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1.
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   

2.
The purpose of the study was to examine the perspectives of both academics and practitioners in relation to forming applied collaborative sport science research within team sports. Ninety-three participants who had previously engaged in collaborative research partnerships within team sports completed an online survey which focused on motivations and barriers for forming collaborations using blinded sliding scale (0–100) and rank order list. Research collaborations were mainly formed to improve the team performance (Academic: 73.6?±?23.3; Practitioner: 84.3?±?16.0; effect size (ES?=?0.54), small). Academics ranked journal articles’ importance significantly higher than practitioners did (Academic: Mrank?=?53.9; Practitioner: 36.0; z?=??3.18, p?=?.001, p?q). However, practitioners rated one-to-one communication as more preferential (Academic: Mrank?=?41.3; Practitioner 56.1; z?=??2.62, p?=?.009, p?q). Some potential barriers were found in terms of staff buy in (Academic: 70.0?±?25.5; Practitioner: 56.8?±?27.3; ES?=?0.50, small) and funding (Academic: 68.0?±?24.9; Practitioner: 67.5?±?28.0; ES?=?0.02, trivial). Both groups revealed low motivation for invasive mechanistic research (Academic: 36.3?±?24.2; Practitioner: 36.4?±?27.5; ES?=?0.01, trivial), with practitioners have a preference towards ‘fast’ type research. There was a general agreement between academics and practitioners for forming research collaborations. Some potential barriers still exist (e.g. staff buy in and funding), with practitioners preferring ‘fast’ informal research dissemination compared to the ‘slow’ quality control approach of academics.  相似文献   

3.
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   

4.
Irisin is a myokine that is thought to be secreted in response to exercise that may help to prevent obesity and maintain normal glucose metabolism. In this study we investigated the associations between irisin and glucose homeostasis in middle-aged, overweight and obese men (n?= 144) with impaired glucose regulation, and the impact of exercise training on these relationships. The participants underwent 12 weeks of resistance or aerobic (Nordic walking) exercise training three times per week, 60 minutes per session. Venous blood (n?=?105) and skeletal muscle samples (n?=?45) were obtained at baseline and post-intervention. Compared to controls, Nordic walking, but not resistance training, increased irisin levels in plasma (9.6?±?4.2%, P?=?0.014; 8.7?± 4.9%, P?=?0.087; respectively) compared to controls. When considering all subjects, baseline irisin correlated positively with atherogenic index of plasma (r?=?0.244, P?=?0.013) and 2-hour insulin levels (r?=?0.214, P?=?0.028), and negatively with age (r?=??0.262, P?=?0.007), adiponectin (r?=??0.240, P?=?0.014) and McAuley index (r?=??0.259, P?=?0.008). Training-induced FNDC5 mRNA changes were negatively correlated with HbA1c (r?=??0.527, P?=?0.030) in the resistance training group and with chemerin in the Nordic walking group (r?=??0.615, P?=?0.033). In conclusion, 12-weeks of Nordic walking was more effective than resistance training in elevating plasma irisin, in middle-aged men with impaired glucose tolerance. Thus, the change in irisin in response to exercise training varied by the type of exercise but showed limited association with improvements in glucose homeostasis.  相似文献   

5.
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   

6.
The aim of the study was to compare the effect of resistance training (RT) frequencies of five times (RT5), thrice- (RT3) or twice- (RT2) weekly in muscle strength and hypertrophy in young men. Were used a within-subjects design in which 20 participants had one leg randomly assigned to RT5 and the other to RT3 or to RT2. 1?RM and muscle cross-sectional area (CSA) were assessed at baseline, after four (W4) and eight (W8) RT weeks. RT5 resulted in greater total training volume (TTV) than RT3 and RT2 (P?=?.001). 1?RM increased similarly between protocols at W4 (RT5: 55?±?9?Kg, effect size (ES): 1.18; RT3: 51?±?11?Kg, ES: 0.80; RT2: 54?±?7?Kg, ES: 1.13; P?P?2, ES: 0.54; RT3: 22.0?±?4.6?cm2, ES: 0.19; RT2: ES: 0.25; 23.8?±?3.8?cm2; P?2; ES: 0.69; RT3: 23.6?±?4.2?cm2, ES: 0.58; RT2: 25.5?±?3.7?cm2; ES: 0.70; P?2; RT3: 21.2?±?4.0?cm2; RT2: 22.9?±?3.8?cm2). Performing RT5, RT3 and RT2 a week result in similar muscle strength increase and hypertrophy, despite higher TTV for RT5.  相似文献   

7.
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   

8.
Training load (TL) and recovery should be in optimal balance to obtain maximal performance gains. We aimed to study sleep as a recovery technique and its relationship with TL and performance in elite athletes. Twenty-six elite female artistic gymnasts were divided into an under 13 (n?=?6), an under 14 (n?=?6), a junior (n?=?7; 14–15y) and a senior (=World Championship (WC) competitors, n?=?7; ≥16y) category. Sleep, through sleep logs, and training parameters, using the session Rate of Perceived Exertion (sRPE) scale, were monitored to calculate total sleep time (TST), sleep efficiency (SE), TL, monotony and strain. Performance of WC competitors was evaluated through coach and WC qualification ranking. For the entire group, TST (effect sizes (ES)?=??1.12, confidence intervals (CI)?=??60:?47, P?P?=?.022) were shorter during week than weekend nights. TST and SE were highest in youngest gymnasts (P?P?P?P?P?=?.030). TST correlated with coach ranking (r?=??0.857, P?=?.014). Higher TL correlated with worse WC (r?=?0.829, P?=?.042) and coach (r?=?0.893, P?=?.007) ranking. This research in elite gymnasts indicated associations between decreased TST, augmented TL and inferior performance. Optimizing sleep and TL may therefore represent strategies to enhance performance.  相似文献   

9.
Abstract

The objective of this study was to determine the relationship between different variables measured with a force plate during the swimming start push-off phase and start performance presented by times to 5, 10 and 15?m. Twenty-one women from the Slovenian national swimming team performed two different swim starts (freestyle and undulatory) on a portable force plate to a distance further than 15?m. Correlations between push-off variables and times to 5, 10 and 15?m were quantified through Pearson's product-moment correlation coefficient (r). The variables that significantly correlated (p?<?.05) to all times measured in the two starts performed were: average horizontal acceleration (freestyle: r?=??0.58 to ?0.71; and undulatory: r?=??0.55 to ?0.66), horizontal take-off velocity (freestyle: r?=??0.56 to ?0.69; and undulatory: r?=??0.53 to ?0.67) and resultant take-off velocity (freestyle: r?=??0.53 to ?0.65; and undulatory: r?=??0.52 to ?0.61). None of the variables derived from the vertical force were correlated to swimming start performance (p?>?.05). Based on the results of this study, we can conclude that horizontal take-off velocity and average horizontal acceleration (calculated as the average horizontal force divided by swimmer's body mass) are the variables most related to swimming start performance in experienced swimmers, and therefore could be the preferred measures to monitor swimmers’ efficiency during the push-off phase.  相似文献   

10.
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   

11.
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   

12.
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   

13.
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14.
Activation of the hamstrings has been discussed as a measure for reducing strain on the ACL during jump landings in alpine skiing. The current study tested the hypothesis that hamstring and quadriceps activation can be voluntarily increased by the athlete. Specifically, two different instructions – to increase hamstring activation or to increase upper-leg co-contraction – were compared to normal landings. Eight members of the German national and junior national squad in freestyle skiing (age 19.6 ± 3.8 years; weight 66.1 ± 13.2 kg; height 172.2 ± 7.7 cm) performed 12 jump landings on a prepared run, 4 with no specific instruction, 4 with the instruction to generally activate the thigh muscles, and 4 with the instruction to specifically activate the hamstrings. Electromyographic (EMG) signals were recorded on the biceps femoris (BF), semitendinosus (ST), vastus lateralis (VL), rectus femoris (RF) and vastus medialis (VM). EMG activation levels were integrated over three landing phases and analysed with a repeated measures ANOVA. The instruction produced a significant main effect in ST (p = .026), VM (p = .032) and RF (p = .001). Contrary to previous research, the current study suggests that hamstring muscle activation levels can be voluntarily increased during jump landing, particularly in co-activation with its antagonists.  相似文献   

15.
Abstract

To determine if unilateral measures of muscle architecture in the rectus femoris (RF) and vastus lateralis (VL) were related to (and predictive of) sprinting speed and unilateral (and bilateral) force (FRC) and power (POW) during a 30 s maximal sprint on the Woodway Curve 3.0TM non-motorized treadmill (TM). Twenty-eight healthy, physically active men (n = 14) and women (n = 14) (age = 22.9 ± 2.4 years; body mass = 77.1 ± 16.2 kg; height = 171.6 ± 11.2 cm; body-fa t = 19.4 ± 8.1%) completed one familiarization and one 30-s maximal sprint on the TM to obtain maximal sprinting speed, POW and FRC. Muscle thickness (MT), cross-sectional area (CSA) and echo intensity (ECHO) of the RF and VL in the dominant (DOM; determined by unilateral sprinting power) and non-dominant (ND) legs were measured via ultrasound. Pearson correlations indicated several significant (p < 0.05) relationships between sprinting performance [POW (peak, DOM and ND), FRC (peak, DOM, ND) and sprinting time] and muscle architecture. Stepwise regression indicated that POWDOM was predictive of ipsilateral RF (MT and CSA) and VL (CSA and ECHO), while POWND was predictive of ipsilateral RF (MT and CSA) and VL (CSA); sprinting power/force asymmetry was not predictive of architecture asymmetry. Sprinting time was best predicted by peak power and peak force, though muscle quality (ECHO) and the bilateral percent difference in VL (CSA) were strong architectural predictors. Muscle architecture is related to (and predictive of) TM sprinting performance, while unilateral POW is predictive of ipsilateral architecture. However, the extent to which architecture and other factors (i.e. neuromuscular control and sprinting technique) affect TM performance remains unknown.  相似文献   

16.
PurposeThe purposes of the present study were: (1) to determine whether the physical working capacity at the fatigue threshold (PWCFT) model that has been used for estimating the onset of neuromuscular fatigue in the vastus lateralis (VL) during incremental treadmill running could also be applied to the vastus medialis (VM), biceps femoris (BF), and semitendinosus (ST) muscles; and (2) if applicable, to compare the running velocities associated with the PWCFT among these muscles.MethodsEleven subjects (age 21.7 ± 1.8 years) performed an incremental treadmill test to exhaustion with electromyographic signals recorded from the VL, VM, BF, and ST.ResultsThe results indicated there were no significant (p > 0.05) mean differences in the running velocities associated with the PWCFT for the VL (14.4 ± 2.0 km/h), VM (14.3 ± 1.9 km/h), BF (13.8 ± 1.8 km/h), and ST (14.7 ± 2.3 km/h). In addition, there were significant inter-correlations (r = 0.68–0.88) among running velocities associated with the PWCFT of each muscle. Individual results also indicated that 9 of the 11 subjects exhibited identical PWCFT values for at least 3 of the 4 muscles, but there were no uniform patterns for any intra-individual differences.ConclusionThe findings of the present study suggested that the PWCFT test is a viable method to identify neuromuscular fatigue in the quadriceps and hamstrings during incremental treadmill exercise and results in consistent PWCFT values among these muscles.  相似文献   

17.
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   

18.
A popular method to improve athletic performance and lower body power is to train with wearable resistance (WR), for example, weighted vests. However, it is currently unknown what training effect this loading method has on full-body explosive movements such as the power clean. The purpose of this study was to determine what effects WR equivalent to 12% body mass (BM) had on the power clean and countermovement jump (CMJ) performance. Sixteen male subjects (age: 23.2?±?2.7 years; BM: 90.5?±?10.3?kg) were randomly assigned to five weeks of traditional (TR) power clean training or training with 12% BM redistributed from the bar to the body using WR. Variables of interest included pre and post CMJ height, power clean one repetition maximum (1RM), peak ground reaction force, power output (PO), and several bar path kinematic variables across loads at 50%, 70%, and 90% of 1RM. The main findings were that WR training: (1) increased CMJ height (8.7%; ES?=?0.53) and 1RM power clean (4.2%; ES?=?0.2) as compared to the TR group (CMJ height?=??1.4%; 1RM power clean?=?1.8%); (2) increased PO across all 1RM loads (ES?=?0.33–0.62); (3) increased barbell velocity at 90% 1RM (3.5%; ES?=?0.74) as compared to the TR group (?4.3%); and (4) several bar path kinematic variables improved at 70% and 90% 1RM loads. WR power clean training with 12% BM can positively influence power clean ability and CMJ performance, as well as improve technique factors.  相似文献   

19.
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   

20.
The purpose of this study was to examine the influence of a carbohydrate-rich meal on post-prandial metabolic responses and skeletal muscle glycogen concentration. After an overnight fast, eight male recreational/club endurance runners ingested a carbohydrate (CHO) meal (2.5 g CHO?·?kg?1 body mass) and biopsies were obtained from the vastus lateralis muscle before and 3 h after the meal. Ingestion of the meal resulted in a 10.6?±?2.5% (P?<?0.05) increase in muscle glycogen concentration (pre-meal vs post-meal: 314.0?±?33.9 vs 347.3?±?31.3 mmol?·?kg?1 dry weight). Three hours after ingestion, mean serum insulin concentrations had not returned to pre-feeding values (0 min vs 180 min: 45?±?4 vs 143?±?21 pmol?·?l?1). On a separate occasion, six similar individuals ingested the meal or fasted for a further 3 h during which time expired air samples were collected to estimate the amount of carbohydrate oxidized over the 3 h post-prandial period. It was estimated that about 20% of the carbohydrate consumed was converted into muscle glycogen, and about 12 % was oxidized. We conclude that a meal providing 2.5 g CHO?·?kg?1 body mass can increase muscle glycogen stores 3 h after ingestion. However, an estimated 67% of the carbohydrate ingested was unaccounted for and this may have been stored as liver glycogen and/or still be in the gastrointestinal tract.  相似文献   

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