Accuracy of an infrared LED device to measure heart rate and energy expenditure during rest and exercise

Abstract

The purpose of this study was to examine the accuracy of the ePulse Personal Fitness Assistant, a forearm-worn device that provides measures of heart rate and estimates energy expenditure. Forty-six participants engaged in 4-minute periods of standing, 2.0 mph walking, 3.5 mph walking, 4.5 mph jogging, and 6.0 mph running. Heart rate and energy expenditure were simultaneously recorded at 60-second intervals using the ePulse, an electrocardiogram (EKG), and indirect calorimetry. The heart rates obtained from the ePulse were highly correlated (intraclass correlation coefficients [ICCs] ≥0.85) with those from the EKG during all conditions. The typical errors progressively increased with increasing exercise intensity but were <5 bpm only during rest and 2.0 mph. Energy expenditure from the ePulse was poorly correlated with indirect calorimetry (ICCs: 0.01–0.36) and the typical errors for energy expenditure ranged from 0.69–2.97 kcal · min^?1, progressively increasing with exercise intensity. These data suggest that the ePulse Personal Fitness Assistant is a valid device for monitoring heart rate at rest and low-intensity exercise, but becomes less accurate as exercise intensity increases. However, it does not appear to be a valid device to estimate energy expenditure during exercise.     

Validity of the Smarthealth Watch to Measure Heart Rate During Rest and Exercise

The purpose of this study was to examine the validity of the Smarthealth watch (Salutron, Inc., Fremont, California, USA), a heart rate monitor that includes a wristwatch without an accompanying chest strap. Twenty-five individuals participated in 3-min periods of standing, 2.0 mph walking, 3.5 mph walking, 4.5 mph jogging, and 6.0 mph running. Heart rate was simultaneously measured and recorded at 60-sec intervals using three methods: the Smarthealth wristwatch, the Polar Vantage XL monitor with an accompanying chest strap (Kempele, Finland), and an electrocardiograph, which served as the criterion method. The heart rates obtained from the Smarthealth watch were highly correlated with those from the electrocardiograph (r ≥ .95) and the standard error of estimate was below 5 bpm for all measurements. Additionally, correlation coefficients and standard errors of estimate between the Smarthealth watch and Polar heart rate monitor were ≥.97 and <3.7 bpm, respectively. However, the Smarthealth watch exhibited a reduced ability to detect a heart rate during the 4.5 and 6.0 mph conditions compared to the Polar heart rate monitor (6% and 13.9% reduced ability, respectively). The Smarthealth watch appears to be a valid device for monitoring heart rate while standing and during treadmill exercise involving walking and jogging in a healthy young adult sample, although it may not be able to consistently detect a heart rate when body motion is excessive.     

Energy Expenditure and Intensity of Active Video Games in Children and Adolescents

Purpose: This study aimed to compare the energy expenditure and intensity of active video games to that of treadmill walking in children and adolescents. Method: Seventy-two boys and girls (aged 8–13 years) were recruited from local public schools. Energy expenditure and heart rate were measured during rest, during 3-km/hr, 4-km/hr, and 5-km/hr walks, and during active games (Adventure, Boxing I, Boxing II, and Dance). During walking and active games, we also assessed physical activity using an accelerometer. Results: The energy expenditure of the active games Adventure, Boxing I, Boxing II, and Dance was similar to that of treadmill walking at 5 km/hr in boys and girls. Heart rate was significantly higher for the game Adventure compared with walking at 3 km/hr, 4 km/hr, and 5 km/hr and the game Dance in both genders. The heart rate of girls during the games Adventure and Dance was significantly higher compared with boys. There was a statistically significant difference (p < .05, with an effect size ranging from 0.40 to 3.54) in the counts·min^?1, measured through accelerometry, between activities. Conclusion: XBOX 360 Kinect games provide energy expenditure and physical activity of moderate intensity for both genders. The use of active video games can be an interesting alternative to increase physical activity levels.     

Using Principal Components Analysis to Identify Individual Differences in Vertical Jump Performance

Purpose: The purpose of this study was to determine the reliability of cardiorespiratory and pelvic kinematic responses to simulated horseback riding (SHBR) and to characterize responses to SHBR relative to walking in apparently healthy children. Method: Fifteen healthy children (M_age = 9.5 ± 2.6 years) completed SHBR on a commercially available simulator at low intensity (0.27 Hz) and high intensity (0.65 Hz) during 3 sessions on different occasions. Heart rate (HR), blood pressure, and respiratory gases were measured at rest and during steady-state exercise at both intensities. Pelvic displacement was measured during steady-state exercise. Rate of energy expenditure, mean arterial pressure, and rate pressure product (RPP) were calculated. Participants also walked on a treadmill for 26.8 m/min to 80.5 m/min in 13.4-m/min increments at 0% grade during 1 session to compare cardiorespiratory responses with those of SHBR. Results: Physiological variables across all 3 SHBR sessions were similar at both intensities (p>.05 for all). Intraclass correlation coefficients (ICCs) and coefficients of variation indicate good to modest reliability of cardiorespiratory measures during SHBR (ICCs = .542–.996 for oxygen consumption, energy expenditure, and RPP). Cardiorespiratory variables, except for HR, were 2% to 19% greater, and pelvic displacement was up to 37% greater with high-intensity riding. Treadmill walking at all speeds elicited greater physiological responses compared with SHBR (p < .05). Conclusion: Cardiorespiratory responses and pelvic kinematics are reproducible with SHBR in young children, and these responses were lower than those elicited by slow treadmill walking.     

Validity of SenseWear® Armband v5.2 and v2.2 for estimating energy expenditure

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.     

跑台上走、跑能量消耗与运动速度的相关关系研究

目的:研究走、跑模式下健康成年男子单位时间单位体重的能量消耗与运动速度的相关关系以及单位距离单位体重的能量消耗与运动速度的相关关系;探讨相同速度走、跑两种不同的运动模式下能量消耗特征;方法:19名男性大学生作为研究对象。使用跑台控制速度,采用走、跑两种运动模式,每一速度至少测试6min,以速度递增的方式进行测试,走、跑模式转换时休息至安静状态。使用VO2000测试安静以及运动中的气体代谢参数,PO-LAR表测试心率;结果:建立走模式以及跑模式下的能量消耗与速度之间的拟合方程;单位时间单位体重的能耗与走速二次曲线拟合方程的复相关系数r2=0.88;单位时间单位体重的能耗与跑速线性拟合方程的复相关系数r2=0.72;两条拟合曲线的交点坐标为(2.35m/s,141.7cal/kg/min);在测试速度范围之内,同等速度下走与跑的单位时间的能耗具有显著性差异(P<0.01),跑的能耗显著大于走的能耗。单位距离单位体重的能耗与走速的2次拟合曲线的复相关系数r2=0.98,曲线最低点的坐标为(1.14m/s,0.553cal/kg/m),单位距离单位体重的平均能耗与跑速拟合曲线的复相关系数r2=0.68;结论:1)单位时间单位体重的能耗与走速呈二次曲线关系,单位时间单位体重的能耗与跑速呈线性递增关系;2)单位距离单位体重的能耗与走速呈"U"型曲线关系;单位距离单位体重的能耗与跑速呈线性递减趋势,说明在一定速度范围内随着跑速的增加单位距离单位体重的能耗降低。     

The effect of exercise intensity on coincidence anticipation performance at different stimulus speeds

Abstract

The aim of this study was to examine the effect of exercise intensity on coincidence anticipation timing [CAT] performance at different stimulus speeds. Fourteen young adults (11 males and 3 females) volunteered to participate in the study following ethical approval. After familiarisation, coincidence anticipation was measured using the Bassin Anticipation Timer under three conditions: rest, moderate-intensity and high-intensity exercise with stimulus speeds of 3, 5 and 8 mph, set using an incremental running protocol until the participants reached a steady state of 70% and 90% of heart rate reserve (HRR), respectively. Results indicated a significant exercise intensity×stimulus speed interaction (p=0.0001) for absolute error (AE). There were no significant differences in AE across exercise intensities at a stimulus speed of 3 mph (p>0.05). AE was poorer during high-intensity exercise (90% HRR) compared to rest (p=0.022), and moderate-intensity (70% HRR) exercise (all, p=0.004 or better) at 5 and 8 mph. Variable error (VE) was similar across exercise intensities at stimulus speeds of both 3 and 5 mph (p>0.05). At a stimulus speed of 8 mph, VE was significantly poorer during high-intensity exercise compared to rest (p=0.006) and moderate-intensity exercise (p=0.008). There were no significant differences for constant error (p>0.05) across exercise intensities or stimulus speeds. High-intensity exercise is associated with poorer CAT performance. However, stimulus speed plays a key role within this association where faster stimulus speeds were associated with a more marked decrease in coincidence anticipation performance.     

Validity of wearable activity monitors for tracking steps and estimating energy expenditure during a graded maximal treadmill test

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.     

Assessment of energy expenditure in children using the RT3 accelerometer

The aim of this study was to evaluate the utility of the RT3 accelerometer in young children, compare its accuracy with heart rate monitoring, and develop an equation to predict energy expenditure from RT3 output. Forty-two volunteers (mean age 12.2 years, s = 1.1) exercised at two horizontal and graded walking speeds (4 and 6 km.h(-1), 0% grade and 6% grade), and one horizontal running speed (8 km.h(-1), 0% grade), on a treadmill. Energy expenditure and oxygen consumption (VO2) served as the criterion measures. Comparison of RT3 estimates (counts and energy expenditure) demonstrated significant differences at 4, 6, and 8 km.h(-1) on level ground (P < 0.01), while no significant differences were noted between horizontal and graded walking at 4 and 6 km.h(-1). Correlation and regression analyses indicated no advantage of vector magnitude over the vertical plane (X) alone. A strong relationship between RT3 estimates and indirect calorimetry across all speeds was obtained (r = 0.633-0.850, P < 0.01). A child-specific prediction equation (adjusted R2 = 0.753) was derived and cross-validated that offered a valid energy expenditure estimate for walking/running activities. Despite recognized limitations, the RT3 may be a useful tool for the assessment of children's physical activity during walking and running.     

健身拳对中学生心血管系统的影响

通过对普通中学生健身拳全套演练过程中心率和血压生理指标的动态监测,分析健身拳的运动强度和运动规律,并进行运动强度个人感觉评价指标对照,结果表明：健身拳的运动强度和运动量,符合全民健身活动的标准,中学生通过健身拳的练习对心血管系统的发育能够起到积极的促进作用,可以取得良好的健身效果。     

Comparing the Validity and Output of the GT1M and GT3X Accelerometer in 5- to 9-Year-Old Children

The purpose of this study was to compare the validity and output of the biaxial ActiGraph GT1M and the triaxial GT3X (ActiGraph, LLC, Pensacola, FL, USA) accelerometer in 5- to 9-year-old children. Thirty-two children wore the two monitors while their energy expenditure was measured with indirect calorimetry. They performed four locomotor and four play activities in an exercise laboratory and were further measured during 12 minutes of a sports lesson. Validity evidence in relation to indirect calorimetry was examined with linear regression equations applied to the laboratory data. During the sports lessons predicted energy expenditure according to the regression equations was compared to measured energy expenditure with the Wilcoxon-signed rank test and the Spearman correlation. To compare the output, agreement between counts of the two monitors during the laboratory activities was assessed with Bland-Altman plots. The evidence of validity was similar for both monitors. Agreement between the output of the two monitors was good for vertical counts (mean bias =??14 ± 22 counts) but not for horizontal counts (?17 ± 32 counts). The current results indicate that the two accelerometer models are able to estimate energy expenditure of a range of physical activities equally well in young children. However, they show output differences for movement in the horizontal direction.     

体力活动测量方法研究进展

体力活动水平与健康之间存在着剂量反应,如何准确测量体力活动水平是研究人员关心的问题。本文综述了体力活动研究的几种主要方法:行为观察法,双标水法,间接热量测量法,心率法,运动传感器法,问卷法。双标水法被认为是人体能量消耗测量的金标准,间接热量测量法也经常被用来校正其他测量方法,但这两种方法很难在大规模人群中应用。运动传感器和问卷法是在大规模人群中应用比较多的两种方法。     

优秀耐力运动员逐级递增负荷运动中心钠素与心血管功能变化的研究

本文采用放射免疫方法测定血浆心钠素与采用超声心动法测定心功能相结合,对10名优秀的耐力运动员和10名普通大学生进行了逐级递增负荷运动试验,以探讨运动中心脏内分泌与心血管功能的变化及其相互关系。结果发现:心脏不仅是心钠素的产生和释放部位,也是心钠素作用的靶器官之一。     

Validation of the SenseWear Armband in different ambient temperatures

This study examines the validity of the SenseWear Armband in different temperatures using the old (SenseWear v2.2) and newest version of the algorithm (SenseWear v5.2) against indirect calorimetry (IC). Thirty-nine male and female students (21.1 ± 1.41 years) completed an exercise trial in 19°C, 26°C and 33°C consisting of 5 min standing followed by alternating walking/running at 35% and 65% of their maximal oxygen uptake. The accuracy of the algorithms was evaluated by comparing estimated energy expenditure (EE) to IC using a mixed-model design. No difference was reported in EE between the different temperatures for IC. Both algorithms estimated EE significantly higher when exercising at high intensity in 33°C compared to 19°C. Compared to IC, SenseWear v2.2 accurately estimated EE during standing and light intensity exercise but underestimated EE when exercising in a hot environment and at high intensity. SenseWear v5.2 showed a difference when exercising at high intensity in thermoneutral and warm conditions. The new algorithm improved EE estimation in hot environments and at high intensity compared to the old version. However, given the inherent inaccuracy of the EE estimates of SenseWear, greater weight should be given to direct monitor outputs rather than the ability of a monitor to estimate EE precisely.     

Estimates of the number of people in England who attain or exceed vigorous intensity exercise by walking at 3 mph

Walking is a safe, accessible and low cost activity, amenable to change and known to have great potential to increase physical activity levels in sedentary individuals. The objective of this study is to estimate the proportion of the 2009 adult population of England who would attain or exceed vigorous intensity activity (>70% maximum heart rate [HR(max)]) by walking at 3 mph. We conducted predictive impact modelling using participants' (n = 1741, aged 25-64 years) cardiovascular fitness data from treadmill walking tests. We combined this data with English population estimates adjusted for age and sex to estimate the numbers of individuals that would exceed 70% HR(max) (an intensity considered sufficient for fitness gains) when walking at 3 mph (4.8 km · h(-1)). We estimate 1.5 million men (95% confidence interval [CI] 0.9-2.2 million) (from 13.4 million corresponding to 11.6% (95% CI 7.0-16.2%)) and 3.9 million women (95% CI 3.0-4.8 million) (from 13.6 million corresponding to 28.6% (95% CI 22.0-35.1%)) in England aged 25-64 years would benefit from regularly walking at 3 mph. In total, a projected 5.4 million individuals (95% CI 3.9-6.9 million) aged 25-64 (from 26.97 million corresponding to 20.1% (95% CI 14.6-25.7%)) could benefit from walking at 3 mph. Our estimates suggest a considerable number of individuals in the English population could receive fitness and health benefits by walking regularly at 3 mph. Physical activity messages that promote walking at this speed may therefore have the potential to significantly impact national fitness levels and health in England.     

Comparison of three methods of estimating energy expenditure: caltrac, heart rate, and video analysis

This study examined the accuracy of a new device (Caltrac) in estimating energy expenditure via acceleration measurements. Energy expenditure of 20 high school students during basketball class activity (average length = 37 min) was estimated using the Caltrac, heart rate recording, and video analysis. Heart rate recording and video analysis estimates of energy expenditure were determined from heart rate, caloric expenditure curves, and an activity rating scale, respectively. The following estimates of caloric expenditure (M +/- SD) were found: heart rate recording = 196 +/- 73 greater than Caltrac = 163 +/- 49 greater than film analysis = 123 +/- 30 kcal (p less than .05). Laboratory simulations of the basketball activity revealed that the Caltrac energy expenditure was not significantly different from the actual energy expenditure (p greater than .05). The heart rate recording and video analysis estimates of energy expenditure were significantly (p less than .05) higher and lower, respectively, than the actual energy expenditure. The Caltrac is a lightweight, low-cost device that provides a relatively accurate estimate of energy expenditure in free-ranging activities, such as basketball.     

Validity of the ActiGraph GT1M during walking and cycling

Abstract

The ActiGraph activity monitors have developed and newer versions of the ActiGraph accelerometers (GT1M, GT3X and GT3X +) are now available, including changes in hardware and software compared to the old version (AM7164). This is problematic as most of the validation and calibration work includes the AM7164. The aims of the study were to validate the ActiGraph GT1M during level and graded walking and to assess the potential underestimation of physical activity during cycling. Data were obtained from 20 participants during treadmill walking and ergometer cycling. Energy expenditure was measured via indirect calorimetry and used as the criterion method. Activity counts were highly correlated with energy expenditure during level walking (R² = 0.82) and graded walking at 5% and 8% (R² = 0.82 and R² = 0.67, respectively). There was no linear relationship between activity counts and energy expenditure during cycling. The average activity counts for all data points during cycling was 1,157 counts per minute (CPM) (SD = 974), and mean energy expenditure was 5.0 metabolic equivalents. The GT1M is a valid tool for assessing walking across a wide range of speeds and gradients. However, there is no relationship between activity counts and energy expenditure during cycling and physical activity is underestimated by ≈73% during cycling compared to walking.     

Direct and indirect calorimetry of lactate oxidation: implications for whole-body energy expenditure

Whole-body energy expenditure for heavy/severe exercise is currently accounted for by either: (1) anaerobic and oxygen uptake measures during exercise where recovery energy expenditure is omitted; or (2) oxygen uptake during, and an EPOC (excess post-exercise oxygen consumption), measure following exercise where substrate level phosphorylation during exercise is considered part of EPOC. Simultaneous direct/indirect calorimetry enabled us to determine if a thermodynamic reversal (i.e. heat consumption) takes place as the highly exothermic pyruvate to lactate reaction proceeds in the opposite direction. Reversibility implies that oxygen uptake (e.g. EPOC) can indeed account for rapid glycolytic ATP production regardless if lactate is formed or not (e.g. 1.2 g glucose catabolism = 20.9 kJ x l O2(-1)). Cultured hybrid cells and mouse cardiac muscle fibres were utilized in simultaneous calorimetry and respirometry experiments where pyruvate or lactate was predominantly oxidized. The calorimetric to respiratory ratio was determined using heat flux (pW x cell(-1)) and oxygen flux (pmol x s(-1) cell(-1)) measures. Ten cell experiments gave calorimetric to respiratory ratios that showed no statistical difference (P= 0.97) whether cells respired predominantly on lactate (-516+/-53 kJ x mol O2(-1)) or pyruvate (- 517+/-89 kJ x mol O2(-1)). In three cardiac preparations, the calorimetric to respiratory ratio was -502+/-15 kJ x mol O2(-1) for lactate and -506+/-47 kJ x mol O2(-1) for pyruvate, again a non-significant difference (P= 0.91). Heat consumption did not occur during lactate oxidation. These results suggest that rapid glycolytic ATP and lactate production, and lactate oxidation, are both independently associated with heat production and thus represent separate and additive components to the measurement of total energy expenditure for exercise and recovery.     

Estimates of the number of people in England who attain or exceed vigorous intensity exercise by walking at 3 mph

Abstract

Walking is a safe, accessible and low cost activity, amenable to change and known to have great potential to increase physical activity levels in sedentary individuals. The objective of this study is to estimate the proportion of the 2009 adult population of England who would attain or exceed vigorous intensity activity (>70% maximum heart rate [HR_max]) by walking at 3 mph. We conducted predictive impact modelling using participants' (n = 1741, aged 25–64 years) cardiovascular fitness data from treadmill walking tests. We combined this data with English population estimates adjusted for age and sex to estimate the numbers of individuals that would exceed 70% HR_max (an intensity considered sufficient for fitness gains) when walking at 3 mph (4.8 km · h^?1). We estimate 1.5 million men (95% confidence interval [CI] 0.9–2.2 million) (from 13.4 million corresponding to 11.6% (95% CI 7.0–16.2%)) and 3.9 million women (95% CI 3.0–4.8 million) (from 13.6 million corresponding to 28.6% (95% CI 22.0–35.1%)) in England aged 25–64 years would benefit from regularly walking at 3 mph. In total, a projected 5.4 million individuals (95% CI 3.9–6.9 million) aged 25–64 (from 26.97 million corresponding to 20.1% (95% CI 14.6–25.7%)) could benefit from walking at 3 mph. Our estimates suggest a considerable number of individuals in the English population could receive fitness and health benefits by walking regularly at 3 mph. Physical activity messages that promote walking at this speed may therefore have the potential to significantly impact national fitness levels and health in England.     

Differences in energy expenditure between high- and low-volume training

Abstract

Several studies have examined energy expenditure in various sports but there is a lack of research on the contribution of exercise and habitual activity during different training periods. This study examined changes in total daily energy expenditure (TDEE) and its components during high- and low-volume training periods. Further, changes in time spent in sedentary, light, moderate and vigorous activity in response to different training volumes were explored. Energy expenditure was measured in 15 male endurance athletes during 2 non-consecutive weeks – 1 week of high volume (>13 hours) training and another week of low volume (<7 hours) training. The SenseWear Pro 3 Armband, individual heart-rate-oxygen consumption regression and indirect calorimetry was used to measure non-exercise activity thermogensis (NEAT), exercise energy expenditure (EEE) and resting metabolic rate, respectively. Time spent at different intensities was assessed using previously established MET cutpoints. TDEE as well as EEE increased significantly with higher training volume, while no difference in NEAT occurred. Further, significantly less time was spent in sedentary activities during the high-volume week. These results suggest that highly trained athletes do not compensate for increased training volume and reduce sedentary activities to allow for more training time.