首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 140 毫秒
1.
The aim of this study was to compare the effects of two different intensity distribution training programmes (polarized (POL) and threshold (THR)) on aerobic performance, strength and body composition variables in ultra-endurance runners. Twenty recreationally trained athletes were allocated to POL (n?=?11; age: 40.6?±?9.7 years; height: 175.4?±?7?cm; weight: 73.5?±?10.8?kg; fat mass 18.4?±?6.0%; VO2max: 55.8?±?4.9?ml/kg/min) or THR group (n?=?9; age: 36.8?±?9.2 years; height: 178.5?±?4.2?cm; weight: 75.5?±?10.4?kg; fat mass 14.9?±?5.3%; VO2max: 57.1?±?5.2?ml/kg/min) and performed the 12 weeks training programme. Both programmes had similar total time and load but a different intensity distribution (POL?=?79.8?±?2.1% in Zone 1; 3.9?±?1.9% in Zone 2; 16.4?±?1.5% in Zone 3; THR?=?67.2?±?4.6% in Zone 1; 33.8?±?4.6% in Zone 2; 0% in Zone 3). Body composition, isokinetic strength and aerobic running performance were measured before and after each programme. Both groups decreased fat mass after training (POL= Δ–11.2%; p?=?.017; ES?=?0.32; THR= Δ–18.8%; p?p?=?0.003; ES?=?0.71) and 12?km/h (Δ–4.5%; p?=?.026; ES?=?0.73) and running time to exhaustion (Δ2.4%; p?=?.011; ES?=?0.33). No changes were observed in strength and no significant differences were observed between the group in any variable. Compared with THR distribution, 12 weeks of POL training efficiently improves aerobic performance in recreational ultra-endurance runners.  相似文献   

2.
The goal of this randomized, double-blind, cross-over study was to assess the acute effects of caffeine ingestion on muscular strength and power, muscular endurance, rate of perceived exertion (RPE), and pain perception (PP) in resistance-trained men. Seventeen volunteers (mean?±?SD: age?=?26?±?6 years, stature?=?182?±?9?cm, body mass?=?84?±?9?kg, resistance training experience?=?7?±?3 years) consumed placebo or 6?mg?kg?1 of anhydrous caffeine 1?h before testing. Muscular power was assessed with seated medicine ball throw and vertical jump exercises, muscular strength with one-repetition maximum (1RM) barbell back squat and bench press exercises, and muscular endurance with repetitions of back squat and bench press exercises (load corresponding to 60% of 1RM) to momentary muscular failure. RPE and PP were assessed immediately after the completion of the back squat and bench press exercises. Compared to placebo, caffeine intake enhanced 1RM back squat performance (+2.8%; effect size [ES]?=?0.19; p?=?.016), which was accompanied by a reduced RPE (+7%; ES?=?0.53; p?=?.037), and seated medicine ball throw performance (+4.3%, ES?=?0.32; p?=?.009). Improvements in 1RM bench press were not noted although there were significant (p?=?.029) decreases in PP related to this exercise when participants ingested caffeine. The results point to an acute benefit of caffeine intake in enhancing lower-body strength, likely due to a decrease in RPE; upper-, but not lower-body power; and no effects on muscular endurance, in resistance-trained men. Individuals competing in events in which strength and power are important performance-related factors may consider taking 6?mg?kg?1 of caffeine pre-training/competition for performance enhancement.  相似文献   

3.
This study aimed to determine which contractile properties measured by tensiomyography (TMG) could better differentiate athletes with high- and low-power values, as well as to analyse the relationship between contractile properties and power production capacity. The contractile properties of the vastus medialis (VM), rectus femoris (RF) and vastus lateralis (VL) of an Olympic women’s Rugby Sevens team (n?=?14) were analysed before a Wingate test in which their peak power output (PPO) was determined. Athletes were then divided into a high-power (HP) and a low-power (LP) group. HP presented an almost certainly higher PPO (9.8?±?0.3 vs. 8.9?±?0.4 W kg?1, ES?=?3.00) than LP, as well as a very likely lower radial displacement (3.39?±?1.16 vs. 5.65?±?1.50?mm, ES?=?1.68) and velocity of deformation (0.08?±?0.02 vs. 0.13?±?0.03 mm ms?1, ES?=?1.87) of the VL. A likely lower time of delay was observed in HP for all analysed muscles (ES?>?0.60). PPO was very largely related to the radial displacement (r?=??0.75, 90% CI?=??0.90 to ?0.44) and velocity of deformation (r?=??0.70, 90% CI?=??0.87 to ?0.34) of the VL. A large correlation was found between PPO and the time of delay of the VL (r?=??0.61, 90% CI?=??0.84 to ?0.22). No correlations were found for the contractile properties of RF or VM. These results highlight the importance of VL contractile properties (but not so much those of RF and VM) for maximal power production and suggest TMG as a practical technique for its evaluation.  相似文献   

4.
This investigation examined the oxidative stress (F2-Isoprostane; F2-IsoP) and inflammatory (interleukin-6; IL-6) responses to repeat-sprint training in hypoxia (RSH). Ten trained male team sport athletes performed 3(sets)*9(repetitions)*5?s cycling sprints in simulated altitude (3000?m) and sea-level conditions. Mean and peak sprint power output (MPO and PPO) were recorded, and blood samples were collected pre-exercise, and again at 8 and 60?min post-exercise. Both MPO and PPO were significantly reduced in hypoxia (compared to sea-level) in the second (MPO: 855?±?89 vs. 739?±?95?W, p?=?.006; PPO: 1024?±?114 vs. 895?±?112?W, p?=?.010) and third (MPO: 819?±?105 vs. 686?±?83?W, p?=?.008; PPO: 985?±?125 vs. 834?±?99?W, p?=?.008) sets, respectively. IL-6 was significantly increased from pre- to 1?h post-exercise in both hypoxia (0.7?±?0.2 vs. 2.4?±?1.4?pg/mL, p?=?.004) and sea-level conditions (0.7?±?0.2 vs. 1.6?±?0.3?pg/mL, p?d?=?0.80) suggesting higher IL-6 levels of post-hypoxia. F2-IsoP was significantly lower 1?h post-exercise in both the hypoxic (p?=?.005) and sea-level (p?=?.002) conditions, with no differences between trials. While hypoxia can impact on exercise intensity and may result in greater post-exercise inflammation, it appears to have little effect on oxidative stress. These results indicate that team sport organisations with ready access to hypoxic training facilities could confidently administer RSH without significantly increasing the post-exercise inflammatory or oxidative stress response.  相似文献   

5.
We sought to determine the sex-specific effects of an acute bout of free-weight resistance exercise (RE) on pulse wave reflection (aortic blood pressures, augmentation index (AIx), AIx at 75?bpm (AIx@75), augmentation pressure (AP), time of the reflected wave (Tr), subendocardial viability ratio (SEVR)), and aortic arterial stiffness in resistance-trained individuals. Resistance-trained men (n?=?14) and women (n?=?12) volunteered to participate in the study. Measurements were taken in the supine position at rest, and 10 minutes after 3 sets of 10 repetitions at 75% 1-repetition maximum on the squat, bench press, and deadlift. A 2?×?2?×?2 ANOVA was used to analyse the effects of sex (men, women) across condition (RE, control) and time (rest, recovery). There were no differences between sexes across conditions and time. There was no effect of the RE on brachial or aortic blood pressures. There were significant condition?×?time interactions for AIx (rest: 12.1?±?7.9%; recovery: 19.9?±?10.5%, p?=?.003), AIx@75 (rest: 5.3?±?7.9%; recovery: 24.5?±?14.3%, p?=?.0001), AP (rest: 4.9?±?2.8?mmHg; recovery: 8.3?±?6.0?mmHg, p?=?.004), and aortic arterial stiffness (rest: 5.3?±?0.6?ms; recovery: 5.9?±?0.7?ms, p?=?.02) with significant increases during recovery from the acute RE. There was also a significant condition?×?time for time of the reflected wave (rest: 150?±?7?ms; recovery: 147?±?9?ms, p?=?.02) and SEVR (rest: 147?±?17%; recovery: 83?±?24%, p?=?.0001) such that they were reduced during recovery from the acute RE compared to the control. These data suggest that an acute bout of RE increases AIx, AIx@75, and aortic arterial stiffness similarly between men and women without significantly altering aortic blood pressures.  相似文献   

6.
The aim of the present study was to evaluate the effects of a 12-week home-based strength, explosive and plyometric (SEP) training on the cost of running (Cr) in well-trained ultra-marathoners and to assess the main mechanical parameters affecting changes in Cr. Twenty-five male runners (38.2?±?7.1 years; body mass index: 23.0?±?1.1?kg·m?2; V˙O2max: 55.4?±?4.0 mlO2·kg?1·min?1) were divided into an exercise (EG?=?13) and control group (CG?=?12). Before and after a 12-week SEP training, Cr, spring-mass model parameters at four speeds (8, 10, 12, 14?km·h?1) were calculated and maximal muscle power (MMP) of the lower limbs was measured. In EG, Cr decreased significantly (p?<?.05) at all tested running speeds (?6.4?±?6.5% at 8?km·h?1; ?3.5?±?5.3% at 10?km·h?1; ?4.0?±?5.5% at 12?km·h?1; ?3.2?±?4.5% at 14?km·h?1), contact time (tc) increased at 8, 10 and 12?km·h?1 by mean +4.4?±?0.1% and ta decreased by ?25.6?±?0.1% at 8?km·h?1 (p?<?.05). Further, inverse relationships between changes in Cr and MMP at 10 (p?=?.013; r?=??0.67) and 12?km·h?1 (p?<?.001; r?=??0.86) were shown. Conversely, no differences were detected in the CG in any of the studied parameters. Thus, 12-week SEP training programme lower the Cr in well-trained ultra-marathoners at submaximal speeds. Increased tc and an inverse relationship between changes in Cr and changes in MMP could be in part explain the decreased Cr. Thus, adding at least three sessions per week of SEP exercises in the normal endurance-training programme may decrease the Cr.  相似文献   

7.
This study investigated how learning a passing skill with futsal or soccer task constraints influenced transfer to a new task. Futsal (n?=?24, 13.6?±?1.2 years old, 7.0?±?1.6 years of experience) and soccer (n?=?24, 13.6?±?1.2 years old, 6.8?±?1.2 years of experience) players performed two 5v5?+?goalkeeper modified games – a futsal-like task (small playing area with the futsal ball) and soccer-like task (large playing area with the soccer ball). Participants’ passing accuracy and their orientation of attention were assessed during the two tasks. The futsal group improved their passing accuracy (ES?=?0.75?±?0.61) from the futsal-like to the soccer-like task, and they were more accurate than soccer players (ES?=?2.98?±?2.96). Conversely, the soccer group’s passing accuracy remained stable across the two tasks (ES?=?0.10?±?0.52) and it was similar to the futsal group in the futsal-like task (ES?=?0.58?±?1.93). This indicates a higher magnitude of transfer (and adaptability) from performing passes in a small playing area with short time to act – futsal task constraints – to a larger playing area with longer time – soccer task constraints – than vice-versa. Furthermore, the futsal group showed a higher adaptation of attention orientation to the affordances that emerged with the soccer task constraints, which is suggested to be one of the main mechanisms promoting skill transfer. These results encourage soccer practitioners to introduce futsal task constraints to fast-track players’ ability to functionally adapt perception–action coupling.  相似文献   

8.
Physiological or performance tests are routinely utilised to assess athletes’ recovery. At present, the ideal tool to assess recovery remains unknown. Therefore, the aim of this systematic review was to examine the change in creatine kinase (CK) and neuromuscular function as measured via a countermovement jump (CMJ) following a match in the contact codes of football. A comprehensive search of databases was undertaken with RevMan (V 5.3) used for statistical analysis. Our results demonstrated that CK pre- versus post-match (standardised mean difference (SMD)?=?0.90, 95% CI?=?0.50 to 1.31, p?p?p?p?=?.03), and pre- versus 24?h post-match (SMD?=??0.80, 95% CI?=??1.31 to ?0.28, p?=?.002) decreased significantly. There was a significant relationship between the change in CK and the change in CMJ PP from immediately pre to immediately post (r?=??0.924, p?=?.025), and between CMJ immediately following a match and 24?h CK change (r?=??0.983, p?=?.017). In conclusion, CK levels increase and performance in the CMJ decreases following a match of a contact code of football. The identification of this relationship may allow coaching staff to implement a standalone measure of recovery.  相似文献   

9.
Abstract

The aim of this study was to analyse the pacing strategies adopted by elite male and female marathon runners when setting every world record since 1998. For data analysis, the total distance of the marathon was divided into eight sections of 5?km and a final section of 2.195?km, and the relative average speed of each section was calculated individually. Female athletes maintained similar speeds in the first and second half of the marathon (ES?=?0.22, small effect, p?=?0.705), whereas male athletes increased their speed as the marathon progressed (ES?=?1.18, moderate effect, p?=?0.011). However, no differences were observed between men and women in either the first (ES?=?0.56, small effect, p?=?0.290), or in the second half of the marathon (ES?=?0.60, moderate effect, p?=?0.266). When comparing the women’s world records (1998–2003) vs. men’s records (1998–2018) by sections, we observed differences at the beginning of the race (second section, ES?=?0.89, moderate effect) and at the end (last section, ES?=?0.87, moderate effect). The pace variations during the race were similar between male athletes and that of women with male pacemakers (1.53%?±?0.60 vs. 1.68%?±?0.84, respectively). However, a trend towards higher pace variations during the race in the female records with female pacemakers was observed (2.28%?±?0.95). This study shows how male and female marathon records in the last 20 years have been set using different pacing strategies. While men used a negative strategy (faster finishing), women used a less uniform pacing strategy.  相似文献   

10.
Abstract

This study aimed to understand the kinematic and kinetic differences between two sprint starts: block and split-stance standing. Fourteen sub-elite male sprinters (100 m time: 11.40?±?0.39?s) performed block and split-stance standing starts sprints over 30 m of in-ground force platforms in a randomised order. Independent t-tests and repeated measures mixed model analysis of variance were used to analyse the between-condition variables across conditions, and over four step phases. Block start sprints resulted in significantly (p?<?.05) faster 5 m (5.0%, effect size [ES]?=?0.89) and 10?m (3.5%, ES?=?0.82) times, but no significant differences were found at 20 and 30?m. No significant differences were found in any kinematic measure between starting positions. However, block starts resulted in significantly (p?<?.001) greater propulsive impulses (6.8%, ES?=?1.35) and net anterior-posterior impulses (6.5%, ES?=?1.12) during steps 1–4, compared to the standing start. Block starts enable athletes to produce a greater amount of net anterior-posterior impulse during early accelerated sprinting, resulting in faster times up to 10 m. When seeking to improve initial acceleration performance, practitioners may wish to train athletes from a block start to improve horizontal force production.  相似文献   

11.
The potential effect of fatigue on stroke production in tennis players is still controversial. The aim of this study was to analyse the tennis serve speed and accuracy in prolonged male professional matches played on grass courts. We analysed tennis serve statistics from five-set Wimbledon matches (n?=?15; 30 players). Results showed that match duration averaged 208.3?±?28.3?min. The overall serve speed was 177.0?±?10.2?km/h in the first set and 176.1?±?11.7?km/h in the fifth set (p?=?.34). The difference of all accuracy values of first set serves was not significantly different from those of the fifth set: percentage of valid first serves, 63.1?±?11.1% vs. 62.3?±?11.8%, respectively (p?=?.78); percentage of “aces”, 11.2?±?9.1% vs. 10.0?±?8.9%, respectively (p?=?.39); percentage of “winners”, 2.6?±?7.6% vs. 1.2?±?2.2%, respectively (p?=?.36); percentage of “double faults”, 2.8?±?3.0% vs. 2.8?±?3.4% (p?=?.97). In conclusion, tennis players were able to maintain constant serve speed and accuracy over five-set matches played on grass courts. Professional tennis players are capable of overcoming fatigue and/or make movement adjustments to effectively perform complex technical strokes like the serve throughout matches played on grass courts lasting more than 3?h in average.  相似文献   

12.
This study investigated protein kinase activation and gene expression of angiogenic factors in response to low-load resistance exercise with or without blood flow restriction (BFR). In a repeated measures cross-over design, six males performed four sets of bilateral knee extension exercise at 20% 1RM (reps per set?=?30:15:15:continued to fatigue) with BFR (110?mmHg) and without (CON). Muscle biopsies were obtained from the vastus lateralis before, 2 and 4?h post-exercise. mRNA expression was determined using real-time RT–PCR. Protein phosphorylation/expression was determined using Western blot. p38MAPK phosphorylation was greater (p?=?0.05) at 2?h following BFR (1.3?±?0.8) compared to CON (0.4?±?0.3). AMPK phosphorylation remained unchanged. PGC-1α mRNA expression increased at 2?h (5.9?±?1.3 vs. 2.1?±?0.8; p?=?0.03) and 4?h (3.2?±?0.8 vs. 1.5?±?0.4; p?=?0.03) following BFR exercise with no change in CON. PGC-1α protein expression did not change following either exercise. BFR exercise enhanced mRNA expression of vascular endothelial growth factor (VEGF) at 2?h (5.2?±?2.8 vs 1.7?±?1.1; p?=?.02) and 4?h (6.8?±?4.9 vs. 2.5?±?2.7; p?=?.01) compared to CON. mRNA expression of VEGF-R2 and hypoxia-inducible factor 1α increased following BFR exercise but only eNOS were enhanced relative to CON. Matrix metalloproteinase-9 mRNA expression was not altered in response to either exercise. Acute low-load resistance exercise with BFR provides a targeted angiogenic response potentially mediated through enhanced ischaemic and shear stress stimuli.  相似文献   

13.
Objective: The purpose of the present study was to analyze whether improvements in fast walking speed induced by resistance training (RT) are associated with changes in body composition, muscle quality, and muscular strength in older women. Methods: Twenty-three healthy older women (69.6?±?6.4 years, 64.95?±?12.9?kg, 1.55?±?0.07?m, 27.06?±?4.6?kg/m²) performed a RT program for 8 weeks consisting of 8 exercises for the whole body, 3 sets of 10–15 repetitions maximum, 3 times a week. Anthropometric, body composition (fat-free mass [FFM], skeletal muscle mass [SMM], legs lean soft tissue [LLST], fat mass), knee extension muscular strength (KE1RM), muscle quality index (MQI [KE1RM/LLST]), and 10-meter walking test (10-MWT) were performed before and after the intervention. Results: Significant (P?<?.05) changes were observed from pre- to post-training for FFM (+1.6%), MQI (+7.2%), SMM (+2.4%), LLST (+1.8%), KE1RM (+8.6%), fat mass (?1.4%), and time to perform 10-MWT (?3.7%). The percentage change in 10-MWT was significantly associated with percentage change in MQI (r?=??0.46, P?=?.04) and KE1RM (r?=??0.45, P?=?.04), however not associated percentage of changes in SMM (r?=?0.01, P?=?.97), LLST (r?=??0.22, P?=?.33), and body fat (r?=?0.10, P?=?.66). Conclusion: We conclude that the improvement in the 10-MWT after an 8-week RT program is associated with increases in lower limb muscular strength and muscle quality, but not with muscle mass or body fat changes in older women.  相似文献   

14.
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?p?p?相似文献   

15.
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?P?P?P?P?P?相似文献   

16.
Research to enhance running performance has led to the design of a leaf spring-structured midsole shoe (LEAF). In treadmill running, it has been shown that LEAF led to an increased running economy and increased stride length (SL) through a horizontal foot shift during stance compared to a standard foam shoe (FOAM). The purpose of this study was to analyse whether (a) these findings can also be observed in overground running and (b) relations exist between spatio-temporal variables and running economy. Ten male long-distance heel-strike runners ran at their individual 2?mmol/l blood lactate speed with LEAF and FOAM in randomized order. Kinematic data were recorded with an inertial measurement unit synchronized with 2D video. Oxygen consumption was measured using an automated metabolic gas analysis system. Blood lactate was collected after each run. The strike pattern was unaffected by LEAF. SL was increased by 0.9?±?1.1?cm (95% CI 0.2 to 1.5; p?=?.040; dz?=?0.76), stride rate (SR) was reduced by ?0.4?±?0.3?strides/min (95% CI ?0.6 to ?0.1; p?=?.029; dz?=?0.82) and oxygen consumption tended to be reduced by 1% (?0.4?±?0.6?ml/min/kg; 95% CI ?0.8 to 0.0; p?=?.082; dz?=?0.62) when running with LEAF compared to FOAM. Changes in oxygen consumption in LEAF were correlated with SL (r?=?0.71; p?=?.022) and SR (r?=??0.68; p?=?.031). It can be concluded that LEAF has the potential to cause small changes in spatio-temporal variables during running. Runners increasing SL and decreasing SR in response to LEAF can achieve small improvements in running economy, which is beneficial in terms of performance.  相似文献   

17.
Abstract

Hypoxic training methods are increasingly being used by researchers in an attempt to improve performance in normoxic ambients. Moreover, previous research suggests that resistance training in hypoxia can cause physiological and muscle adaptations. The primary aim of this study was to compare the effects of 8 weeks of high-intensity resistance circuit-based (HRC) training in hypoxia on body composition and strength performance. The secondary aim was to examine the effects of HRC on metabolic parameters. Twenty-eight male participants were randomly assigned to either hypoxia (Fraction of inspired oxygen [FIO2]?=?15%; HRChyp: n?=?15; age: 24.6?±?6.8 years; height: 177.4?±?5.9?cm; weight: 74.9?±?11.5?kg) or normoxia [FIO2]?=?20.9%; HRCnorm: n?=?13; age: 23.2?±?5.2 years; height: 173.4?±?6.2?cm; weight: 69.4?±?7.4?kg) groups. Training sessions consisted of two blocks of three exercises (Block 1: bench press, leg extension and front pull down; Block 2: deadlift, elbow flexion and ankle extension). Each exercise was performed at six repetition maximum. Rest periods lasted for 35-s between exercises, 3-min between sets and 5-min between blocks. Participants exercised twice weekly for 8 weeks, and body composition, strength and blood tests were performed before and after the training program. Lean body mass and bone mineral density significantly increased over time in the HRChyp (p?<?.005; ES?=?0.14 and p?<?.014; ES?=?0.19, respectively) but not in the HRCnorm after training. Both groups improved their strength performance over time (p?<?.001), but without group effect differences. These results indicate that simulated hypoxia during HRC exercise produced trivial effects on lean body mass and bone mineral density compared to normoxia.  相似文献   

18.
Scrummaging is a major component of Rugby Union gameplay. Successful scrummaging is dependent on the coordination of the forward players and the strength of the eight individuals. The study aim was to determine whether individual scrummaging kinetics and other candidate factors associated with scrummaging performance discriminate team scrum performances. Sixteen club-level forwards (stature: 1.80?±?0.1?m; mass: 99.0?±?18.2?kg) were initially divided into two scrummaging packs. A total of 10 various scrum permutations were tested, where players were randomly swapped between the two packs. Winning scrums were determined by two observers on opposite sides of the scrum. Fatigue (100?mm visual analogue scale (VAS)) and scrummaging effort (6–20 rating of perceived exertion (RPE)) were assessed following each scrum contest. Individual scrummaging kinetics were acquired through an instrumented scrum ergometer and muscular power indicated through vertical jump heights. Student’s t-tests were used to differentiate between winning and losing scrum packs. VAS and RPE were assessed using repeated measures ANOVAs. Winning scrum packs had significantly larger combined force magnitudes (p?<?.002), regardless of the player contribution calculations. Additionally, winning packs had less individual movement (p?=?.033) and higher combined vertical jump heights (p?<?.001) but were not significantly heavier (p?=?.759) than losing scrum packs. While perceived VAS and RPE values progressively increased (p?<?.001), no differences in the individual scrum magnitudes were observed between the 1st and 10th scrum (p?=?.418). The results indicated that the combination of individual forces, variation in movement and factors related to scrummaging performance, such as vertical jump height, were associated with team scrummaging success.  相似文献   

19.
To formulate individualized dietary strategies for jockeys, it is vital that energy requirements are quantified. We measured total energy expenditure (TEE) over two separate weeks in spring and summer using doubly labelled water in a group of male flat jockeys (n?=?8, 36.9?±?5.7 years, 164?±?8?cm, 54.6?±?2.5?kg). Total energy intake (TEI) was self-recorded, as were all riding and structured exercise activity. Mean daily TEE was 10.83 (±2.3) and 10.66 (±1.76) MJ, (p?=?.61) respectively. Self-reported TEI were 6.03 (±1.7) and 5.37 (±1.1) MJ (p?=?.40), respectively, and were significantly lower than TEE (p?=?.01). Mean race rides were 17 (±6) and 13 (±3; p?=?0.37) and horses ridden at morning exercise were 8 (±6) and 7 (±4; p?=?.77) respectively. Additional structured exercise was 76.25 (±95.1) and 52.5 (±80.9) min per week (p?=?.35), respectively. At the individual level, TEE was related to body mass and the level of non-racing physical activity, but not riding. Physical activity levels for TEE were 1.76 (±0.37) and 1.69 (±0.27; p?=?.59) and appear modest when compared with other athletes, and similar to age-matched non-athletes, suggesting that conventional sport-specific nutritional recommendations do not appear applicable. The large discrepancy between TEE and TEI suggests significant under reporting of dietary intake. These data now provide an appropriate framework from which to formulate jockey nutritional guidelines to promote the ability to achieve the daily weight target and improve athlete welfare.  相似文献   

20.
The aim of the present study was to compare the effect of an increasing-distance, interval-training programme and a decreasing-distance, interval-training programme, matched for total distance, on aerobic and anaerobic physiological indices. Forty physical education students were randomly assigned to either the increasing- or decreasing-distance, interval-training group (ITG and DTG), and completed two similar relevant sets of tests before and after six weeks of training. One training programme consisted of increasing-distance interval-training (100–200–300–400–500?m) and the other decreasing-distance interval training (500–400–300–200–100?m). While both training programmes led to a significant improvement in VO2 max (ES?=?0.83–1.25), the improvement in the DTG was significantly greater than in the ITG (14.5?±?3.6 vs. 7.8?±?3.2%, p?<?.05). In addition, while both training programmes led to a significant improvement in all anaerobic indices (ES?=?0.83–1.63), the improvements in peak power (15.7?±?7.8 vs. 8.9?±?4.7), mean power (10.6?±?5.4 vs. 6.8?±?4.4), and fatigue index (18.2?±?10.9 vs. 7.0?±?14.2) were significantly greater in the DTG compared to the ITG (p?<?.05). The main finding of the present study was that beyond the significant positive effects of both training programmes on aerobic and anaerobic fitness, the DTG showed significant superiority over the ITG in improving aerobic and anaerobic performance capabilities. Coaches and athletes should therefore be aware that, in spite of identical total work, an interval-training programme might induce different physiological impacts if the order of intervals is not identical.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号