共查询到10条相似文献,搜索用时 93 毫秒
1.
Many physically active individuals have undertaken intermittent fasting to reduce their daily caloric intake. However, abstaining from meals for a specific length of time may lead to the acute disturbance of highly carbohydrate-dependent exercise performance. The purpose of this study was to observe the effect of 10 days of intermittent fasting on high-intensity type exercises, Wingate anaerobic (WT) and prolonged high-intensity time-to-exhaustion (HIT) cycling test. Twenty participants were randomised into an intermittent fasting (FAS) and a control group (CON). One day after baseline data collection on Day-0 where participants consumed their recommended daily caloric intake (FAS?=?2500?±?143?kcal?day?1; CON?=?2492?±?20?kcal?day?1) served over a course of five meals, the FAS group consumed only four meals where 40% was restricted by the omission of lunch (FAS?=?1500?±?55?kcal?day?1). This diet was then continued for 10 days. Data on exercise performance and other dependent variables were collected on Day-2, -4, -6, -8 and -10. A reduction in WT power in the FAS group was observed on Day-2 (821.74?±?66.07?W) compared to Day-0 (847.63?±?95.94?W) with a moderate effect size (p?.05, ES?=?0.4), while HIT time-to-exhaustion performance declined over the 10 days with a trend of recovery from a large to a minimum effect size (p?.05, ES?=?0.8–0.3). Body weight and triglyceride were consistently reduced in the FAS group (p?.01). The present study suggests that intermittent fasting must exceed 10 days to ensure that high-intensity performance does not deteriorate because this length of time seems to be required for effective adaptation to the new dietary regimen. 相似文献
2.
Mo’ath F. Bataineh Ali M. Al-Nawaiseh Mohammad H. Abu Altaieb David M. Bellar Omar S. Hindawi 《European Journal of Sport Science》2018,18(3):357-366
Mouth rinsing using a carbohydrate (CHO) solution has been suggested to improve physical performance in fasting participants. This study examined the effects of CHO mouth rinsing during Ramadan fasting on running time to exhaustion and on peak treadmill speed (Vpeak). In a counterbalanced crossover design, 18 sub-elite male runners (Age: 21?±?2 years, Weight: 68.1?±?5.7?kg, VO2max: 55.4?±?4.8?ml/kg/min) who observed Ramadan completed a familiarization trial and three experimental trials. The three trials included rinsing and expectorating a 25?mL bolus of either a 7.5% sucrose solution (CHO), a flavour and taste matched placebo solution (PLA) for 10?s, or no rinse (CON). The treatments were performed prior to an incremental treadmill test to exhaustion. Three-day dietary and exercise records were obtained on two occasions and analysed. Anthropometric characteristics were obtained and recorded for all participants. A main effect for mouth rinse on peak velocity (Vpeak) (CHO: 17.6?±?1.5?km/h; PLA: 17.1?±?1.4?km/h; CON: 16.7?±?1.2?km/h; P?.001, ηp2?=?0.49) and time to exhaustion (CHO: 1282.0?±?121.3?s; PLA: 1258.1?±?113.4?s; CON: 1228.7?±?98.5?s; P?=?.002, ηp2?=?0.41) was detected, with CHO significantly higher than PLA (P?.05) and CON (P?.05). Oxygen consumption, heart rate, respiratory exchange ratio, and rating of perceived exertion were not significantly different between treatments or trials (P?>?.05). Energy availability from dietary analysis, body weight, and fat-free mass did not change during the last two weeks of Ramadan (P?>?.05). This study concludes that carbohydrate mouth rinsing improves running time to exhaustion and peak treadmill speed under Ramadan fasting conditions. 相似文献
3.
Daniel M. Duvnjak-Zaknich Karen E. Wallman Brian T. Dawson Peter Peeling 《European Journal of Sport Science》2019,19(3):295-304
The aim of this study was to compare the impact of continuous (CON) and intermittent (INT) heat acclimation protocols on repeat-sprint performance, and to also assess the degree of performance decay following acclimation. Using a pair-matched, between subjects design, 16 trained male team sport athletes were allocated to either INT (8 sessions over 15 days) or CON acclimation (8 sessions over 8 days) groups. Participants performed a heat tolerance test (HTT) involving 60-min of repeat-sprint cycling with a 10-min half time break (in 35.3?±?0.7°C, 60.1?±?4.0%; RH) two days pre- (pre-HTT) and post-acclimation (post-HTT1). Decay was investigated with two further HTT's completed over the next two weeks (post-HTT2 and post-HTT3). Results showed the post-HTT1 performance variables [mean power (pre-HTT; INT?=?1002.07?±?173.74, CON?=?1057.10?±?180.07 / post-HTT1; INT?=?1097.11?±?186.85, CON?=?1163.77?±?184.65 W), mean power (W.kg?1), total work (kJ) and work (J.kg?1)] were greater than pre-HHT (p?0.001) after acclimation, with no differences between INT and CON. No differences in final core and mean skin temperatures or heart rate existed after INT or CON acclimation, however 30 min measures for thermal sensation, perceived thirst and ratings of perceived exertion (as well as the final measure) were lower in post-HTT1 (p?0.05) in CON. Performance and thermoregulatory responses in post-HTT2 and 3 were similar to post-HTT1 in both INT and CON. These results indicate that prolonged repeat-sprint exercise in the heat is improved after acclimation involving short, high-intensity cycling sessions using either CON or INT protocols, with performance well-maintained over the subsequent 2 weeks, despite removal of the heat stimulus. 相似文献
4.
Dace Reihmane Martin Gram Andreas Vigelsø Jørn Wulff Helge Flemming Dela 《European Journal of Sport Science》2016,16(8):1039-1046
Physical inactivity is a major contributor to low-grade systemic inflammation. Most of the studies characterizing interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α) release from exercising legs have been done in young, healthy men, but studies on inactivity in older people are lacking. The impact of 14 days of one-leg immobilization (IM) on IL-6 and TNF-α release during exercise in comparison to the contralateral control (CON) leg was investigated. Fifteen healthy men (age 68.1?±?1.1?year (mean?±?SEM); BMI 27.0?±?0.4 kg·m2; VO2max 33.3?±?1.6 ml·kg?1·min?1) performed 45?min of two-leg dynamic knee extensor exercise at 19.5?±?0.9 W. Arterial and femoral venous blood samples from the CON and the IM legs were collected every 15?min during exercise, and thigh blood flow was measured with ultrasound Doppler. Arterial plasma IL-6 concentration increased with exercise (rest vs. 45?min, main effect p?.05). IL-6 release increased with exercise (rest vs. 30?min, main effect p?.05). Furthermore, IL-6 release was borderline (main effect, p?=?.085, effect size 0.28) higher in the IM leg compared to the CON leg (288 (95% CI: 213–373) vs. 220 (95% CI: 152–299) pg·min?1, respectively). There was no release of TNF-α in either leg and arterial concentrations remained unchanged during exercise (p?>?.05). In conclusion, exercise induces more pronounced IL-6 secretion in healthy older men. Two weeks of unilateral immobilization on the other hand had only a minor influence on IL-6 release. Neither immobilization nor exercise had an effect on TNF-α release across the working legs in older men. 相似文献
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6.
Parkour is a modern physical activity that consists of using the environment, mostly urban, as a playground of obstacles. The aims of this study were (i) to investigate age, anthropometric and training characteristics of Parkour practitioners, called ‘traceurs’ and (ii) to assess jump performances and muscular characteristics of traceurs, compared to those of gymnasts and power athletes. The mean age of the population of traceurs studied (n?=?130) was 19.4?±?4.3 years, women represented 12.4% of the total field and mean training volume was 8.1?±?0.5?hours/week. Vertical and long jump performances were analysed on smaller samples of participants (four groups, n?=?15 per group); and eccentric (?90°?s?1, ?30°?s?1), concentric (30°?s?1, 90°?s?1) and isometric knee extensors torques were evaluated by means of an isokinetic dynamometer. Traceurs showed greater (P?.01) drop jump performance (64.9?±?1.5?cm) than gymnasts (60.9?±?1.1?cm) and greater (P?.001) counter movement jump with arms (59.2?±?1.5?cm) than power athletes (53.0?±?1.4?cm). Standing long jump performances were greater (P?.05) for traceurs (282.7?±?5.2?cm) compared to other athletes (gymnasts: 273.9?±?7.3?cm; power athletes: 261.3?±?6.7?cm). Eccentric knee extension torques were greater (P?.05) for traceurs compared to other athletes. This study revealed that Parkour training induces major development of jump and muscular skills. The use of such training has several practical applications as it provides a better resistance to high eccentric load and helps reinforce musculoskeletal structures. 相似文献
7.
Lachlan Mitchell Gary Slater Daniel Hackett Nathan Johnson Helen O’connor 《European Journal of Sport Science》2018,18(5):619-629
This study aimed to describe the body composition and physiological changes which take place during the in-season and recovery periods of a group of natural bodybuilders. Natural male bodybuilders (n?=?9) were assessed 16 (PRE16), 8 (PRE8), and 1 (PRE1) week(s) before, and 4 (POST4) weeks after a bodybuilding competition. Assessments included body composition, resting metabolic rate (RMR), serum hormones, and 7-day weighed food and training diaries. Change in parameters was assessed using repeated-measures analysis of variance. Dietary protein intake remained high throughout the study period (2.8–3.1?g?kg?1?d?1). Fat mass (FM) was significantly reduced from PRE16 to PRE1 (8.8?±?3.1 vs. 5.3?±?2.4?kg, P?.01). There was a small decrease in lean mass (LM) from PRE8 to PRE1 (71.8?±?9.1 vs. 70.9?±?9.1?kg, P?.05). No changes in RMR were observed (P?>?.05). Large reductions in total and free testosterone (16.4?±?4.4 vs. 10.1?±?3.6?nmol?L?1, P?.05; 229.3?±?72.4 vs. 116.8?±?76.9?pmol?L?1, P?.05), and insulin-like growth factor-1 (IGF-1) (27.0?±?7.7 vs. 19.9?±?7.6?nmol?L?1, P?.05) occurred between PRE16 and PRE1. LM and IGF-1 increased from PRE1 to POST4 (70.9?±?9.1 vs. 72.5?±?8.5?kg, P?.05; 19.9?±?7.6 vs. 25.4?±?9.3?nmol?L?1, P?.05). Despite substantial reductions in FM, participants maintained almost all of their LM. The reduction in anabolic hormone concentration is likely attributable to the prolonged negative energy balance, despite a high dietary protein intake. 相似文献
8.
Amelia Guadalupe-Grau Lorena Rodríguez-García Rafael Torres-Peralta David Morales-Álamo Jesús Gustavo Ponce-González Ismael Pérez-Suarez 《European Journal of Sport Science》2016,16(4):455-464
Objectives: This study was designed to investigate the association of gender, fibre type composition, and anaerobic performance with the basal skeletal muscle signalling cascades regulating muscle phenotype. Design: Muscle biopsies were obtained from 25 men and 10 women all young and healthy. Methods. Protein phosphorylation of Thr172AMPKα, Ser221ACCβ, Thr286CaMKII as well as total protein abundance of PGC-1α, SIRT1, and CnA were measured by Western blot and anaerobic performance by the Wingate test. Results: Percent type I myosin heavy chain (MHC I) was lower in men (37.1?±?10.4 vs. 58.5?±?12.5, P?.01). Total, free testosterone and free androgen index were higher in men (11.5, 36.6 and 40.6 fold, respectively, P?.01). AMPKα phosphorylation was 2.2-fold higher in men compared to women (P?.01). Total Ser221ACCβ and Thr286CaMKII fractional phosphorylation tended to be higher in men (P?=?.1). PGC1-α and SIRT1 total protein expression was similar in men and women, whereas CnA tended to be higher in men (P?=?.1). Basal AMPKα phosphorylation was linearly related to the percentage of MHC I in men (r?=?0.56; P?.01), but not in women. No association was observed between anaerobic performance and basal phosphorylations in men and women, analysed separately. Conclusion: In summary, skeletal muscle basal AMPKα phosphorylation is higher in men compared to women, with no apparent effect on anaerobic performance. 相似文献
9.
Christof A. Leicht Aris Papanagopoulos Sam Haghighat Steve H. Faulkner 《Journal of sports sciences》2017,35(17):1752-1758
Plasma heat shock protein 70 (HSP70) concentrations rise during heat stress, which can independently induce cytokine production. Upper body exercise normally results in modest body temperature elevations. The aim of this study was to investigate the impacts of additional clothing on the body temperature, cytokine and HSP70 responses during this exercise modality. Thirteen males performed 45-min constant-load arm cranking at 63% maximum aerobic power (62 ± 7%V?O2peak) in either a non-permeable whole-body suit (intervention, INT) or shorts and T-shirt (control, CON). Exercise resulted in a significant increase of IL-6 and IL-1ra plasma concentrations (P < 0.001), with no difference between conditions (P > 0.19). The increase in HSP70 from pre to post was only significant for INT (0.12 ± 0.11ng?mL?1, P < 0.01 vs. 0.04 ± 0.18 ng?mL?1, P = 0.77). Immediately following exercise, Tcore was elevated by 0.46 ± 0.29 (INT) and 0.37 ± 0.23ºC (CON), respectively (P < 0.01), with no difference between conditions (P = 0.16). The rise in mean Tskin (2.88 ± 0.50 and 0.30 ± 0.89ºC, respectively) and maximum heat storage (3.24 ± 1.08 and 1.20 ± 1.04 J?g?1, respectively) was higher during INT (P < 0.01). Despite large differences in heat storage between conditions, the HSP70 elevations during INT, even though significant, were very modest. Possibly, the Tcore elevations were too low to induce a more pronounced HSP70 response to ultimately affect cytokine production. 相似文献
10.
Attenuated performance during intense exercise with limited endogenous carbohydrate (CHO) is well documented. Therefore, this study examined whether caffeine (CAF) mouth rinsing would augment performance during repeated sprint cycling in participants with reduced endogenous CHO. Eight recreationally active males (aged 23?±?2?yr, body mass 84?±?4?kg, stature 178?±?7?cm) participated in this randomized, single-blind, repeated-measures crossover investigation. Following familiarization, participants attended two separate evening glycogen depletion sessions. The following morning, participants completed five, 6?s sprints on a cycle ergometer (separated by 24?s active recovery), with mouth rinsing either (1) a placebo solution or (2) a 2% CAF solution. During a fifth visit, participants completed the sprints without prior glycogen depletion. Repeated-measures ANOVA identified significant main effect of condition (CAF, placebo, and control [P?.05; effect size (ES)?=?0.850–0.897]), sprint (1–5 [P?.005; ES?=?0.871–0.986]), and interaction (condition?×?sprint [P?.05; ES?=?0.831–0.846]), for peak and mean power. The control condition exhibited the highest peak power (overall mean 760?±?77?W) and mean power (overall mean 699?±?83W) over the five sprints (P?.001 in both instances). CAF peak power (overall mean 643?±?79?W) was significantly greater than placebo (mean 573?±?79?W [P?.05; ES?=?0.850]). Additionally, CAF mean power (overall mean 589?±?80?W) was significantly greater than placebo (519?±?82?W [P?.05; ES?=?0.397]). These data indicate that mouth rinsing a caffeinated solution reduces decrements caused by CHO reduction, which may benefit athletes wishing to train in a low-CHO state. 相似文献