation between MAOD and MAOD(ALT) was also high (r=0.78; P=0.014). These data indicate that the MAOD(ALT) can be used to estimate the MAOD.

The present study cross-sectionally investigated the influence of training status, route difficulty and upper body aerobic and anaerobic performance of climbers on the energetics of indoor rock climbing. Six elite climbers (EC) and seven recreational climbers (RC) were submitted to the following laboratory tests: (a) anthropometry, (b) upper body aerobic power, and (c) upper body Wingate test. On another occasion, EC subjects climbed an easy, a moderate, and a difficult route, whereas RC subjects climbed only the easy route. The fractions of the aerobic (W(AER)), anaerobic alactic (W(PCR)) and anaerobic lactic (W[La(-)]) systems were calculated based on oxygen uptake, the fast component of excess post-exercise oxygen uptake, and changes in net blood lactate, respectively. On the easy route, the metabolic cost was significantly lower in EC [40.3 (6.5) kJ] than in RC [60.1 (8.8) kJ] (P < 0.05). The respective contributions of the W (AER), W (PCR), and W[La(-)] systems in EC were: easy route = 41.5 (8.1), 41.1 (11.4) and 17.4% (5.4), moderate route = 45.8 (8.4), 34.6 (7.1) and 21.9% (6.3), and difficult route = 41.9 (7.4), 35.8 (6.7) and 22.3% (7.2). The contributions of the W (AER), W (PCR), and W[La(-)] systems in RC subjects climbing an easy route were 39.7 (5.0), 34.0 (5.8), and 26.3% (3.8), respectively. These results indicate that the main energy systems required during indoor rock climbing are the aerobic and anaerobic alactic systems. In addition, climbing economy seems to be more important for the performance of these athletes than improved energy metabolism.

The aim of this study was to investigate the effects of caffeine on reaction time during a specific taekwondo task and athletic performance during a simulated taekwondo contest. Ten taekwondo athletes ingested either 5 mg·kg−1 body mass caffeine or placebo and performed two combats (spaced apart by 20 min). The reaction-time test (five kicks “Bandal Tchagui”) was performed immediately prior to the first combat and immediately after the first and second combats. Caffeine improved reaction time (from 0.42 ± 0.05 to 0.37 ± 0.07 s) only prior to the first combat (P = 0.004). During the first combat, break times during the first two rounds were shorter in caffeine ingestion, followed by higher plasma lactate concentrations compared with placebo (P = 0.029 and 0.014, respectively). During the second combat, skipping-time was reduced, and relative attack times and attack/skipping ratio was increased following ingestion of caffeine during the first two rounds (all P < 0.05). Caffeine resulted in no change in combat intensity parameters between the first and second combat (all P > 0.05), but combat intensity was decreased following placebo (all P < 0.05). In conclusion, caffeine reduced reaction time in non-fatigued conditions and delayed fatigue during successive taekwondo combats.

The aim of this study was to analyze the changes on repeated-sprint ability (RSA) performance after heavy load exercise in elite handball players. Twelve subjects were submitted to the following experimental sessions: (a) 1-repetition maximum (1RM) test on the half squat exercise, (b) RSA test (control condition), and (c) RSA with a conditioning activity on the same exercise as 1RM test (experimental condition). The conditioning activity comprised 1 set of 5 × 50% 1RM, 1 set of 3 × 70% 1RM, and 5 sets of 1 × 90% 1RM. A significant improvement in the best sprint time (RSAbest) and mean sprint time (RSAmean) was observed with the conditioning activity (RSAbest = 5.74 ± 0.16 seconds; RSAmean = 5.99 ± 0.19 seconds) when compared with the situation without the conditioning activity (RSAbest = 5.82 ± 0.15 seconds; RSAmean = 6.06 ± 0.18 seconds; p < 0.01) with a moderate (Cohen's d = -0.54) and small effect (Cohen's d = -0.41) to RSAbest and RSAmean, respectively. Therefore, the findings of this study demonstrated that prior heavy load exercise can be used to improve the RSA performance, however, with a small to moderate magnitude of change.

The purpose of the present study was to investigate the effects of caffeine ingestion on pacing strategy and energy expenditure during a 4000-m cycling time-trial (TT). Eight recreationally-trained male cyclists volunteered and performed a maximal incremental test and a familiarization test on their first and second visits, respectively. On the third and fourth visits, the participants performed a 4000-m cycling TT after ingesting capsules containing either caffeine (5 mg.kg−1 of body weight, CAF) or cellulose (PLA). The tests were applied in a double-blind, randomized, repeated-measures, cross-over design. When compared to PLA, CAF ingestion increased mean power output [219.1±18.6 vs. 232.8±21.4 W; effect size (ES)  = 0.60 (95% CI = 0.05 to 1.16), p = 0.034] and reduced the total time [419±13 vs. 409±12 s; ES = −0.71 (95% CI = −0.09 to −1.13), p = 0.026]. Furthermore, anaerobic contribution during the 2200-, 2400-, and 2600-m intervals was significantly greater in CAF than in PLA (p<0.05). However, the mean anaerobic [64.9±20.1 vs. 57.3±17.5 W] and aerobic [167.9±4.3 vs. 161.8±11.2 W] contributions were similar between conditions (p>0.05). Similarly, there were no significant differences between CAF and PLA for anaerobic work (26363±7361 vs. 23888±6795 J), aerobic work (68709±2118 vs. 67739±3912 J), or total work (95245±8593 vs. 91789±7709 J), respectively. There was no difference for integrated electromyography, blood lactate concentration, heart rate, and ratings of perceived exertion between the conditions. These results suggest that caffeine increases the anaerobic contribution in the middle of the time trial, resulting in enhanced overall performance.

The relationship between carbohydrate (CHO) availability and exercise performance has been thoroughly discussed. CHO improves performance in both prolonged, low-intensity and short, high-intensity exercises. Most studies have focused on the effects of CHO supplementation on the performance of constant-load, time-to-exhaustion exercises. Nevertheless, in the last 20 years, there has been a consistent increase in research on the effects of different forms of CHO supplementation (e.g., diet manipulation, CHO supplementation before or during exercise) on performance during closed-loop exercises, such as cycling time trials (TTs). A TT is a highly reproducible exercise and reflects a more realistic scenario of competition compared with the time-to-exhaustion test. CHO manipulation has been performed in various time periods, such as days before, minutes before, during a TT or in a matched manner (e.g. before and during a TT). The purpose of this review is to address the possible effects of these different forms of CHO manipulation on the performance during a cycling TT. Previous data suggest that when a high-CHO diet (~70% of CHO) is consumed before a TT (24-72 h before), the mean power output increases and reduces the TT time. When participants are supplemented with CHO (from 45 to 400 g) prior to a TT (from 2 min to 6 h before the TT), mean power output and time seem to improve due to an increase in CHO oxidation. Similarly, this performance also seems to increase when participants ingest CHO during a TT because such consumption maintains plasma glucose levels. A CHO mouth rinse also improves performance by activating several brain areas related to reward and motor control through CHO receptors in the oral cavity. However, some studies reported controversial results concerning the benefits of CHO on TT performance. Methodological issues such as time of supplementation, quantity, concentration and type of CHO ingested, as well as the TT duration and intensity, should be considered in future studies because small variations in any of these factors may have beneficial or adverse effects on TT performance.

Preexercise acidosis, but not alkalosis, affects anaerobic metabolism and PO during a 4-km cycling TT.

This study determined which peripheral variables would better predict the rating of perceived exertion (RPE) and time to exhaustion (TE) during exercise at different intensities. Ten men performed exercises at first lactate threshold (LT1), second lactate threshold (LT2), 50% of the distance from LT1 to LT2 (TT(50%) ), and 25% of the distance from LT2 to maximal power output (TW(25%) ). Lactate, catecholamines, potassium, pH, glucose, V(·)O₂, VE, HR, respiratory rate (RR) and RPE were measured and plotted against the exercise duration for the slope calculation. Glucose, dopamine, and noradrenaline predicted RPE in TT(50%) (88%), LT2 (64%), and TW(25%) (77%), but no variable predicted RPE in LT1. RPE (55%), RPE+HR (86%), and RPE+RR (92% and 55%) predicted TE in LT1, TT(50%) , LT2, and TW(25%) , respectively. At intensities from TT(50%) to TW(25%) , variables associated with brain activity seem to explain most of the RPE slope, and RPE (+HR and+RR) seems to predict the TE.