Assessment Of Energy Expenditure Research Articles

Bath Breakfast Project (BBP)--examining the role of extended daily fasting in human energy balance and associated health outcomes: study protocol for a randomised controlled trial [ISRCTN31521726

BackgroundCurrent guidance regarding the role of daily breakfast in human health is largely grounded in cross-sectional observations. However, the causal nature of these relationships has not been fully explored and what limited information is emerging from controlled laboratory-based experiments appears inconsistent with much existing data. Further progress in our understanding therefore requires a direct examination of how daily breakfast impacts human health under free-living conditions.Methods/DesignThe Bath Breakfast Project (BBP) is a randomised controlled trial comparing the effects of daily breakfast consumption relative to extended fasting on energy balance and human health. Approximately 70 men and women will undergo extensive laboratory-based assessments of their acute metabolic responses under fasted and post-prandial conditions, to include: resting metabolic rate, substrate oxidation, dietary-induced thermogenesis and systemic concentrations of key metabolites/hormones. Physiological and psychological indices of appetite will also be monitored both over the first few hours of the day (i.e. whether fed or fasted) and also following a standardised test lunch used to assess voluntary energy intake under controlled conditions. Baseline measurements of participants' anthropometric characteristics (e.g. DEXA) will be recorded prior to intervention, along with an oral glucose tolerance test and acquisition of adipose tissue samples to determine expression of key genes and estimates of tissue-specific insulin action. Participants will then be randomly assigned either to a group prescribed an energy intake of ≥3000 kJ before 1100 each day or a group to extend their overnight fast by abstaining from ingestion of energy-providing nutrients until 1200 each day, with all laboratory-based measurements followed-up 6 weeks later. Free-living assessments of energy intake (via direct weighed food diaries) and energy expenditure (via combined heart-rate/accelerometry) will be made during the first and last week of intervention, with continuous glucose monitors worn both to document chronic glycaemic responses to the intervention and to verify compliance.Trial registrationCurrent Controlled Trials ISRCTN31521726.

Assessing Energy Expenditure in Male Endurance Athletes

The correct assessment of energy expenditure (EE) in athletes is important to ensure that dietary energy intake is sufficient. In general, athletes are individuals with especially high levels of total EE (TEE) and exercise-related EE (ExEE). The SenseWear Pro3 Armband (SWA) is a multisensor device for the individual assessment of EE, but data on the validity for higher exercise intensities are missing. The aim of the study was to validate the SWA for the assessment of TEE and ExEE in endurance athletes. The SWA was worn by 14 male endurance athletes for 7 d during a regular training period, and TEE was measured in parallel with the doubly labeled water method. Two controlled exercise trials (treadmill running=2.4-4.8 m·s, stationary bicycling=140-380 W) were performed, during which indirect calorimetry was used to assess ExEE. TEE assessed with the SWA and TEE measured with the doubly labeled water method were significantly correlated (r=0.73, P<0.01), but there were a proportional bias and considerably wide limits of agreement (-1368 to 1238 kcal·d). The error of TEE assessed with the SWA was related to the athletes' individual lactate thresholds (P<0.05). During running and bicycling, ExEE was significantly underestimated for most exercise intensities, and the underestimation increased with exercise intensity (P<0.001). According to our results, the SWA does not provide valid results of TEE and ExEE in endurance athletes because of the underestimation of EE at higher exercise intensities. It seems necessary to develop exercise-specific prediction equations to improve EE measurements in athletes.

Test–retest reliability of a portable monitor to assess energy expenditure

The ability of the SenseWear Armband (SWA) to estimate energy expenditure (EE) in adults is established. However, except for resting metabolic rate, the test-retest reliability of the SWA for the estimation of EE in adults is unknown. To explore reliability, 34 healthy adults (50% women; age, 26.7± 6.1years; body mass index, 23.6± 3.3kg·m(-2)) completed a 2-day study protocol. During 13h of direct supervision, subjects completed, each day, 60min of lying awake rest, 30min of structured sedentary activity, 45min of walking circuit, and 45min of ergocycling at 50% of their peak oxygen uptake. For the remaining 10h, subjects remained seated. The SWA showed significant intraclass correlations between the 2days of testing for the overall 13h of direct supervision (r = 0.97; p< 0.001), the lying awake rest (r = 0.98; p< 0.001), the structured sedentary activity (r = 0.62; p< 0.05), the walking circuit (r = 0.95; p< 0.001), and the standardized physical activity (r = 0.85; p< 0.001). The results of this study indicate that the SWA is a reliable tool to estimate EE during multiple activities. These data provide additional evidence of the usefulness of the SWA in monitoring EE in healthy adults.

PL-127 Assessment of energy expenditure before and after bariatric surgery

With dietary weight loss, a reduction in resting energy expenditure (REE) greater than can be accounted for by changes in body composition is believed to contribute, in part, to weight regain. Experimental animal studies find that Roux-en-Y gastric bypass (RYGB) results in an increase in REE and oxygen consumption (VO2) when expressed per kg of body weight. In this study, we have examined in a clinical fashion the effects of RYGB on REE and VO2 in RYGB patients.

Evaluation of Exercise Intensity and Energy Expenditure of Wii Fit Games

The increasing trend of obesity and participation in daily gaming and technology use has lead the video gaming industry to develop new ways for individuals to become physically active. Previous research has reported that Wii Fit meets minimal criteria for exercise intensity, but this research did not analyze individual game choice or physiological data. PURPOSE: To examine selection rate and physiological demand of individual Wii Fit activities during 30 minutes of Wii Fit play. METHODS: Twelve healthy, physically active females (21 ±1.6 years, 65.9 ±16.9 kg, 1.68 ±0.08 m, 41.2 ±7.1 ml/kg/min) completed a graded exercise test to determine level of cardiovascular fitness (VO2max) and maximum heart rate (HRmax). Following two orientation trials, participants completed 30 minutes of self-selected cardiovascular activity using the Wii Fit to assess energy expenditure, VO2, HR, rate of perceived exertion (RPE), and duration. RESULTS: Of the seven activities selected, Basic Run was significantly greater in %VO2max for all activities. Basic Run also demonstrated higher caloric utilization and absolute VO2 compared to all activities except Rhythm Boxing. Hula Hoop and Basic Step both displayed shorter game duration, 1.2 ± 0.1 and 2.1 ± 0.7 minutes respectively, and the lowest RPE scores, 7.6 ± 3.1 and 7.4 ± 2.5 respectively. Boxing was the only activity with significantly higher RPE scores, 15.0 ± 1.4. CONCLUSIONS: The increased metabolic load resulting from the Basic Run was likely a result of the increased total body movement required to run in place. Hula Hoop and Basic Step typically had the lowest values for almost all of the physiological variables. This was most likely due to the short duration of the game, resulting in less actual activity performed. Boxing was the only activity that resulted in a significantly higher RPE, despite lack of significant differences in metabolic variables. Perhaps this increased RPE is a result of the increased use of upper body musculature and the need for more powerful movements with the arms. These results suggest that interactive gaming may be used as a starting point or supplement for physical activity, but one should be mindful to select an activity that requires significant upper and lower body movement to increase intensity and energy expenditure.

Physical Activity Energy Expenditure Of Healthy Elderly People: Relationship With Diet And Anthropometric Variables

PURPOSE: to investigate the relationship among physical activity level, food intake and anthropometric variables of a group of healthy elderly people. METHODS: 99 elderly subjects, both genders were evaluated for: a-) physical activity diary, calculated for daily energy expenditure (EE), according to 9 (CAT 1-9) categories (Bouchard et al,1983); -24-h food recall (calculated for energy (EI), macronutrients, calcium and vitamin D); b-) weight (W), height (H), arm circumference (AC), tricipital skin folder (TS), waist circumference (WC) and calf circumference (CC); body mass index (BMI), arm muscle area (AMA), arm fat area (AFA). The data were analysed by regression and correlation analysis, considering p<0.05. MAIN RESULTS: mean percentage of contribution of each category of physical activity: CAT1= 24.0%, CAT2=30.8%, CAT3=14.7%; CAT4=15.1%, CAT5=14.5%, CAT6= 0.5%, CAT7=0.0%, CAT8=0.3%, CAT9= 0.0%. CAT 1-5 accounted for 21% of CC (R2= 0.21; p=0.01), however after colinearity exclusion (forward stepwise), only CAT1 (R2=0.07; p<0.00) and CAT3 (R2=0.6; p<0.00) presented significance. CAT 1-5 accounted for 50% of AMA (R2= 0.50; p<0.00), without colinearity exclusion. EE significantly correlated with CC (r=0.40; p<0.05) and with AMA (r=0.63; p<0.05). In addition, EE significantly correlated with AFA (r=0.55). Protein intake relative to body weight negatively correlated with all anthropometric variables (BMI: r= -0.38; AMA: r= -0.24; AFA: r= -0.27; EE: r= -0.34; EI: r= -0.34). Daily protein intake was 0.95± 0.54 g/Kg body weight/day; EI was 20.4±10.6 Kcal/kg body weight/day. Calcium intake was low for all individuals (519.7± 285.9 mg/day, against a recommendation of 1000mg/day). Calcium intake correlated positively with CC (r=0.21). CONCLUSIONS: Physical activity showed significant relationship with both lean mass and fat mass, despite of the intensity, which reinforces the important role of physical activity on body mass preventing frailty and the related chronic and acute illnesses. Protein intake seems to confirm the "protective factor" related to excess body weight. Reference: Bouchard C, Tremblay A, Leblanc C, Lortie G, Savard R, Thériault G. A method to assess energy expenditure in children and adults. Am J Clin Nutr 1983; 37:461-7.

Energy Expenditures During Wheelchair Propulsion Derived From A Body-worn Sensor Versus Heart Rate-estimated Equations

The SenseWear™ armband has been shown to be a valid and practical tool to assess energy expenditure (EE) for upright, ambulatory adults. However, we have previously demonstrated that the SenseWear™ armband (AB) overestimated VO2 and energy expenditure compared to indirect calorimetry during different speeds and gradients of treadmill wheelchair propulsion. PURPOSE: This study compared measures of exercise energy expenditure obtained from AB-estimated versus HR-derived VO2 during outdoor, overground wheelchair propulsion. METHODS: Ten individuals with spinal cord injury (SCI) performed overground wheelchair propulsion at a "slow" pace, self-selected pace and "fast" pace over a 746±4 m outdoor test course measured by GPS. EE was estimated concurrently from HR-derived VO2 and the AB. HR-derived VO2 was calculated from each individual's HR-VO2 relationship, measured by indirect calorimetry during 14 different speeds and gradients of treadmill wheelchair propulsion. RESULTS: Across all three paces (n=30), AB and HR-derived VO2 or EE were well correlated (r=0.81, P<0.05). Although AB slightly overestimated mean EE (14.6±4.4 kJ) and VO2 (0.71±0.22 ml·min-1) compared to individually-calculated HR-derived EE (13.9±4.1 kJ) and VO2 (0.67±0.20 ml·min-1), this difference was not significant. However, correlations between AB-estimated versus HR-derived EE and VO2 were poor at the "slow" pace chosen by wheelchair users (r=0.27, P>0.05) and the highest (r=0.85, P<0.05) at their "fast" pace. CONCLUSION: This study revealed that an arm-mounted multi-sensor device developed for upright ambulatory movements adequately estimated energy expenditure compared with HR-derived measures of exercise metabolism during overground wheelchair propulsion. However, when the upper-limb movements were slowest, during the "slow" wheelchair pace, the accuracy of the AB was low, with significant overprediction of exercise EE. If the AB is to be deployed as a component of exercise prescription for SCI individuals, it is necessary to develop wheelchair-specific algorithms for the armband to enhance its accuracy of estimating energy expenditures during wheelchair exercise.

Assessment of habitual physical activity and energy expenditure in dialysis patients and relationships to nutritional parameters

Assessment of physical activity level and of energy expenditure is important in the clinical and nutritional care of dialysis patients, but it is not so easy to accomplish. The SenseWear™ Armband (SWA) is a novel multisensory device that is worn on the upper arm and collects a variety of physiologic data related to physical activity. Thus, duration and intensity of physical activity is recorded and expressed as METs (Metabolic Equivalent Task), and energy expenditure is estimated. The aim of our study was to assess interdialytic spontaneous physical activity in stable chronic hemodialysis (HD) patients and the relation to nutritional status and dietary nutrient intake. In 50 stable patients on maintenance hemodialysis treatment and 33 normal subjects (control group), level of spontaneous physical activity and estimated daily energy expenditure was assessed by SWA and related to biochemistry and anthropometry data, bioelectric impedance vector analysis, and energy and nutrient intake information coming from a 3-day food recall. In respect to controls, HD patients showed lower mean daily METs value (1.3 ± 0.3 vs. 1.5 ± 0.2, p < 0.01), a lower time spent on activities > 3 METs (89 ± 85 vs. 143 ± 104 min/day, p < 0.05), lower number of steps per day (5,584 ± 3,734 vs. 11,735 ± 5,130, p < 0.001), resulting in a lower estimated energy expenditure (2,190 ± 629 vs. 2,462 ± 443 Kcal/day, p < 0.05). 31 out of the 50 HD patients (62%) had a mean daily value < 1.4 METs and hence were defined as sedentary. They differed from the active patients for higher age (63 ± 12 vs. 54 ± 12 y, p < 0.01), lower energy intake (26.1 ± 6.4 vs. 32.4 ± 11.3 Kcal/day, p < 0.05) and lower phase angle (5.5 ± 1.0 vs. 6.3 ± 0.9, p < 0.05). SWA-based estimation of daily energy expenditure was negatively related to age (r = -0.31, p < 0.05), whereas positive relations were observed with BMI (r = 0.51, p < 0.001), phase angle (r = 0.40, p < 0.01), serum phosphate (r = 0.49, p < 0.001) and albumin (r = 0.41, p < 0.01). The mean daily METs values were strongly related to normalized energy intake (r = 0.47, p < 0.001) and also to protein intake (r = 0.33, p < 0.05) and to phase angle (r = 0.38, p < 0.01). Multiple regression analysis showed that energy intake and dietary protein intake were independently related to the intensity of physical activity. Our findings indicate that poor physical activity is highly prevalent in stable dialysis patients even when free from physical or neurological disabilities or severe comorbid conditions. The level and intensity of physical activity is positively related to body composition and to dietary nutrient intake. This confirms the strong interrelationship between exercise and nutrition, which in turn are associated with survival, rehabilitation and quality of life in dialysis patients.

Energy expenditure during daily activities as measured by two motion sensors in patients with COPD

In patients with chronic obstructive pulmonary disease (COPD), energy expenditure (EE) assessment during the performance of daily activities is not yet studied in depth. The aim of this study was to determine which daily activities are more demanding to patients with COPD and to compare the accuracy of EE estimation given by the pedometer Digiwalker SW701 (DW) and the multisensor SenseWear Armband (SAB). Thirty-six patients with COPD (20 men; FEV1 48 ± 15%predicted; BMI 25.7 ± 8 kg/m(2)) were submitted to a modified version of the Glittre ADL-test, which included five activities performed for 1 min each: walking on the level, walking on the level carrying a backpack, walking up/downstairs, rising/sitting in chairs and moving objects in and out of a shelf. During the protocol subjects wore both devices concomitantly, and indirect calorimetry (IC) was simultaneously performed as the criterion method to assess EE. The most demanding daily activity for individuals with COPD was walking up/downstairs (4.9 ± 1.7 kcal versus 3.7 ± 1.4 to 4.2 ± 1.8 kcal for the other tasks; p < 0.05). EE estimation by the SAB did not show difference in comparison to IC for the sum of the five activities (SAB = 22.7 ± 7 kcal versus IC = 21 ± 8 kcal; p > 0.05), although overestimation was found in activities involving walking. DW showed significant EE underestimation in the sum of the activities (9.6 ± 4.3 kcal; p < 0.05 versus IC) and for each activity. Walking up/downstairs was the most energy-demanding daily activity for patients with COPD. Furthermore, during daily activities, the multisensor showed adequate overall estimation of energy expenditure, as opposed to the pedometer.

Assessment of Energy Expenditure and Recommendations for Physical Activity using Evidence-Based Guidelines

Assessment of Energy Expenditure and Recommendations for Physical Activity using Evidence-Based Guidelines

Assessment of sleep patterns, energy expenditure and circadian rhythms of skin temperature in patients with acute coronary syndrome.

SummaryBackgroundThere is no simple and practical way to monitor sleep patterns in patients in acute care units. We designed this study to assess sleep patterns, energy expenditure and circadian rhythms of patients’ skin temperature in the coronary care unit (CCU) utilizing a new portable device.Material/MethodsThe SenseWear Armband (SWA) was used to record sleep duration, distribution over 24 hr, energy expenditure and the circadian rhythms of skin temperature in 46 patients with acute coronary syndrome (ACS) for the first 24 hr in the CCU and upon transfer to the ward. An advanced analysis was used to extract and compare data associated with the above variables in the two settings.ResultsPatients in the CCU had a reduced night’s sleep duration (5.6±2.2 hr) with more frequent and significantly shorter night sessions (p=0.015) than patients in the ward. Energy expenditure and METs (metabolic equivalents of a task) were significantly lower in the CCU than in the ward. However, the midline-estimating statistic of rhythm (MESOR) and acrophase for skin temperature did not exhibit any significant difference between the two settings.ConclusionsPatients with ACS have sleep fragmentation and shorter nocturnal sleep duration in the CCU compared to the ward. On the other hand, there was no difference in the circadian rhythms of skin temperature between patients in the CCU and the general wards.

High frequency yoga breathing increases energy ­expenditure from carbohydrates Comment to: Assessment of sleep patterns, energy expenditure and circadian rhythms of skin temperature in patients with acute coronary syndrome Hadil Al Otair, Mustafa Al-shamiri, Mohammed Bahobail, Munir M. Sharif, Ahmed S. BaHammam Med Sci Monit, 2011; 17(7): CR397–403

High frequency yoga breathing increases energy ­expenditure from carbohydrates Comment to: Assessment of sleep patterns, energy expenditure and circadian rhythms of skin temperature in patients with acute coronary syndrome Hadil Al Otair, Mustafa Al-shamiri, Mohammed Bahobail, Munir M. Sharif, Ahmed S. BaHammam Med Sci Monit, 2011; 17(7): CR397–403

Knee arthroplasty: a cross-sectional study assessing energy expenditure and activity

What has been missing from current assessment tools post knee arthroplasty is a means by which a patient's mobility and activity levels can be objectively measured over time in a real world setting. The Intelligent Device for Energy Expenditure and Activity (Minisun, Fresno, USA) (IDEEA) is one such device that meets these criteria. It quantifies activity by measuring energy expenditure and records the type of activity performed. The purposes of this study were to (i) determine if there were differences in energy expenditure in different groups of patients at various time points pre- and post-surgery and (ii) determine the correlations between energy expenditure and each of the subjective International Knee Documentation Committee (IKDC), Oxford and Tegner scoring systems. Sixty-five total knee arthroplasty (TKA) patients were recruited into a cross-sectional study to collect energy expenditure and activity data using the IDEEA. Data were collected preoperatively and post-operatively at 6-week, 3-month, 6-month and 12-month time intervals. Energy expenditure and type of activity did not significantly change over the five recording periods. The patients spent <5% of the recording time walking, stepping or in transitions between movements. Energy expenditure showed a low to moderate correlation with the subjective IKDC, Oxford and Tegner questionnaires. Current evaluation questionnaires may not accurately record activity levels and TKA patients spend less time walking than the normal population. We believe the IDEEA is an effective tool for objectively measuring activity and energy expenditure following knee arthroplasty.

Validation of the SenseWear Armband at high intensity exercise

The SenseWear Armband (SWA) has been shown to be a valid and practical tool to assess energy expenditure during habitual physical activity. However, previous studies have focused on low-to-moderate intensity activities. The purpose of this study was to assess the validity of the SWA during high intensity exercise. Twenty (ten males, ten females) endurance trained subjects, 24.3 (±2.8) years of age, performed three 10-min treadmill runs at 65, 75, and 85% of their VO(2max) each and also ran outside for 30min at their preferred speed. Energy expenditure was measured with the SWA (software version 6.1) and a portable indirect calorimetry system (Jaeger Oxycon Mobile(®)). The SWA showed a ceiling effect around an intensity of ten METs. Since all subjects exceeded that intensity range during the exercise trials, the SWA significantly underestimated energy expenditure at high intensities. The intra-individual correlations between MET values calculated by the SWA and values derived from the Oxycon, however, were significant for all but two subjects (r=0.390-0.933, mean=0.66±0.25). While providing accurate results for energy expenditure during low-to-moderate intensity physical activities, the SWA does not provide accurate estimates of energy expenditure at high intensity levels. The threshold for accurate measurements seems to be around an intensity of ten METs.

Energy Expenditure in Adults With Cerebral Palsy Playing Wii Sports

Hurkmans HL, van den Berg-Emons RJ, Stam HJ. Energy expenditure in adults with cerebral palsy playing Wii Sports. Objective To determine energy expenditure of adults with bilateral spastic cerebral palsy while playing Wii Sports tennis and boxing. Design Cross-sectional study. Setting University medical center. Participants Five men and 3 women with bilateral spastic cerebral palsy and ambulatory ability (Gross Motor Function Classification System level I or II) participated. The mean participant age ± SD was 36±7 years. Exclusion criteria were comorbidities that affected daily physical activity and fitness, contraindications to exercise, or inability to understand study instructions owing to cognitive disorders or language barriers. Intervention Participants played Wii Sports tennis and boxing, each for 15 minutes in random order. Main Outcome Measure By using a portable gas analyzer, we assessed energy expenditure by oxygen uptake (V̇ o 2) while sitting and during Wii Sports game play. Energy expenditure is expressed in metabolic equivalents (METs), which were calculated as V̇ o 2 during Wii Sports play divided by V̇ o 2 during sitting. Results Mean ± SD energy expenditure during Wii Sports game play was 4.5±1.1METs for tennis and 5.0±1.1METs for boxing ( P=.024). All participants attained energy expenditures greater than 3METs, and 2 participants attained energy expenditures greater than 6METs while playing Wii Sports tennis or boxing. Conclusions Both Wii Sports tennis and boxing seem to provide at least moderate-intensity exercise in adults with bilateral spastic cerebral palsy (GMFCS level I or II). These games, therefore, may be useful as treatment to promote more active and healthful lifestyles in these patients. Further research is needed to determine the energy expenditures of other physically disabled patient groups while playing active video games, and to determine the effectiveness of these games in improving health and daily activity levels.

Energy cost and cardiovascular response to upper and lower limb rhythmic exercise with different equipments in normal-weight and severely obese individuals

The purpose of the study was to assess energy expenditure and cardiovascular response to rhythmic activity with 6 machines exercising different arm and leg muscle groups in normal-weight (NW) and obese (OB) individuals. In 16 extremely OB subjects and 15 NW controls, oxygen uptake (VO2), heart rate (HR), blood lactate (LA) concentration and ratings of perceived exertion (RPE) were determined during submaximal rhythmic exercise at different intensities obtained by increasing the frequency of the movement (FOM) with each machine. Peak VO2 (VO2p) for each equipment was determined with incremental tests up to exhaustion, whereas maximal VO2 was estimated at cycle ergometer. Net energy cost (Enet) of exercise increased (p<0.001) for effect of FOM, in both NW and OB with all equipments. Enet was higher in OB than NW during submaximal exercise with Chest/Back, Shoulder Press/Lat Pull, and Leg Press. Higher VO2p were attained with lower limbs than with upper limbs, in both NW (p<0.001) and OB (p<0.001). At the same VO2 (relative to maximal), HR, LA, and RPE were similar in NW and OB but higher during arm than leg activity (p<0.001), while at the same VO2 (relative to VO2p) no difference was detected. Enet of rhythmic exercise is higher in OB than NW with machines requiring wide displacement of large body segments. For both NW and OB, physiological responses and RPE are importantly affected by the relative activation of involved muscles. LA concentration is an important determinant of RPE, independent of the limb in activity.

Systemic energy homeostasis in Huntington's disease patients

BackgroundHuntington's disease (HD) is a hereditary neurodegenerative disorder caused by an increased number of CAG repeats in the HTT gene. Apart from neurological impairment, the disease is also accompanied by...

Assessment of daily energy expenditure in women with Alzheimer disease living in nursing home

Assessment of daily energy expenditure in women with Alzheimer disease living in nursing home

Energy Expenditures during Wheelchair Propulsion Derived from a Body-worn Sensor versus Indirect Calorimetry

The Bodymedia SenseWear armband has been previously shown to be a valid and practical tool to assess energy expenditure (EE) in upright, ambulatory adults. However, wheelchair propulsion is a dissimilar movement pattern to walking, employing both bi-lateral symmetry and a greater vigour of arm motion. PURPOSE: The purpose of this study was to identify relationships between energy expenditure (EE) derived from the SenseWear armband versus indirect calorimetry in wheelchair users. METHODS: Ten individuals with spinal cord injury (SCI) performed two different wheelchair treadmill protocols, one with a constant grade (1%) but six different velocities, and the other at a constant velocity (2 km·h-1), but with 6 variable grades. EE was measured concurrently from breath-by-breath indirect calorimetry and the SenseWear armband (AB). To assess internal validity of the AB and its equations employed to transform skin temperature, GSR, heat flux and accelerometry to EE, estimated submaximal EE and VO2 were contrasted using each system. RESULTS: Across all treadmill velocity and gradient combinations (n=140), AB overestimated mean VO2 (681±285 ml·min-1) and mean EE (at 14.3±6. kJ·min-1) compared to indirect calorimetry (VO2=530±176 ml·min-1; EE=11.4±4.0 kJ·min-1 [R2=0.66 and R2=0.62, respectively]). For treadmill tests that employed variable speeds over a flat gradient, R2 between indirect calorimetry and AB VO2 or EE ranged from 0.65-0.82. However, when a constant treadmill velocity was employed with variable gradients, R2 between indirect calorimetry and AB VO2 or EE was much lower, in the range 0.34-0.58. CONCLUSION: This study revealed that an arm-mounted multi-sensor device developed for upright movements overestimated both VO2 and EE compared with indirect calorimetry during wheelchair propulsion. Algorithms utilised by the device apparently overestimated metabolic demand, a finding previously observed utilising other types of accelerometry comparing able-bodied versus SCI individuals. Interestingly, the overestimation and variability was greater when gradient was elevated, than when speed increased. It appears it is necessary to apply wheelchair-specific algorithms to the SenseWear armband to enhance the accuracy of estimating energy expenditure during wheelchair exercise.

Comparison Of Two Portable Devices For Assessing Energy Expenditure During High-intensity Running

One of the main challenges of exercise nutrition is to ensure that athletes keep their energy intake and energy expenditure (EE) within healthy limits. Therefore, correct methods to quantify EE are necessary. Exercise-induced EE can be measured reliably with indirect calorimetry (IC) under laboratory conditions but the quantification of EE in the field is more challenging. Portable devices such as the Sensewear Pro3 armband (SENS; BodySense, USA) and the Actiheart monitor (ACTI; CamNtech, UK) have been designed for simple EE assessment on a daily basis. These devices have been validated in the general population but their performance has not been studied adequately during high-intensity exercise. PURPOSE: To compare energy expenditure measured with SENS and ACTI with an accepted reference method (IC) during high-intensity running. METHODS: Twenty-nine male participants (27.2 ± 1.9 y, 184 ± 7 cm, 79.8 ± 7.6 kg) performed a running test, which started at 2.8 m/s. Every 5 minutes, velocity was increased by 0.4 m/s until 4.8 m/s or voluntary exhaustion. During the test, the participants simultaneously wore SENS and ACTI. IC was performed with a ZAN 600 spirograph (Zan, Germany). RESULTS: EE measured with SENS was moderately correlated with IC values (r = 0.68). For running speeds greater or equal 3.2 m/s EE obtained with SENS was significantly smaller than reference data. The difference increased from 1.0 ± 1.0 METs at 3.2 m/s to 4.8 ± 1.7 METs at 4.8 m/s (p < 0.001). Underestimation was minimal before the test (0.2 ± 0.9 METs) but significant post-exercise (3.7 ± 2.9 METs, p < 0.001). For ACTI, there was also a moderate correlation with IC values (r = 0.77). ACTI underestimated EE between 0.9 ± 1.2 METs (2.8 m/s) and 4.3 ± 1.9 METs (4.8 m/s) and also during rest periods (before: 0.5 ± 0.4 METs, after: 4.1 ± 3.0 METs). The level of underestimation grew significantly with increasing EE (p < 0.001). CONCLUSIONS: Both devices performed similarly during the high-intensity running trial. SENS and ACTI underestimated ExEE and the level of underestimation increased significantly with increasing running velocities. However, the correlation with the IC data indicates that the application of exercise-specific should improve the validity of both devices.