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1.
Abstract

The aim of this study was to assess and compare the validity of the portable VmaxST telemetry metabolic measurement device with that of a standard measurement system (Vmax29). Thirty asymptomatic, moderately active males provided written, informed consent and completed two maximal graded treadmill exercise tests (Bruce) using the VmaxST and the Vmax29 metabolic measurement systems. Tests were performed in random order on separate days to obtain peak values for time to exhaustion, heart rate, systolic and diastolic blood pressure, oxygen consumption ([Vdot]O2), carbon dioxide production ([Vdot]CO2), ventilation ([Vdot] E), and respiratory exchange ratio (RER). Multivariate analysis of variance revealed no significant main effect (P = 0.88) between the two systems across any variable, suggesting similar measurement capabilities between the two systems. Linear regression analyses revealed moderate to high coefficients of determination for [Vdot]O2 (r 2 = 0.99), [Vdot]CO2 (r 2 = 0.99), [Vdot] E (r 2 = 0.99), and RER (r 2 = 0.89). Furthermore, Bland-Altman analyses demonstrated that the VmaxST yielded similar values to the Vmax29, suggesting good agreement between the two systems. Agreement was confirmed when the differences between the methods resulted in a small range as identified by the 95% limits of agreement. Findings from the current study confirm that the VmaxST is a valid device for measuring metabolic and physiological variables during exercise within a controlled laboratory setting.  相似文献   

2.
现代社会生活方式的改变，给人类健康带来极大的威胁。通过增加日常体力活动量（约占总能量消耗量的20%），可以有效减少和控制慢性非传染性疾病的发生和发展，减轻社会医疗负担。便携式遥测气体代谢仪可测量自由状态下的体力活动量，因而被广泛应用于智能手机、可穿戴和虚拟现实设备的开发和应用，以及竞技体育科研等健康促进领域的研究，目前对便携式遥测气体代谢仪准确的使用范围知之不深。本文对常见的几种便携式遥测气体代谢仪（包括：Cosmed K4b2、Metamax 3B/VmaxST、Oxycon Mobile、VO2000）在不同环境、不同条件下测量的信度和效度及其核心指标VO2、VCO2和VE进行分析，以期为相关的研究和应用提供参考。  相似文献   

3.
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   

4.
Kinetics of heart rate responses to exercise   总被引：4，自引：0，他引：4  
In order to describe the kinetics of the reaction of the heart rate (HR) to the onset of exercise of constant intensity, the half-time (t1/2) of HR can be used. First in a study of exercise of intensity corresponding to 2 W kg-1 on a cycle ergometer, the t1/2 in 15 trained male rowers and 11 untrained male students was determined. In the trained subjects t1/2 was smaller than in untrained students, mean (+/- S.D.) values being 24.10 (+/- 3.36) s and 47.12 (+/- 4.08) s respectively. In both groups t1/2 was positively correlated with resting HR, r = 0.774 and 0.846 and negatively correlated with maximal oxygen uptake (VO2max), r = -0.728 and -0.871 respectively (P less than 0.01). The regulation of HR in the transition range was concluded to be very similar to the regulation of VO2 and energy requirements. The second part of this work was concerned with responses to graded exercise. The linearity of the HR-exercise intensity relationship is maintained up to a submaximal exercise intensity beyond which the increase in exercise intensity exceeds the increase in HR. It was hypothesized that the point where HR departs from linearity in an incremental exercise test may be employed as a predictor of the ventilatory threshold (Tvent). To examine this, 28 trained male long-distance runners were tested on a treadmill and 17 untrained young male subjects were tested on a cycle ergometer using a continuous incremental protocol. The Tvent was determined from the dependence of VE on VO2 and/or VCO2. The VO2, HR and exercise intensity at Tvent were compared with the same parameters determined from the dependence of HR on exercise intensity. No significant differences were found between Tvent and HR break point levels. It was concluded from this second study that the HR break point level coincides with Tvent.  相似文献   

5.
This study examined whether the ventilatory (V) compensation for metabolic acidosis with increasing O2 uptake (VO2) and CO2 output (VCO2) might be more in accord with the theoretical expectation of a progressive acceleration of proton production from carbohydrate oxidation rather than a sudden onset of blood lactate (BLa) accumulation. The interrelationships between V, VO2, VCO2 and BLa concentration, [BLa], were investigated in 10 endurance-trained male cyclists during incremental (120 +/- 15 W min-1) exercise tests to exhaustion. Regression analyses on the V, VCO2 and [BLa] vs VO2 data revealed that all were better fitted by continuous Y = A.exp.[B.VO2] + C rate laws than by threshold linear rate equations (P < 0.0001). Plots of V vs VCO2 and [BLa] were also non-linear. Ventilation increased as an exponential V = 27 +/- 4.exp.[0.37 +/- 0.03.VCO2] function of VCO2 and as a hyperbolic function of [BLa]. In opposition to the 'anaerobic (lactate) threshold' hypothesis, we suggest these data are more readily explained by a continuous development of acidosis, rather than a sudden onset of BLa accumulation, during progressive exercise.  相似文献   

6.
In this study, we assessed the performance of trained senior (n = 6) and veteran (n = 6) cyclists (mean age 28 years, s = 3 and 57 years, s = 4 respectively). Each competitor completed two cycling tests, a ramped peak aerobic test and an indoor 16.1-km time-trial. The tests were performed using a Kingcycle ergometer with the cyclists riding their own bicycle fitted with an SRM powermeter. Power output, heart rate, and gas exchange variables were recorded continuously and blood lactate concentration [HLa] was assessed 3 min after the peak ramped test and at 2.5-min intervals during the time-trial. Peak values for power output (RMP(max)), heart rate (HR(peak)), oxygen uptake (VO2(peak)), and ventilation (V(Epeak)) attained during the ramped test were higher in the senior group (P < 0.05), whereas [HLa](peak), RER(peak), V(E): VO2(peak), and economy(peak) were similar between groups (P > 0.05). Time-trial values (mean for duration of race) for power output (W(TT)), heart rate (HR(TT)), VO2 (VO(2TT)), and V(E) (V(ETT)) were higher in the seniors (P < 0.05), but [HLa](TT), RER(TT), V(ETT): VO2(TT), and economy(TT) were similar between the groups (P > 0.05). Time-trial exercise intensity, expressed as %RMP(max), %HR(peak), % VO2(peak), and % V(Epeak), was similar (P > 0.05) for seniors and veterans (W(TT): 81%, s = 2 vs. 78%, s = 8; HR(TT): 96%, s = 4 vs. 94%, s = 4; VO2(TT): 92%, s = 4 vs. 95%, s = 10; V(ETT): 89%, s = 8 vs. 85%, s = 8, respectively). Overall, seniors attained higher absolute values for power output, heart rate, VO2, and V(E) but not blood lactate concentration, respiratory exchange ratio (RER), V(E): VO2, and economy. Veterans did not accommodate age-related declines in time trial performance by maintaining higher relative exercise intensity.  相似文献   

7.
Repeated bouts of sprint running after induced alkalosis.   总被引：1，自引：0，他引：1  
Seven healthy male subjects performed 10 maximal 6-s sprints, separated by 30-s recovery periods, on a non-motorized treadmill. On two occasions, separated by 3 days, the subjects ingested a solution of either sodium bicarbonate (NaHCO3; alkaline) or sodium chloride (NaCl; placebo), 2.5 h prior to exercise. The doses were 0.3 g kg-1 body mass for the alkaline treatment and 1.5 g total for the placebo, dissolved in 500 ml of water. The order of testing was randomly assigned. Pre-exercise blood pH was 7.43 +/- 0.02 and 7.38 +/- 0.01 for the alkaline and placebo trials respectively (P less than 0.01). Performance indices (i.e. mean and peak power outputs and mean and peak running speeds) were significantly reduced as a result of the cumulative effects of successive sprints, but not significantly affected by the treatments. However, the total work done (i.e. mean power output) in the alkaline condition was 2% higher than that achieved in the placebo condition. Post-exercise blood lactate concentrations were higher for the alkaline treatment than for the placebo condition (15.3 +/- 3.7 vs 13.6 +/- 3.0 mM respectively; P less than 0.01), but blood pH was similar in both conditions (alkaline: 7.15 +/- 0.13; placebo: 7.09 +/- 0.11). In both conditions, a relationship was found between post-exercise blood lactate and mean power output (alkaline: r = 0.82, P less than 0.01; placebo: r = 0.79, P less than 0.01). No significant differences were found in VE, VO2 and VCO2 between the two experimental conditions. This study demonstrates that alkali ingestion results in significant shifts in the acid-base balance of the blood, but has no effect on the power output during repeated bouts of brief maximal exercise.  相似文献   

8.
Maximal oxygen uptake VO(2max)) is considered the optimal method to assess aerobic fitness. The measurement of VO(2max), however, requires special equipment and training. Maximal exercise testing with determination of maximal power output offers a more simple approach. This study explores the relationship between [Vdot]O(2max) and maximal power output in 247 children (139 boys and 108 girls) aged 7.9-11.1 years. Maximal oxygen uptake was measured by indirect calorimetry during a maximal ergometer exercise test with an initial workload of 30 W and 15 W x min(-1) increments. Maximal power output was also measured. A sample (n = 124) was used to calculate reference equations, which were then validated using another sample (n = 123). The linear reference equation for both sexes combined was: VO(2max) (ml x min(-1)) = 96 + 10.6 x maximal power + 3.5 . body mass. Using this reference equation, estimated VO(2max) per unit of body mass (ml x min(-1) x kg(-1)) calculated from maximal power correlated closely with the direct measurement of VO(2max) (r = 0.91, P <0.001). Bland-Altman analysis gave a mean limits of agreement of 0.2+/-2.9 (ml x min(-1) x kg(-1)) (1 s). Our results suggest that maximal power output serves as a good surrogate measurement for VO(2max) in population studies of children aged 8-11 years.  相似文献   

9.
The purpose of the study was to relate three determinants of distance running success, (a) maximal oxygen consumption (VO2max), (b) ventilatory threshold (VT), and (c) running economy (RE), to actual running time in a 5-km race (ART). Twenty-four female runners (M age = 15.9 years) from four high school teams that competed at the Massachusetts All-State 5-km Cross Country Championship Meet and placed 1st, 7th, 19th, and 20th were tested in the laboratory. The mean VO2max of these runners was 61.7 ml.kg-1.min-1, HRmax 201 b.min-1, VEmax 100 L.min-1, and RER 1.10. The VT occurred at 79% of the VO2max, and HR of 184 b.min-1 (92% of HRmax). The velocity at VT (vVT) and velocity at VO2max (vVO2max) was correlated with ART, r(22) = .78 and .77 (p less than .001), respectively. The VO2 at VT and at maximal exercise was correlated with ART by r(22) = -.66 and -.69 (p less than .001), respectively. The VO2 at 215 m.min-1 (8 mph) was poorly related to ART, r(22) = -.05, p greater than .05. It was concluded that either of the derived variables vVT and vVO2max appear to explain significant variation in distance running performance among adolescent female cross country runners.  相似文献   

10.
短期高强度训练对优秀篮球运动员有氧耐力的影响   总被引：7，自引：1，他引：6  
马冀平 《体育学刊》2002,9(1):40-41
为了调查短期高强度训练对篮球运动员有氧耐力的影响 ,对 2 0名 (男、女各 10名 )优秀篮球运动员 ,进行跑台渐增负荷运动直到力竭为止。同时测定气体代谢最大吸氧量 (VO2max)、通气量 (VE)、血乳酸(BLa)、心率 (HR)、血睾酮 (T)、皮质醇 (Cor)及血红蛋白 (Hb)。结果为 :1)短期高强度训练期后男、女两组无氧阈 (AT)值与训练前相比较均有显著性差异 (P <0 .0 5 ) ,但VO2max却未有显著性差异 ;2 )短期高强度训练期后男、女两组Hb值与训练前相比较均有显著性差异 (P <0 .0 5 ) ,而T、Cor在训练期前后却未有显著性差异。其结果表明 ,短期高强度训练并不能提高VO2max,而AT却明显提高。提示可采用AT值作为反映篮球运动员有氧耐力的指标。  相似文献   

11.
The purpose of this study was to assess the validity of predicting the maximal oxygen uptake (VO2(max)) of sedentary men from sub-maximal VO2 values obtained during a perceptually regulated exercise test. Thirteen healthy, sedentary males aged 29-52 years completed five graded exercise tests on a cycle ergometer. The first and fifth test involved a graded exercise test to determine VO2(max). The two maximal graded exercise tests were separated by three sub-maximal graded exercise tests, perceptually regulated at 3-min RPE intensities of 9, 11, 13, 15, and 17 on the Borg ratings of perceived exertion (RPE) scale, in that order. After confirmation that individual linear regression models provided the most appropriate fit to the data, the regression lines for the perceptual ranges 9-17, 9-15, and 11-17 were extrapolated to RPE 20 to predict VO2(max). There were no significant differences between VO2(max) values from the graded exercise tests (mean 43.9 ml x kg(-1) x min(-1), s = 6.3) and predicted VO2(max) values for the perceptual ranges 9-17 (40.7 ml x kg(-1) x min(-1), s = 2.2) and RPE 11-17 (42.5 ml x kg(-1) x min(-1), s = 2.3) across the three trials. The predicted VO2(max) from the perceptual range 9-15 was significantly lower (P < 0.05) (37.7 ml x kg(-1) x min(-1), s = 2.3). The intra-class correlation coefficients between actual and predicted VO2(max) for RPE 9-17 and RPE 11-17 across trials ranged from 0.80 to 0.87. Limits of agreement analysis on actual and predicted VO2 values (bias +/- 1.96 x S(diff)) were 3.4 ml x kg(-1) x min(-1) (+/- 10.7), 2.4 ml x kg(-1) x min(-1) (+/- 9.9), and 3.7 ml x kg(-1) x min(-1) (+/- 12.8) (trials 1, 2, and 3, respectively) of RPE range 9-17. Results suggest that a sub-maximal, perceptually guided graded exercise test provides acceptable estimates of VO2(max) in young to middle-aged sedentary males.  相似文献   

12.
Maximum oxygen uptake (VO(2PEAK)) is generally considered to be the best single marker for aerobic fitness. While a positive relationship between daily physical activity and aerobic fitness has been established in adults, the relationship appears less clear in children and adolescents. The purpose of this paper is to summarise recently published data on the relationship between daily physical activity, as measured by accelerometers, and VO(2PEAK) in children and adolescents. A PubMed search was performed on 29 October 2010 to identify relevant articles. Studies were considered relevant if they included measurement of daily physical activity by accelerometry and related to a VO(2PEAK) either measured directly at a maximal exercise test or estimated from maximal power output. A total of nine studies were identified, with a total number of 6116 children and adolescents investigated. Most studies reported a low-to-moderate relationship (r = 0.10-0.45) between objectively measured daily physical activity and VO(2PEAK). No conclusive evidence exists that physical activity of higher intensities are more closely related to VO(2PEAK), than lower intensities.  相似文献   

13.
Effect of a carbohydrate mouthwash on running time-trial performance   总被引：1，自引：0，他引：1  
The aim of the present study was to determine the effect of a carbohydrate mouthwash on running time-trial performance. On two separate occasions, seven recreationally active males (VO2max 57.8 ml x kg(-1) x min(-1), s = 3.7) completed a preloaded (15 min at 65%VO2max) time-trial of 45 min in duration on a motorized treadmill. At 6-min intervals during the preload and time-trial, participants were given either a 6% maltodextrin, 3% lemon juice solution (carbohydrate trial) or a 3% lemon juice placebo mouthwash (placebo trial) in a double-blind, randomized crossover design. Heart rate, oxygen consumption (VO2), respiratory exchange ratio (RER), and ratings of perceived exertion (RPE) were measured during the preload, and blood glucose and lactate were measured before and after the preload and time-trial. There were no significant differences in distance covered between trials (carbohydrate: 9333 m, s = 988; placebo: 9309 m, s = 993). Furthermore, there were no significant between-trial differences in heart rate and running speed during the time-trial, or VO2, RER or RPE during the preload. Blood lactate and glucose increased as a result of the exercise protocol, with no between-trial differences. In conclusion, there was no positive effect of a carbohydrate mouthwash on running performance of approximately 1 h duration.  相似文献   

14.
Determinants of success during triathlon competition   总被引：1，自引：0，他引：1  
Eleven male triathletes were studied to determine the relationships between selected metabolic measurements and triathlon performance. Measurements of oxygen uptake (VO2), pulmonary ventilation (VE), and heart rate (HR) were made during submaximal and maximal 365.8 m freestyle swimming (FS), cycle ergometry (CE), and treadmill running (TR). Submaximal workloads were 1 m/s for swimming, 200 W for cycling, and 201.2 m/min for running. The mean VO2 max (l/min) was significantly (p less than .05) lower during FS (4.17) than CE (4.68) or TR (4.81). Swimming, cycling, and running performance times during the Muncie Endurathon (1.2 mile swim, 56 mile cycle, 13.1 mile run) were not significantly related to the event-specific VO2 max (ml/kg/min): -.49, -32 and -.55, respectively. The VO2 max expressed in l/min was found to be significantly (p less than .05) related to cycling time (r = -.70). A significant (p less than .05) relationship was observed between submaximal VO2 (ml/kg/min) during TM and run performance time (r = .64), whereas swimming and cycling performance times were significantly (p less than .05) related to submaximal VO2 max (l/min), r = .72 and .60, respectively. The percentage of VO2 (%VO2 max) used during the submaximal tests was significantly (p less than .05) related to swimming (.91), cycling (.78), and running (.86) performance times. Time spent running and cycling during triathlon competition was significantly (p less than .05) related to overall triathlon time, r = .97 and .81, respectively. However, swimming time was not significantly related (.30) to overall triathlon time. This study suggests that economy of effort is an important determinant of triathlon performance.  相似文献   

15.
The purpose of the present study was to determine the effects of 10-in [0.25-m] versus 16-in [0.41-m] wheelchair handrims on cardiorespiratory and psychophysiological exercise responses during wheelchair propulsion at selected velocities. Fifteen male paraplegics (27.0 +/- 5.5 yrs) performed three discontinuous exercise tests (ACE = arm crank ergometer; WERG = wheelchair roller ergometer) and two 1600-m performance-based track trials (TRACK) under simulated race conditions. There were no significant differences in HR, VO2, VE, HLa, or category-ratio ratings of perceived exertion (RPE) using different handrims during wheelchair propulsion at 4 km.h-1. In contrast, at 8 km.h-1 subjects demonstrated a 13% lower steady state VO2 (p less than .05) using the 10-in handrims, coincident with a 23% lower VE. Steady state HR during WERG at 8 km.h-1 using the 10-in (124.4 +/- 3.9 b.min-1) or 16-in (130.6 +/- 4.6 b.min-1) handrims were not significantly different. There were also no significant differences between ACE or WERG conditions during maximal effort for VO2 or VE. However, HRpeak during ACE was 7% higher than HRpeak during WERG16 (183 +/- 15 b.min-1 vs. 171 +/- 12 b.min-1, p less than .05), and whole blood HLa during ACE was also significantly higher (by 2.3-2.5 mmol; p less than .05) compared to WERG. There were no significant differences for HR, performance time, or RPE between trials using different handrim diameters during the 1600-m event.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

16.
The aim of this study was to determine the effects of frequency of verbal encouragement during maximal exercise testing. Twenty-eight participants (12 males, 16 females) aged 20.9 +/- 1.5 years (mean +/- s) performed a maximal exercise test (VO2max) on a treadmill without any verbal encouragement. The participants were matched according to their pre-test VO2max and placed into either a control group or one of three experimental groups. They performed a second exercise test (post-test) 1 week later. During the second test, the control group received no verbal encouragement; the 20 s (20E), 60 s (60E) and 180 s (180E) encouragement groups received verbal encouragement every 20, 60 and 180 s, respectively, beginning with stage 3 of the exercise test. Relative VO2max, exercise time, blood lactate concentration, respiratory exchange ratio (RER) and ratings of perceived exertion (RPE) were not significantly different from the first test to the second test for the control group without verbal encouragement and the 180E group that received infrequent encouragement. Post-test values were significantly higher than pre-test values for the 20E and 60E groups. The post-test values of the 20E group were significantly higher than their pre-test values for relative VO2max (P < 0.001), exercise time (P < 0.0001), blood lactate concentration (P < 0.05), RER (P < 0.01) and RPE (P < 0.0001); this was also the case for the 60E group for relative VO2max (P < 0.01), blood lactate concentration (P < 0.05), RER (P < 0.05) and RPE (P < 0.05). The results suggest that frequent verbal encouragement (every 20 s and 60 s in the present study) leads to significantly greater maximum effort in a treadmill test than when no encouragement is given or when the encouragement is infrequent (i.e. every 180 s).  相似文献   

17.
In this study, we evaluated the effects of a novel pedal design, characterized by a downward and forward shift of the cleat fixing platform relative to the pedal axle, on maximal power output and mechanical efficiency in 22 well-trained cyclists. Maximal power output was measured during a series of short (5-s) intermittent sprints on an isokinetic cycle ergometer at cadences from 40 to 120 rev min(-1). Mechanical efficiency was evaluated during a submaximal incremental exercise test on a bicycle ergometer using continuous VO(2) and VCO(2) measurement. Similar tests with conventional pedals and the novel pedals, which were mounted on the individual racing bike of the participant, were randomized. Maximal power was greater with novel pedals than with conventional pedals (between 6.0%, s(x) = 1.5 at 40 rev min(-1) and 1.8%, s(x) = 0.7 at 120 rev min(-1); P = 0.01). Torque production between crank angles of 60 degrees and 150 degrees was higher with novel pedals than with conventional pedals (P = 0.004). The novel pedal design did not affect whole-body VO(2) or VCO(2). Mechanical efficiency was greater with novel pedals than with conventional pedals (27.2%, s(x) = 0.9 and 25.1%, s(x) = 0.9% respectively; P = 0.047; effect size = 0.9). In conclusion, the novel pedals can increase maximal power output and mechanical efficiency in well-trained cyclists.  相似文献   

18.
The purpose of the present study was to assess fitness and running performance in a group of recreational runners (men, n = 18; women, n = 13). 'Fitness' was determined on the basis of their physiological and metabolic responses during maximal and submaximal exercise. There were strong correlations between VO2 max and treadmill running speeds equivalent to blood lactate concentrations of 2 mmol l-1 (V-2 mM) or 4 mmol l-1 (V-4 mM), 'relative running economy' and 5 km times (r = -0.84), but modest and non-significant correlations between muscle fibre composition and running performance. The results of the submaximal exercise tests suggested that the female runners were as well trained as the male runners. However, the men still recorded faster 5 km times (19.20 +/- 1.97 min vs 20.97 +/- 1.70 min; P less than 0.05). Therefore the of the present study suggest that the faster performance times recorded by the men were best explained by their higher VO2 max values, rather than their training status per se.  相似文献   

19.
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   

20.
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 strides.min-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 ml.kg-1 per stride and 0.7 ml.kg-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   

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