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1.
We compared SenseWear Armband versions (v) 2.2 and 5.2 for estimating energy expenditure in healthy adults. Thirty-four adults (26 women), 30.1 ± 8.7 years old, performed two trials that included light-, moderate- and vigorous-intensity activities: (1) structured routine: seven activities performed for 8-min each, with 4-min of rest between activities; (2) semi-structured routine: 12 activities performed for 5-min each, with no rest between activities. Energy expenditure was measured by indirect calorimetry and predicted using SenseWear v2.2 and v5.2. Compared to indirect calorimetry (297.8 ± 54.2 kcal), the total energy expenditure was overestimated (P < 0.05) by both SenseWear v2.2 (355.6 ± 64.3 kcal) and v5.2 (342.6 ± 63.8 kcal) during the structured routine. During the semi-structured routine, the total energy expenditure for SenseWear v5.2 (275.2 ± 63.0 kcal) was not different than indirect calorimetry (262.8 ± 52.9 kcal), and both were lower (P < 0.05) than v2.2 (312.2 ± 74.5 kcal). The average mean absolute per cent error was lower for the SenseWear v5.2 than for v2.2 (P < 0.001). SenseWear v5.2 improved energy expenditure estimation for some activities (sweeping, loading/unloading boxes, walking), but produced larger errors for others (cycling, rowing). Although both algorithms overestimated energy expenditure as well as time spent in moderate-intensity physical activity (P < 0.05), v5.2 offered better estimates than v2.2.  相似文献   

2.
This study compared the energy expenditure (EE) levels during object projection skill performance (OPSP) as assessed by indirect calorimetry and accelerometry. Thirty-four adults (female n = 18) aged 18–30 (23.5 ± 2.5 years) performed three, 9-min sessions of kicking, over-arm throwing, and striking performed at 6-, 12-, and 30-sec intervals. EE was estimated (METS) using indirect calorimetry (COSMED K4b2) and hip-worn accelerometry (ActiGraph GT3X+). EE using indirect calorimetry demonstrated moderate-intensity physical activity (3.4 ± 0.7 METS––30-sec interval, 5.8 ± 1.2 METS––12-sec interval) to vigorous intensity physical activity (8.3 ± 1.7 METS––6-sec interval). However, accelerometry predicted EE suggested only light-intensity physical activity (1.7 ± 0.2 METS––30-sec interval, 2.2 ± 0.4 METS––12-sec interval, 2.7 ± 0.6 METS––6-sec interval). Hip-worn, ActiGraph GT3X+ accelerometers do not adequately capture physical activity intensity levels during OPSP, regardless of differences in skill performance intervals.  相似文献   

3.
The purpose of this investigation was to examine the validity of energy expenditure (EE), steps, and heart rate measured with the Apple Watch 1 and Fitbit Charge HR. Thirty-nine healthy adults wore the two monitors while completing a semi-structured activity protocol consisting of 20 minutes of sedentary activity, 25 minutes of aerobic exercise, and 25 minutes of light intensity physical activity. Criterion measures were obtained from an Oxycon Mobile for EE, a pedometer for steps, and a Polar heart rate strap worn on the chest for heart rate. For estimating whole-trial EE, the mean absolute percent error (MAPE) from Fitbit Charge HR (32.9%) was more than twice that of Apple Watch 1 (15.2%). This trend was consistent for the individual conditions. Both monitors accurately assessed steps during aerobic activity (MAPEApple: 6.2%; MAPEFitbit: 9.4%) but overestimated steps in light physical activity. For heart rate, Fitbit Charge HR produced its smallest MAPE in sedentary behaviors (7.2%), followed by aerobic exercise (8.4%), and light activity (10.1%). The Apple Watch 1 had stronger validity than the Fitbit Charge HR for assessing overall EE and steps during aerobic exercise. The Fitbit Charge HR provided heart rate estimates that were statistically equivalent to Polar monitor.  相似文献   

4.
This study examined whether or not activity monitor data collected as part of a typical 7-day physical activity (PA) measurement protocol can be expected to be missing at random. A total of 315 participants (9–18 years) each wore a SenseWear Armband monitor for 7 consecutive days. Participants were classified as “compliant” (86 boys and 124 girls) if they had recorded accelerometer data during 70% or more of the predefined awake time (7 AM–10 PM) on four different days; and “non-compliant” (44 boys and 51 girls) when not meeting these criteria. Linear mixed models were used to examine differences in energy expenditure (EE) levels by compliance across 10 different time periods. The results indicated that non-compliant girls were older (13.4 ± 2.9 vs. 12.2 ± 2.5) and taller (156.8 ± 10.3 vs. 152.8 ± 11.3) than their same gender compliant peers (P < .05). Comparisons of EE rates at segmented portions of the day revealed no differences between compliant and non-compliant groups (P ≥ .05). Differences in EE ranged from ?0.32 kcal · kg?1 · h?1 (before school time) to 0.62 kcal · kg?1 · h?1 (physical education class) in boys and ?0.39 kcal · kg?1 · h?1 (transportation from school) to 0.37 kcal · kg?1 · hour?1 (recess) in girls. The results showed that compliant and non-compliant individuals differed in a few demographic characteristics but exhibited similar activity patterns. This suggests that data were considered to be missing at random, but additional work is needed to confirm this observation in a representative sample of children using other types of activity monitors and protocols.  相似文献   

5.
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6.
Abstract

In this study, we examined thermoregulatory responses to ingestion of separate aliquots of drinks at different temperatures during low-intensity exercise in conditions of moderate heat stress. Eight men cycled at 50% (s = 3) of their peak oxygen uptake ([Vdot]O2peak) for 90 min (dry bulb temperature: 25.3°C, s = 0.5; relative humidity: 60%, s = 5). Four 400-ml aliquots of flavoured water at 10°C (cold), 37°C (warm) or 50°C (hot) were ingested after 30, 45, 60, and 75 min of exercise. Immediately after the 90 min of exercise, participants cycled at 95%[Vdot]O2peak to exhaustion to assess exercise capacity. There were no differences between trials in rectal temperature at the end of the 90 min of exercise (cold: 38.11°C, s = 0.30; warm: 38.10°C, s = 0.33; hot: 38.21°C, s = 0.30; P = 0.765). Mean skin temperature between 30 and 90 min tended to be influenced by drink temperature (cold: 34.49°C, s = 0.64; warm: 34.53°C, s = 0.69; hot: 34.71°C, s = 0.48; P = 0.091). Mean heart rate from 30 to 90 min was higher in the hot trial (129 beats · min?1, s = 7; P < 0.05) than on the cold (124 beats · min?1, s = 9) and warm trials (126 beats · min?1, s = 8). Ratings of thermal sensation were higher on the hot trial than on the cold trial at 35 and 50 min (P < 0.05). Exercise capacity was similar between trials (P = 0.963). The heat load and debt induced by periodic drinking resulted in similar body temperatures during low-intensity exercise in conditions of moderate heat stress due to appropriate thermoregulatory reflexes.  相似文献   

7.
Abstract

Nine males cycled at 53% (s = 2) of their peak oxygen uptake ([Vdot]O2peak) for 90 min (dry bulb temperature: 25.4°C, s = 0.2; relative humidity: 61%, s = 3). One litre of flavoured water at 10 (cold), 37 (warm) or 50°C (hot) was ingested 30 – 40 min into exercise. Immediately after the 90 min of exercise, participants cycled at 95%[Vdot]O2peak to exhaustion to assess exercise capacity. Rectal and mean skin temperatures and heart rate were recorded. The gradient of rise in rectal temperature was influenced (P < 0.01) by drink temperature. Mean skin temperature was highest in the hot trial (cold trial: 34.2°C, s = 0.5; warm trial: 34.4°C, s = 0.5; hot trial: 34.7°C, s = 0.6; P < 0.01). Significant differences were observed in heart rate (cold trial: 132 beats · min?1, s = 13; warm trial: 134 beats · min?1, s = 12; hot trial: 139 beats · min?1, s = 13; P < 0.05). Exercise capacity was similar between trials (cold trial: 234 s, s = 69; warm trial: 214 s, s = 52; hot trial: 203 s, s = 53; P = 0.562). The heat load and debt induced via drinking resulted in appropriate thermoregulatory reflexes during exercise leading to an observed heat content difference of only 33 kJ instead of the predicted 167 kJ between the cold and hot trials. These results suggest that there may be a role for drink temperature in influencing thermoregulation during exercise.  相似文献   

8.
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9.
针对中国大学生人群,选择7项日常体力活动方式,通过三轴加速度传感器监控,构建不同类型运动项目的能量消耗预测模型。研究结果表明：（1）通过佩戴传感器,可以有效对运动过程进行记录,每种运动形式特征明显。（2）不同类型的运动之间具有显著性差异,同一种运动方式不同速度之间没有差异,说明传感器可以有效区分运动类型。（3）将加速度值进行分析,构建基于垂直加速度Vcz和综合加速度值VM的能量消耗模型,分别为：W/min=-9.173+0.004×ACz+1.09×Sex+0.241×BMI+0.060×HR,W/min=-12.57+0.008×VM+0.921×SEX+0.242×BMI+0.053×HR （M=1,F=0）。（4）通过回带验证,两个能量消耗方程均有很好的拟合度,预测结果与实际值很接近。  相似文献   

10.
Abstract

A comparative evaluation of the ability of activity monitors to predict energy expenditure (EE) is necessary to aid in the investigation of the effect of EE on health. The purpose of this study was to validate and compare the RT3, the SWA and the IDEEA at measuring EE in adults and children. Twenty-six adults and 22 children completed a resting metabolic rate (RMR) test and performed four treadmill activities at 3 km.h?1, 6 km.h?1, 6 km.h?1 at a 10% incline, 9 km.h?1. EE was assessed throughout the protocol by the RT3, the SWA and the IDEEA. Indirect calorimetry (IC) was used as a criterion measure of EE against which each monitor was compared. Mean bias was assessed by subtracting EE from IC from EE from each monitor for each activity. Limit of agreement plots were used to assess the agreement between each monitor and IC. Limits of agreement for resting EE were narrowest for the RT3 for adults and children. Although the IDEEA displayed the smallest mean bias between measures at 3 km.h?1, 6 km.h?1 and 9 km.h?1 in adults and children, the SWA agreed closest with IC at 6 km.h?1, 6 km.h?1 at a 10% incline and 9 km.h?1. Limits of agreement were closest for the SWA at 9 km.h?1 in adults representing 42% of the overall mean EE. Although the RT3 provided the best estimate of resting EE in adults and children, the SWA provided the most accurate estimate of EE across a range of physical activity intensities.  相似文献   

11.
The purpose of this study was to assess the accuracy of energy expenditure (EE) estimation and step tracking abilities of six activity monitors (AMs) in relation to indirect calorimetry and hand counted steps and assess the accuracy of the AMs between high and low fit individuals in order to assess the impact of exercise intensity. Fifty participants wore the Basis watch, Fitbit Flex, Polar FT7, Jawbone, Omron pedometer, and Actigraph during a maximal graded treadmill test. Correlations, intra-class correlations, and t-tests determined accuracy and agreement between AMs and criterions. The results indicate that the Omron, Fitbit, and Actigraph were accurate for measuring steps while the Basis and Jawbone significantly underestimated steps. All AMs were significantly correlated with indirect calorimetry, however, no devices showed agreement (p < .05). When comparing low and high fit groups, correlations between AMs and indirect calorimetry improved for the low fit group, suggesting AMs may be better at measuring EE at lower intensity exercise.  相似文献   

12.
ABSTRACT

Purpose: To compare children’s energy expenditure (EE) levels during object projection skill performance (OPSP; e.g., kicking, throwing, striking) as assessed by hip- and wrist-worn accelerometers. Method: Forty-two children (female n = 20, Mage = 8.1 ± 0.8 years) performed three, nine-minute sessions of kicking, over-arm throwing, and striking at performance intervals of 6, 12, and 30 seconds. EE was estimated using indirect calorimetry (COSMED k4b2) and accelerometers (ActiGraph GT3X+) worn on three different locations (hip, dominant-wrist, and non-dominant-wrist) using four commonly used cut-points. Bland-Altman plots were used to analyze the agreement in EE estimations between accelerometry and indirect calorimetry (METS). Chi-square goodness of fit tests were used to examine the agreement between accelerometry and indirect calorimetry. Results: Hip- and wrist-worn accelerometers underestimated EE, compared to indirect calorimetry, during all performance conditions. Skill practice at a rate of two trials per minute resulted in the equivalent of moderate PA and five trials per minute resulted in vigorous PA (as measured by indirect calorimetry), yet was only categorized as light and/or moderate activity by all measured forms of accelerometry. Conclusion: This is one of the first studies to evaluate the ability of hip- and wrist-worn accelerometers to predict PA intensity levels during OPSP in children. These data may significantly impact PA intervention measurement strategies by revealing the lack of validity in accelerometers to accurately predict PA levels during OPSP in children.  相似文献   

13.
Outdoor exercise often proceeds in rainy conditions. However, the cooling effects of rain on human physiological responses have not been systematically studied in hot conditions. The present study determined physiological and metabolic responses using a climatic chamber that can precisely simulate hot, rainy conditions. Eleven healthy men ran on a treadmill at an intensity of 70% VO2max for 30 min in the climatic chamber at an ambient temperature of 33°C in the presence (RAIN) or absence (CON) of 30 mm · h?1 of precipitation and a headwind equal to the running velocity of 3.15 ± 0.19 m · s?1. Oesophageal temperature, mean skin temperature, heart rate, rating of perceived exertion, blood parameters, volume of expired air and sweat loss were measured. Oesophageal and mean skin temperatures were significantly lower from 5 to 30 min, and heart rate was significantly lower from 20 to 30 min in RAIN than in CON (P < 0.05 for all). Plasma lactate and epinephrine concentrations (30 min) and sweat loss were significantly lower (P < 0.05) in RAIN compared with CON. Rain appears to influence physiological and metabolic responses to exercise in heat such that heat-induced strain might be reduced.  相似文献   

14.
In this study we examined the performance during, and the physiological and metabolic responses to, prolonged, intermittent, high-intensity shuttle running in hot (～30 C, dry bulb temperature) and moderate (～20 C) environmental conditions. Twelve male students, whose mean (s x ) age, body mass and maximal oxygen uptake (V O 2m ax ) were 22 ± 1 years, 69.8 ± 01.8 kg and 56.9 ± 1.1 ml . kg ?1 . min ?1 respectively, performed intermittent high- and low-speed running involving five sets of ～15 min of repeated cycles of walking and variable speed running followed by 60 s run/rest exercise until fatigue. The total distance completed in the hot and moderate trials was 8842 3790 m and 11,280 214 m respectively (P < 0.01). This decrement in performance occurred even though no differences existed in the level of dehydration, rating of perceived exertion, blood glucose and lactate, plasma free fatty acid and ammonia concentrations between the two trials. However, water consumption was almost twice as great in the hot trial (hot vs moderate: 1.18 ± 0.12 vs 0.63 ± 0.07 l . h ?1 , P < 0.01). Rectal temperature (hot vs moderate: 39.4 ± 0.1 vs 38.0 ± 0.1 C, P < 0.01) and heart rate (hot vs moderate: 186 ± 2 vs 179 ± 2 beats . min ?1 , P < 0.05) were higher at the end of the hot condition than at the same point in time in the moderate condition. The correlation between the rate of rise in rectal temperature and the distance completed during the hot condition was -0.94 (P < 0.01); for the moderate condition it was -0.65 (P <0.05). The reduced performance in the hot condition was associated with high body temperature; the precise mechanisms by which the performance decrement was brought about are, however, unclear.  相似文献   

15.
Abstract

This study examined the effects of caffeine, co-ingested with a high fat meal, on perceptual and metabolic responses during incremental (Experiment 1) and endurance (Experiment 2) exercise performance. Trained participants performed three constant-load cycling tests at approximately 73% of maximal oxygen uptake ([Vdot]O2max) for 30 min at 20°C (Experiment 1, n = 8) and to the limit of tolerance at 10°C (Experiment 2, n = 10). The 30 min constant-load exercise in Experiment 1 was followed by incremental exercise (15 W · min?1) to fatigue. Four hours before the first test, the participants consumed a 90% carbohydrate meal (control trial); in the remaining two tests, the participants consumed a 90% fat meal with (fat + caffeine trial) and without (fat-only trial) caffeine. Caffeine and placebo were randomly assigned and ingested 1 h before exercise. In both experiments, ratings of perceived leg exertion were significantly lower during the fat + caffeine than fat-only trial (Experiment 1: P < 0.001; Experiment 2: P < 0.01). Ratings of perceived breathlessness were significantly lower in Experiment 1 (P < 0.01) and heart rate higher in Experiment 2 (P < 0.001) on the fat + caffeine than fat-only trial. In the two experiments, oxygen uptake, ventilation, blood [glucose], [lactate] and plasma [glycerol] were significantly higher on the fat + caffeine than fat-only trial. In Experiment 2, plasma [free fatty acids], blood [pyruvate] and the [lactate]:[pyruvate] ratio were significantly higher on the fat + caffeine than fat-only trial. Time to exhaustion during incremental exercise (Experiment 1: control: 4.9, s = 1.8 min; fat-only: 5.0, s = 2.2 min; fat + caffeine: 5.0, s = 2.2 min; P > 0.05) and constant-load exercise (Experiment 2: control: 116 (88 – 145) min; fat-only: 122 (96 – 144) min; fat + caffeine: 127 (107 – 176) min; P > 0.05) was not different between the fat-only and fat + caffeine trials. In conclusion, while a number of metabolic responses were increased during exercise after caffeine ingestion, perception of effort was reduced and this may be attributed to the direct stimulatory effect of caffeine on the central nervous system. However, this caffeine-induced reduction in effort perception did not improve exercise performance.  相似文献   

16.
This study examined the validity of the Actical accelerometer step count and energy expenditure (EE) functions in healthy young adults. Forty-three participants participated in study 1. Actical step counts were compared to actual steps taken during a 200 m walk around an indoor track at self-selected pace and during treadmill walking at different speeds (0.894, 1.56 and 2.01 m · s–1) for 5 min. The Actical was also compared to three pedometers. For study 2, 15 participants from study 1 walked on a treadmill at their predetermined self-selected pace for 15 min. Actical EE was compared to EE measured by indirect calorimetry. One-way analysis of variance and t-tests were used to examine differences. There were no statistical difference between Actical steps and actual steps in self-selected pace walking and during treadmill walking at moderate and fast speeds. During treadmill walking at slow speed, the Actical step counts significantly under predicted actual steps taken. For study 2, there was no statistical difference between measured EE and Actical-recorded EE. The Actical provides valid estimates of step counts at self-selected pace and walking at constant speeds of 1.56 and 2.01 m · s–1. The Actical underestimates EE of walking at constants speeds ≥1.38 m · s–1.  相似文献   

17.
Introduction: Wearable activity monitors have been developed for jump height assessment, but the Blast Athletic Performance monitor has not yet been validated, and it remains unclear if the Blast can track changes across a sports season. Methods: Collegiate women’s volleyball players (n = 20) wore the Blast monitor (waistband) while performing standing vertical jumps (SVJs) and one-step vertical jumps (OSJs) weekly during and after a 9-week season. Jump heights from the Blast were compared to a Vertec (criterion). Results: Correlations of Blast and Vertec were moderately high (r = 0.67–0.69), but the Blast underestimated SVJ and OSJ (9.2–10.0 cm), with mean absolute percent errors 19.8–21.0%. A + 23% correction factor reduced errors to 10.5–11.3%. The Blast did not detect small decreases (2–4 cm) in criterion-measured jump height in the postseason. Conclusion: The Blast underestimated jump height and had limited ability to detect changes of up to 5.0 cm following a volleyball season. A relative correction lowered, but did not eliminate, measurement error.  相似文献   

18.
Exercising in the cold is not an attractive option for many athletes; however, defining what represents cold is difficult and is not standard for all events. If the exercise is prolonged and undertaken at a moderate intensity, environmental temperatures around 11°C can be an advantage. If the intensity is lower than this value and the individual does not generate sufficient metabolic heat to offset the effects imposed by the cold environment, then temperatures of 11°C can be detrimental to performance. Similarly, when the performance involves dynamic explosive contractions, then a cold ambient temperature can have a negative influence. Additional factors such as the exercising medium, air or water, and the anthropometric characteristics of the athlete will also make a difference to the strategies that can be adopted to offset any negative impact of a cold environment on performance. To plan for a performance in the cold requires an understanding of the mechanisms underpinning the physiological response. This review attempts to outline these mechanisms and how they can be manipulated to optimize performance.  相似文献   

19.
This study examined the influence of body composition on temperature and blood flow responses to post-exercise cold water immersion (CWI), hot water immersion (HWI) and control (CON). Twenty-seven male participants were stratified into three groups: 1) low mass and low fat (LM-LF); 2) high mass and low fat (HM-LF); or 3) high mass and high fat (HM-HF). Experimental trials involved a standardised bout of cycling, maintained until core temperature reached 38.5°C. Participants subsequently completed one of three 15-min recovery interventions (CWI, HWI, or CON). Core, skin and muscle temperatures, and limb blood flow were recorded at baseline, post-exercise, and every 30 min following recovery for 240 min. During CON and HWI there were no differences in core or muscle temperature between body composition groups. The rate of fall in core temperature following CWI was greater in the LM-LF (0.03 ± 0.01°C/min) group compared to the HM-HF (0.01 ± 0.001°C/min) group (P = 0.002). Muscle temperature decreased to a greater extent during CWI in the LM-LF and HM-LF groups (8.6 ± 3.0°C) compared with HM-HF (5.1 ± 2.0°C, P < 0.05). Blood flow responses did not differ between groups. Differences in body composition alter the thermal response to post-exercise CWI, which may explain some of the variance in the responses to CWI recovery.  相似文献   

20.
为探讨一次大强度耐力运动过程中,AMPK活性变化对骨骼肌蛋白质降解的作用。将36只SD大鼠进行一次跑台运动,坡度5%,运动强度25 m/min,运动时间60 min。取样为运动前、运动0.5、1 h,运动后1、2、6 h等6个点。使用高效液相色谱法测定AMP、ATP质量摩尔浓度;采用同位素技术测定腓肠肌中AMPK活性的变化;采用荧光定量PCR技术,测定腓肠肌中MuRF1、MAFbx基因表达量的变化。结果发现:(1)运动0.5 h到运动后即刻,AMP质量摩尔浓度及AMP与ATP质量摩尔浓度比值升高(P<0.05),运动后1、2、6 h组,腓肠肌AMP质量摩尔浓度及AMP、ATP质量摩尔浓度比值与安静组比较差异没有显著性;ATP质量摩尔浓度各组变化不大,差异没有显著性。(2)AMPK活性在运动0.5 h后开始升高,运动后2 h达到最高,运动后6 h开始下降但还高于对照组。(3)与安静组比较,运动0.5 h组、运动1 h组MuRF1 mRNA、MAFbx mRNA表达量差异没有显著性;运动后1 h、2 h组MuRF1 mRNA、MAFbx mRNA表达量与安静组比较升高,差异有非常显著性(P<0.01),分别升高1.98、3.57和1.95、2.55倍;运动后6 h组MuRF1 mRNA、MAFbx mRNA表达量与安静组比较升高,差异有显著性(P<0.05)。结果说明:一次性大强度耐力运动后1~6 h,骨骼肌蛋白质降解可能增强,其原因可能是AMPK活化,促进MAFbx mRNA、MuRF1 mRNA基因表达,促进骨骼肌蛋白质的降解。  相似文献   

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