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1.
In the current study, we examined the relationship between serum creatine kinase (CK) activity following upper body resistance exercise with a 1- or 3-min rest between sets. Twenty men performed two sessions, each consisting of four sets with a 10-repetition maximum load. The results demonstrated significantly greater volume for the 3-min condition (M = 4156 kg, SD = 867, for 3 min; vs. M = 3503 kg SD = 759, for 1 min; p < .001), with no significant differences in delta CK activity between conditions (p = .574). Nevertheless, there was a weak correlation between the delta CK activity and total volume of exercise completed (r = .55 with a 1-min rest, and r = .45 with a 3-min rest). Therefore, the volume following upper body resistance exercise correlates weakly with serum CK levels, irrespective of rest interval length between sets.  相似文献   

2.
Abstract

This study was designed to examine the magnitude and duration of excess postexercise oxygen consumption (EPOC) following upper body exercise, using lower body exercise for comparison. On separate days and in a counterbalanced order, eight subjects (four male and four female) performed a 20-min exercise at 60% of mode-specific peak oxygen uptake (VO2) using an arm crank and cycle ergometer. Prior to each exercise, baseline VO2 and heart rate (HR) were measured during the final 15 min of a 45-min seated rest. VO2 and HR were measured continuously during the postexercise period until baseline VO2 was reestablished. No significant difference between the two experimental conditions was found for magnitude of EPOC (t [7] = 0.69, p > .05). Mean (± SD) values were 9.2 ± 3.3 and 10.4 ± 5.8 kcal for the arm crank and cycle ergometer exercises, respectively. Duration of EPOC was relatively short and not significantly different (t [7] = 0.24, p > .05) between the upper body (22.9 ± 13.7 min) and lower body (24.2 ± 19.4 min) exercises. Within the framework of the chosen exercise conditions, these results suggest EPOC may be related primarily to the relative metabolic rate of the active musculature, as opposed to the absolute exercise VO2 or quantity of active muscle mass associated with these two types of exercise.  相似文献   

3.
Oxygen uptake (VO2) during treadmill exercise is directly related to the speed and grade, as well as the participant's body weight. To determine whether body composition also affects VO2 (ml.kg-1.min-1) during exercise, we studied 14 male body builders (M weight = 99 kg, SD = 7; M height = 180 cm, SD = 8; M body fat = 8%, SD = 3; M fat free mass = 91 kg, SD = 7) and 14 weight-matched men (M weight = 99 kg, SD = 9; M height = 179 cm, SD = 5; M body fat = 24%, SD = 5; M fat free mass = 73 kg, SD = 9). Percentage of body fat, t(13) = 8.185, p < .0001, and fat free mass, t(13) = 5.723, p < .0001, were significantly different between groups. VO2 was measured by respiratory gas analysis at rest and during three different submaximal workrates while walking on the treadmill without using the handrails for support. VO2 was significantly greater for the lean, highly muscular men at rest: 5.6 +/- 1 vs. 4.0 +/- 1 ml.kg-1.min-1, F(1, 26) = 21.185, p < .001; Stage 1: 1.7 mph/10%, 18.5 +/- 2 vs. 16.1 +/- 2 ml.kg-1.min-1, F(1, 26) = 6.002, p < .05; Stage 2: 2.5 mph/12%, 26.6 +/- 3 vs. 23.1 +/- 2 ml.kg-1.min-1, F(1, 26) = 7.991, p < .01; and Stage 3:3.4 mph/14%, 39.3 +/- 5 vs. 33.5 +/- 5 ml.kg-1.min-1, F(1, 26) = 7.682, p < .01, body builders versus weight-matched men, respectively. However, net VO2 (i.e., exercise VO2 - rest VO2) was not significantly different between the two groups at any of the matched exercise stages. The findings from this study indicate that VO2 during weight-bearing exercise performed at the same submaximal workrate is higher for male body builders compared to that measured in weight-matched men and that which is predicted by standard equations. These observed differences in exercise VO2 appear to be due to the higher resting VO2 in highly muscular participants.  相似文献   

4.
Abstract

In order to examine the effects of different recoveries from high intensity short duration exercise on lactate removal and subsequent performance, 11 subjects completed 8 experimental sessions. Each subject completed an initial all-out pedaling task against 5.5 kg resistance (Monark bicycle ergometer) for 1 min followed by a randomly assigned recovery pattern and a repeat of the all-out exercise task. The main effects examined were active (1.0 kg, 60 rpm) vs passive recovery, inhalation of inhalation of oxygen vs room air during recovery, and 10- vs-20-min duration of recovery. Pedal revolutions were analyzed on a 6- by 6-sec and on a cumulative basis. Blood lactate concentrations were determined during rest, the 3rd–4th, 9th–10th, and 19th–20th min of recovery. Results revealed significant main effects for active vs passive recovery and for 10- vs 20-min recovery, with active and 20-min recovery resulting in significantly higher postrecovery pedal revolutions (p < .001) and enhanced rates of lactate removal during recovery (p < .001). Oxygen inhalation during recovery had no effect on postrecovery performance or lactate removal (p > .05). The correlation between blood lactate levels at the end of recovery and pedal revolutions on the postrecovery exercise task was only r = -.19, suggesting that factors other than lactate removal are critical for subsequent performance.  相似文献   

5.
Myokines may play a role in the health benefits of regular physical activity. Secreted protein acidic rich in cysteine (SPARC) is a pleiotropic myokine that has been shown to be released into the bloodstream by skeletal muscle in response to aerobic exercise. As there is evidence suggesting that SPARC release may be linked to glycogen breakdown and activation of 5’ adenosine monophosphate-activated protein kinase, we hypothesised that brief supramaximal exercise may also be associated with increased serum SPARC levels. In the present study, 10 participants (3 women; mean?±?SD age: 21?±?3 y, body mass index (BMI): 22?±?3?kg?m?2, and V˙O2max: 39?±?6?mL?kg?1?min?1) performed an acute bout of supramaximal cycle exercise (20-s Wingate sprint against 7.5% of body mass, with a 1-min warm-up and a 3-min cool-down consisting of unloaded cycling). Serum SPARC levels were determined pre-exercise as well as 0, 15, and 60?min post-exercise and corrected for plasma volume change. To determine whether regular exercise affected the acute SPARC response, participants repeated the acute exercise protocol three times per week for four weeks, and serum SPARC response to supramaximal exercise was reassessed after this period. Acute supramaximal exercise significantly decreased plasma volume (?10%; p?<?.001), but was not associated with a significant change in serum SPARC levels at either the pre-training or post-training testing sessions. In conclusion, in contrast to aerobic exercise, a single brief supramaximal cycle sprint is not associated with an increase in serum SPARC levels, suggesting that SPARC release is not related to skeletal muscle glycogen breakdown.  相似文献   

6.
This study was designed to examine the magnitude and duration of excess postexercise oxygen consumption (EPOC) following upper body exercise, using lower body exercise for comparison. On separate days and in a counterbalanced order, eight subjects (four male and four female) performed a 20-min exercise at 60% of mode-specific peak oxygen uptake (VO2) using an arm crank and cycle ergometer. Prior to each exercise, baseline VO2 and heart rate (HR) were measured during the final 15 min of a 45-min seated rest. VO2 and HR were measured continuously during the postexercise period until baseline VO2 was reestablished. No significant difference between the two experimental conditions was found for magnitude of EPOC (t [7] = 0.69, p greater than .05). Mean (+/- SD) values were 9.2 +/- 3.3 and 10.4 +/- 5.8 kcal for the arm crank and cycle ergometer exercises, respectively. Duration of EPOC was relatively short and not significantly different (t [7] = 0.24, p greater than .05) between the upper body (22.9 +/- 13.7 min) and lower body (24.2 +/- 19.4 min) exercises. Within the framework of the chosen exercise conditions, these results suggest EPOC may be related primarily to the relative metabolic rate of the active musculature, as opposed to the absolute exercise VO2 or quantity of active muscle mass associated with these two types of exercise.  相似文献   

7.
Abstract

The present study compared the changes in markers of muscle damage after bouts of resistance exercise employing the Multiple-sets (MS) and Half-pyramid (HP) training systems. Ten healthy men (26.1±6.3 years), who had been involved in regular resistance training, performed MS and HP bouts, 14 days apart, in a randomised, counter-balanced manner. For the MS bout, participants performed three sets of maximum repetitions at 75%-1RM (i.e. 75% of a One Repetition Maximum) for the three exercises, starting with the bench press, followed by pec deck and decline bench press. For the HP bout, the participants performed three sets of maximum repetitions with 67%-1RM, 74%-1RM and 80%-1RM for the first, second and third sets, respectively, for the same three exercise sequences as the MS bout. The total volume of load lifted was equated between both bouts. Muscle soreness, plasma creatine kinase (CK) activity, myoglobin (Mb) and C-reactive protein (CRP) concentrations were assessed before and for three days after each exercise bout, and the changes over time were compared between MS and HP using two-way repeated measures ANOVA. Muscle soreness developed significantly (P<0.01) after both bouts, but no significant difference was observed between MS and HP. Plasma CK activity and Mb concentration increased significantly (P<0.01) without significant differences between bouts, and CRP concentration did not change significantly after either bout. These results suggest that the muscle damage profile is similar for MS and HP, probably due to the similar total volume of load lifted.  相似文献   

8.
Abstract

The purpose of this study was to determine if static and baltislic stretching would, induce significant amounts of delayed onset muscle soreness (DOMS) and increases in creatine kinase (CK). Twenty males were randomly assigned to a static (STATIC) or ballistic stretching (BALLISTIC) group. All performed three sets of 17 stretches during a 90-min period, the only group difference being that STATIC remained, stationary during each 60-s stretch while BALLISTIC performed, boundng movements. Subjective ratings of DOMS (scale: 1–10) and serum CK levels were assessed before and every 24 hours post stretching, for 5 days. A repeated measures ANOVA revealed a significant main effect due to time (p < .05), with peak soreness occurring at 24 hours after (M = 2.8 ? 1.6). Surprisingly, a group effect (p < .05) demonstrated. that DOMS was significantly greater for STATIC than for BALLISTIC. At 24 hours there was a 62% (p < .05) increase in CK for combined groups. These findings indicate that similar bouts of static and ballistic stretching induce significant increases in DOMS and CK in subjects unaccustomed to such exercise. Furthermore, static stretching induced significantly more DOMS than did ballistic.  相似文献   

9.
Set configuration may affect the recovery pattern of cardiac vagal autonomic and reflex modulation after a resistance exercise, since it is closely associated with intensity and volume and determines the metabolic involvement of the session. We tested the hypothesis that longer set configurations have a higher impact on cardiac autonomic control and baroreflex sensitivity compared with shorter set configurations. We studied the effects of three set configurations with the same components of work on the cardiac autonomic control and baroreflex sensitivity. Seventeen subjects performed one control session and three experimental sessions of a leg-press exercise with the same volume (40 repetitions), resting time (720?s) and intensity (10RM load): (a) 5 sets of 8 repetitions with 3?min of rest between sets (8S), (b) 10 sets of 4 repetitions with 80?s of rest between sets (4S) and (c) 40 sets of 1 repetition with 18.5?s of rest between each repetition (1S). Longer set configurations (8S and 4S) induced greater reductions of the vagal cardiac autonomic control and baroreflex sensitivity (p?≤?.001) compared with a shorter set configuration (1S). Also, 1S had non-significant reductions versus the control session (p?>?.05). These findings suggest that a shorter set configuration can reduce the impact of resistance exercise on the post-exercise cardiac vagal autonomic control and baroreflex sensitivity.  相似文献   

10.
In this study, we examined the effects of different work:rest durations during 20 min intermittent treadmill running and subsequent performance. Nine males (mean age 25.8 years, s = 6.8; body mass 73.9 kg, s = 8.8; stature 1.75 m, s = 0.05; VO(2max) 55.5 ml x kg(-1) x min(-1), s = 5.8) undertook repeated sprints at 120% of the speed at which VO(2max) was attained interspersed with passive recovery. The work:rest ratio was constant (1:1.5) with trials involving either short (6:9 s) or long (24:36 s) work:rest exercise protocols (total exercise time 8 min). Each trial was followed by a performance run to volitional exhaustion at the same running speed. Testing order was randomized and counterbalanced. Heart rate, oxygen consumption, respiratory exchange ratio, and blood glucose were similar between trials (P > 0.05). Blood lactate concentration was greater during the long than the short exercise protocol (P < 0.05), whereas blood pH was lower during the long than the short exercise protocol (7.28, s = 0.11 and 7.30, s = 0.03 at 20 min, respectively; P < 0.05). Perceptions of effort were greater throughout exercise for the long than the short exercise protocol (16.6, s = 1.4 and 15.1, s = 1.6 at 20 min, respectively; P < 0.05) and correlated with blood lactate (r = 0.43) and bicarbonate concentrations (r = 0.59; P < 0.05). Although blood lactate concentration at 20 min was related to performance time (r = - 0.56; P < 0.05), no differences were observed between trials for time to exhaustion (short exercise protocol: 95.8 s, s = 30.0; long exercise protocol: 92.0 s, s = 37.1) or physiological responses at exhaustion (P > 0.05). Our results demonstrate that 20 min of intermittent exercise involving a long work:rest duration elicits greater metabolic and perceptual strain than intermittent exercise undertaken with a short work:rest duration but does not affect subsequent run time to exhaustion.  相似文献   

11.
Abstract

This study examined the effects of aerobic exercise on spontaneous electroencephalographic (EEG) activity. Participants (N = 34) were asked to (a) sit quietly for a 10-min adaptation period, (b) either exercise on a cycle ergometer (n = 18) or watch a videotape (n = 16) for 15 min, and (c) sit quietly for a 10-min recovery period. EEGs were collected during the last 2 min of the adaptation period, the last 2 min of each 5-min stage of the exercise/videotape period, and the last 2 min of the recovery period. EEG power densities were combined across the alpha and beta frequency bands. The results indicated that brain activation increased (i.e., alpha activity decreased and beta activity increased) during the exercise condition and returned, to baseline following exercise. This did not occur in the nonexercise condition. Thus, the results were consistent with the opponent-process theory (Solomon, 1980) in that brain activation increased during exercise.  相似文献   

12.
The aim of present study was to examine the relationships between serum and salivary values of free testosterone, dehydroepiandrosterone, and cortisol before and after a session of resistance exercise. Twenty-eight healthy men (mean age 40 years, s = 4) participated in the present study. Serum and salivary samples were collected at rest and after a multiple-sets resistance exercise protocol, of approximately 25 minutes duration. Concentrations of free testosterone, dehydroepiandrosterone, and cortisol were measured using radioimmunoassay kits. No significant correlation was observed between serum free testosterone and salivary testosterone (r = 0.22 to 0.26, P > 0.05). Serum cortisol was significantly correlated with salivary cortisol before (r = 0.52, P = 0.005) and after (r = 0.62, P = 0.001) the exercise protocol. Serum and salivary concentrations of dehydroepiandrosterone were significantly correlated before (r = 0.68, P < 0.001) and after (r = 0.7, P < 0.001) exercise. The results of the present study suggest that even under exercise conditions, the salivary values of cortisol and dehydroepiandrosterone can reflect the behaviour of these hormones in blood. However, further studies are necessary to verify if salivary testosterone reflects the behaviour of serum free testosterone during resistance exercise.  相似文献   

13.
BackgroundThere is controversial evidence regarding the effect of acute resistance exercise (ARE) on heart rate variability (HRV) parameters, which indicates the activities of the cardiac autonomic nervous system. The aim of this study was to perform a systematic review and meta-analysis of the literature on the effect of ARE on HRV parameters and identify its possible moderating factors.MethodsThe PubMed–Medline, Web of Science, SPORTDiscus, and Cochrane Library databases were searched. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) declaration was followed, and the methodological quality of the studies was evaluated. The level of significance was set at p ≤ 0.05. Twenty-six studies met the inclusion criteria. Main effect analyses between pre- and post-test interventions demonstrated an increase in normalized units low frequency (p < 0.001; standardized mean difference (SMD) = 0.78; 95% confidence interval (95%CI): 0.46?1.11) and low frequency/high frequency ratio (p < 0.001; SMD = 0.82; 95%CI: 0.64?0.99) and a decrease in standard deviation of the normal-to-normal (NN) interval (p < 0.001; SMD = –0.58; 95%CI: –0.85 to –0.30), root mean square of the successive differences (p < 0.001; SMD = –1.01; 95%CI: –1.29 to –0.74), and normalized units high frequency (p < 0.001; SMD: –1.08; 95%CI: –1.43 to –0.73) following ARE in healthy individuals range: 15 ± 1 to 48 ± 2 years; mean ± SD).ResultsThere were differences between the subgroups in the number of sets used in an exercise (p = 0.05) for root mean square of the successive differences, as well as for exercise intensity (p = 0.01) and rest between sets (p = 0.05) for normalized units high frequency. Interestingly, there were differences between the subgroups in training volume for root mean square of the successive differences (p = 0.01), normalized units high frequency (p = 0.003) and normalized units low frequency (p = 0.02).ConclusionOverall, there was a withdrawal of cardiac parasympathetic and activation of cardiac sympathetic modulations following ARE, and these changes were greater with higher training volume ～30 min after ARE in healthy individuals. Furthermore, the number of sets, intensity, and rest between sets affected HRV parameters. However, gender, body mass index, and training status did not influence the changes in HRV parameters as a response to ARE.  相似文献   

14.
血清肌酸激酶与骨骼肌损伤关系的探讨   总被引：17，自引：0，他引：17  
研究目的在于对血清肌酸激酶与骨骼肌损伤之间的关系进行探讨。采用跑台一次性离心运动至力竭的动物模型,48只7周龄雌性大鼠随机分为安静对照组和运动后即刻、1、2、4和7天组,测定血清肌酸激酶活性,同时通过HE染色分析骨骼肌形态学损伤变化。结果显示血清肌酸激酶活性峰值出现在运动后即刻,运动后1天迅速下降。HE染色结果则表明离心运动后骨骼肌损伤呈现延迟性时相特点,在运动后第2天骨骼肌损伤范围达到最大。本实验表明血清肌酸激酶与骨骼肌损伤的变化趋势并不一致,血清肌酸激酶水平不能反映骨骼肌损伤。  相似文献   

15.
This study examined the influence of differing volume load and intensity (%1 repetition maximum[%1RM]) resistance exercise workouts on session rating of perceived exertion (sRPE) countermovement jump (CMJ) performance and endocrine responses. Twelve participants performed a workout comprising four exercises (bench press, back squat, deadlift and prone bench pull) in randomised order as either power (POW); 3 sets × 6 repetitions at 45%1RM × 3 min inter-set rest, strength (ST); 3 sets × 3 repetitions at 90%1RM × 3 min inter-set rest, or hypertrophy (HYP); 3 sets × 10 repetitions at 70%1RM × 1 min inter-set rest in a randomised-crossover design. CMJ performance and endocrine responses were measured immediately pre-, post-, 12, 24, 48 and 72 h post-exercise. POW sRPE (3.0 ± 1.0) was lower than ST (4.5 ± 1.0) (P = 0.01), and both were lower than HYP (8.5 ± 1.0) (P = 0.01). Duration of CMJ decrement was longer (P ≤ 0.05) for HYP (72 h) compared to POW (12 h) and ST (24 h). Testosterone concentration was greater (P ≤ 0.05) immediately post-exercise in HYP compared to POW and ST. In conclusion, less inter-set rest, greater volume load and intensity (%1RM) may increase sRPE, duration of CMJ performance decrement and testosterone responses in resistance exercise.  相似文献   

16.
Abstract

The purpose of this study was to assess the effects of varied rest intervals, following a 5-min warm-up, upon subsequent ratings of perceived exertion, heart rate (HR), and state anxiety during an exercise period. The subjects were 16 male college students, each with predicted [Vdot]O2 max of at least 51 ml/kg/min ( = 54.4) as determined by the Åstrand bicycle test. Each subject was tested under four experimental conditions following a 5-min warm-up on a bicycle ergometer at 75% of HR max. Rest intervals of 1 min, 5 min, 10 min, and no rest preceded a progressively increasing 8-min exercise period on a bicycle ergometer. Ratings of perceived exertion (RPE), heart rate, and state anxiety were obtained at 1,000, 1,200, 1,400, and 1,600 KPM during each of the experimental conditions. An analysis of variance, four by four factorial design with repeated measures on both factors, was used to determine if significant differences existed between the experimental conditions for RPE and HR. An analysis of variance, treatment by subjects design, was used to determine if there were significant differences in state anxiety levels among the experimental conditions. Intraclass correlations revealed that reliability for HR and RPE was extremely high. No significant difference was found among the four experimental conditions for perceived exertion, heart rate, and state anxiety. RPE was found to be a good predictor of physiological strain as indicated by HR.  相似文献   

17.
ObjectiveResearch on methods of improving the affective experience of exercise remains limited, especially for low-active overweight adults. We investigated the effectiveness of a virtual-reality headset and headphones in improving affective responses over conventionally delivered audiovisual stimulation.MethodsLow-active, overweight adults (16 women, 5 men; age: 34.67 ± 9.62 years; body mass index: 28.56 ± 4.95 kg/m²; peak oxygen uptake for men: 29.14 ± 6.56 mL/kg/min, for women: 22.67 ± 4.52 mL/kg/min, mean ± SD) completed 15-min sessions of recumbent cycling at the ventilatory threshold: (a) high immersion (HI, virtual reality headset and headphones), (b) low immersion (LI, television screen and speakers), and (c) Control. During-exercise pleasure and post-exercise enjoyment were self-reported. Oxygenation of the right dorsolateral prefrontal cortex (dlPFC) was assessed with near infrared spectroscopy.ResultsHigher pleasure was reported during HI than during LI and Control (Condition × Time interaction; p < 0.001, ηp2 = 0.43). Participants who reported a preference for low exercise intensity showed higher dlPFC oxygenation during Control, but this difference diminished during LI and HI (Condition × Time × Preference interaction; p = 0.036, ηp2 = 0.10).ConclusionCompared with conventionally delivered audiovisual stimulation, using a virtual-reality headset strengthens the dissociative effect, further improving affective responses to exercise at the ventilatory threshold among overweight, low-active adults. Presumably by competing with interoceptive afferents at the level of sensory input, audiovisual stimulation may lessen reliance on cognitive efforts to attenuate declining affect, as indicated by lower right dlPFC activity, particularly among participants disinclined toward high exercise intensity.  相似文献   

18.
The power output achieved at peak oxygen consumption (VO2peak) and the time this power can be maintained (i.e., Tmax) have been used in prescribing high-intensity interval training. In this context, the present study examined temporal aspects of the VO2 response to exercise at the cycling power that output well trained cyclists achieve their VO2peak (i.e., Pmax). Following a progressive exercise test to determine VO2peak, 43 well trained male cyclists (M age = 25 years, SD = 6; M mass = 75 kg, SD = 7; M VO2peak = 64.8 ml x kg(-1) x min(-1), SD = 5.2) performed two Tmax tests 1 week apart. Values expressed for each participant are means and standard deviations of these two tests. Participants achieved a mean VO2peak during the Tmax test after 176 s (SD = 40; M = 74% of Tmax, SD = 12) and maintained it for 66 s (SD = 39; M = 26% of Tmax, SD = 12). Additionally, they obtained mean 95% of VO2peak after 147 s (SD = 31; M = 62% of Tmax, SD = 8) and maintained it for 95 s (SD = 38; M = 38% of Tmax, SD = 8). These results suggest that 60-70% of Tmax is an appropriate exercise duration for a population of well trained cyclists to attain VO2peak during exercise at Pmax. However, due to intraparticipant variability in the temporal aspects of the VO2 response to exercise at Pmax, future research is needed to examine whether individual high-intensity interval training programs for well trained endurance athletes might best be prescribed according to an athlete's individual VO2 response to exercise at Pmax.  相似文献   

19.
We measured the effects of stride rate, resistance, and combined arm-leg use on energy expenditure during elliptical trainer exercise and assessed the accuracy of the manufacturer's energy expenditure calculations. Twenty-six men and women (M age = 29 years, SD = 8; M body weight = 73. 0 kg, SD = 15.2) participated. Twenty-two participants performed two tests, one without the arm poles (leg-only) and the other with arm poles (combined arm-leg). The other 4 participants performed one test without the arm poles. Both tests consisted of six 5-min stages (two stride rates, 110 and 134 stridesmin-1, and three resistance settings: 2, 5, and 8). Steady-state oxygen uptake (VO2), minute ventilation (VE), heart rate (HR) and rating of perceived exertion (RPE) were measured. Repeated measures analysis of variance determined higher (p <. 001) VO2, VE, and RPE, but not HR, during combined arm-leg versus leg-only exercise at any given intensity. Increases in stride rate and resistance increased VO2, VE, RPE, and HR with the greatest effect on VE and HR from Levels 5 to 8. The manufacturer's calculated energy expenditure was overestimated during both tests. Although the oxygen cost for elliptical trainer exercise was calculated to be approximately 0.1 mlxkg(-1) per stride and 0.7 mlxkg(-1) min-1 per resistance level, VO2 varied widely among individuals, possibly due to differences in experience using the elliptical trainer gender, and body composition. The elliptical trainer offers (a) a variety of intensities appropriate for most individuals and (b) both arm and leg exercise. Due to the wide variability in VO2, predicting the metabolic cost during elliptical trainer exercise for an individual is not appropriate.  相似文献   

20.
Abstract

The effect of altering the rest period on adaptations to high-repetition resistance training is not well known. Eighteen active females were matched according to leg strength and repeated-sprint ability and randomly allocated to one of two groups. One group performed resistance training with 20-s rest intervals between sets, while the other group employed 80-s rest intervals between sets. Both groups performed the same total training volume and load. Each group trained 3 days a week for 5 weeks [15- to 20-repetition maximum (RM), 2 – 5 sets]. Repeated-sprint ability (5×6-s maximal cycle sprints), 3-RM leg press strength, and anthropometry were determined before and after each training programme. There was a greater improvement in repeated-sprint ability after training with 20-s rest intervals (12.5%) than after training with 80-s rest intervals (5.4%) (P = 0.030). In contrast, there were greater improvements in strength after training with 80-s rest intervals (45.9%) than after training with 20-s rest intervals (19.6%) (P = 0.010). There were no changes in anthropometry for either group following training. These results suggest that when training volume and load are matched, despite a smaller increase in strength, 5 weeks of training with short rest periods results in greater improvements in repeated-sprint ability than the same training with long rest periods.  相似文献   

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