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Nicolajsen Hvid heeft een update geplaatst 5 dagen, 10 uren geleden
Research suggests that beet juice is beneficial during aerobic exercise. However, the impact of beet juice during primarily anaerobic exercise is equivocal. The purpose of this study was to determine the effects of acute beet juice supplementation on maximal intensity performance during 30-s and 60-s maximal-intensity cycling sprints. Using a double-blind, crossover-study design, 14 anaerobically trained male hockey players completed six Wingate cycling tests familiarization trials of a 30-s and 60-s Wingate test, followed by 30-s Wingate placebo/beet juice trials, and 60-s Wingate placebo/beet juice trials. Zilurgisertib fumarate Repeated measures ANOVAs were used to compare the change in power between conditions over the duration of each trial. Paired t-tests were run to compare performance between conditions of various work and power variables. One-way ANOVAs were utilized to compare the change between conditions of the 30-s test to the change between conditions of the 60-s test. Beet juice supplementation yielded no statistical differences from placebo in any of the measured variables during the 30-s or 60-s tests (p > 0.05). The percent change for fatigue index was significantly different between the 30-s and 60-s tests (p = 0.032) suggesting less fatigue with beet juice supplementation. Overall, beet juice did not improve maximal intensity performance during 30-s or 60-s cycling sprint tests. Performance during the 60-s bout was not impacted to a greater extent than the 30-s bout after beet juice supplementation. These results suggest that beet juice supplementation does not improve short-duration exercise performance in anaerobically trained athletes.Athletes with cervical level spinal cord injuries (SCI) have an impaired ability to thermoregulate during exercise, leading to an increased core temperature (Tcore) due to a decrease in sweat response. Elevated Tcore may result in premature onset of fatigue and decreased athletic performance. Therefore, precooling techniques that decrease Tcore before exercise may increase the storage capacity for metabolic heat production, thereby delaying the time before reaching a critically high Tcore. The purpose of this study was to investigate the effects of pre-exercise ice slurry ingestion as a precooling method in elite athletes with SCI during a wheelchair rugby match simulation. Employing a field-based, counterbalanced-design, participants were administered 6.8 g/kg of room temperature (PLB) or ice slurry (IS) beverage during a 20-minute precooling period, before engaging in a 50 and 60 minute on-court training session on day 1 and 2, respectively. Physiological measures, including Tcore and heart rate, and perceptual measures including gastrointestinal and thermal comfort, and rating of perceived exertion, were monitored throughout precooling (minutes 10, 20) and exercise (minutes 10-60). IS had a large effect on Tcore at the midpoint of exercise on day 1 (minute 30) (ES=0.73) and 2 (minute 40) (ES=1.17). Independent samples T-tests revealed significant differences in the perception of thermal comfort between IS and PLB at the midpoint of exercise on day 1 (minute 30) (p=0.04), but not day 2 (minute 40) (p=0.05), indicating that IS may help participants to feel cooler during exercise. Although further research is warranted, pre-exercise ice slurry ingestion may provide an effective means for delaying an increase in Tcore in some athletes with SCI during a wheelchair rugby match.Excessive anterior and posterior pelvic tilts (PT) angles are associated with overuse injuries of the lower limbs and of the lumbo-pelvic-hip complex. There is a lack of evidence that correlates anterior and posterior PT angles with limited hip internal rotation (IR) and external rotation (ER), and hip muscles torque ratios. The purpose of this study was to examine the correlation between averaged anterior/posterior PT angle in standing position and hip IR and ER range of motion (ROM), hip adductors and abductors (Add/Abd) torque ratio, and hip flexors and extensors (Flexor/Extensor) torque ratio. Twenty-six healthy participants participated in this study, fifteen females (22.0 ± 2.8 yrs, 163.5 ± 7.5 cm, 65.9 ± 10.4 kg) and eleven males (22.0 ± 2.2 yrs, 178.5 ± 4.5 cm, 78.4 ± 8.7 kg). Hip muscle torques were collected with an isokinetic dynamometer, five trials at 30 degrees per second (deg· s-1) and at 60 deg· s-1. The measurement of PT in standing natural position and hip IR and ER ROM in functional weight-bearing lunge position were recorded, using a 3D Motion Analysis System. There were no significant correlations between PT angle and hip IR and ER (p ≥ 0.05), no significant correlations between PT angle and hip Add/Abd torque ratio (p > 0.05), and no significant correlations between PT angle and hip Flexor/Extensor torque ratio (p > 0.05). The measurement of PT angle in standing natural position was not associated with hip IR and ER ROM and hip Add/Abd and Flexor/Extensor torque ratios, in healthy population.Significant asymmetries can exist between the lower limbs’ force production during the take-off phase of bilateral jumping exercises. Some studies have indicated that similar asymmetries can also exist during the landing phase. It has not been demonstrated if the magnitude of lower body asymmetry was similar between the landing (L) and take-off (TO) phases of bilateral jumping movements. The main purpose of this study was to compare the asymmetry measured during the L and TO phases of bilateral jumping exercises to determine if there was a difference in asymmetry between the phases. In order to quantify the degree of the asymmetry, the vertical ground reaction force (vGRF) produced by each leg was measured during execution of vertical-jump (VJ) and drop-jump (DJ) exercises. Eleven recreationally trained individuals completed three VJ and DJ trials while two force plates recorded vGRF. A two-way repeated measures ANOVA was used to compare the asymmetry levels with the phase (within- subject L and TO) and the exercise (within- subject VJ and DJ) being factors. A significant difference in the asymmetry was found between the L and TO phases (p less then .05). These findings suggested that there was greater asymmetry in the distribution of vGRF during landing than during take-off.