Usefulness of motion sensors to estimate energy expenditure in children and adults: a narrative review of studies using DLW.

This corrects the article DOI: 10.1038/ejcn.2017.2.

Sedentary behavior and compensatory mechanisms in response to different doses of exercise-a randomized controlled trial in overweight and obese adults.

BACKGROUND/OBJECTIVES: To examine compensatory changes in sedentary behavior (SB) and light-intensity physical activities (LIPA) in response to a 22-week exercise training program in overweight/obese adults; and to determine if different forms of exercise training and physical activity recommendations interact with these compensatory changes. SUBJECTS/METHODS: Eighty-nine overweight and obese individuals (body mass index (BMI): 25-34.9 kg/m2, 48% males), aged 18-50 years, were randomized into four intervention groups (strength, endurance, combined strength + endurance and physical activity recommendations) with a 25-30% caloric restriction of total daily energy expenditure for 22 weeks. Energy expenditure was measured by accelerometry before, during and after the program. RESULTS: LIPA increased significantly (P<0.001) after three months and at the end of intervention compared to baseline (pre: 281±9 min; 3 months: 303±9 min; post: 312±8 min). SB percentage decreased by 5.3 at the end of the intervention (P=0.002). No interactions were observed between groups or sexes. Significant correlations were found between SB and body weight, fat mass, android fat mass and lean body mass before and after the intervention (P<0.05). LIPA was also significantly correlated with all these body composition variables in the pre-intervention, but only correlated with body weight at the end of intervention. CONCLUSIONS: There were no compensatory changes after a combined exercise and diet program; where minutes in LIPA increased and %SB decreased after the program, without differences among exercise modes. Greater physical activity levels can contribute to a better percentage and distribution of body tissues.

Usefulness of motion sensors to estimate energy expenditure in children and adults: a narrative review of studies using DLW.

It is well documented that meeting moderate-to-vigorous physical activity guidelines of 150 min per week is protective against chronic disease, and this is likely explained by higher energy expenditure (EE). In opposition, sedentary behavior (low EE) seems to impair health outcomes. There are gold standard methods to measure EE such as the doubly labeled water (DLW) or calorimetry. These methods are highly expensive and rely on complex techniques. Motion sensors present a good alternative to estimate EE and have been validated against these reference methods. This review summarizes findings from previous reviews and the most recently published studies on the validity of different motion sensors to estimate physical activity energy expenditure (PAEE) and total energy expenditure (TEE) against DLW, and whether adding other indicators may improve these estimations in children and adults. Regardless of the recognized validity of motion sensors to estimate PAEE and TEE at the group level, individual bias is very high even when combining biometric or physiological indicators. In children, accelerometers explained 13% of DLW's PAEE variance and 31% of TEE variance. In adults, DLW's explained variance was higher, 29 and 44% for PAEE and TEE, respectively. There is no ideal device, but identifying postures seems to be relevant for both children and adults' PAEE estimates. The variance associated with the number of methodological choices that these devices require invite investigators to work with the raw data in order to standardize all these procedures and potentiate the accelerometer signal-derived information. Models that consider biometric covariates seem only to improve TEE estimations, but adding heart rate enhances PAEE estimations in both children and adults.

Sedentary Bout Durations Are Associated with Abdominal Obesity in Older Adults.

OBJECTIVES: In older adults, sedentary behavior has been positively associated with obesity and impaired metabolic health, additional to low moderate-to-vigorous physical activity (MVPA). Further to the total time spent in sedentary behavior, the manner in which it is accumulated - number of continuous sedentary bouts of different extends - may also be relevant. The association for objectively measured uninterrupted sedentary bouts and respective patterns with abdominal obesity in older adults was examined. DESIGN: Cross-sectional. SETTING: Community-based older people were recruited in each region of Portugal. Data collection was performed between September, 2007 and May, 2009. PARTICIPANTS: 351 older adults (230 women) mean age of 75-years. MEASUREMENTS: Sedentary time was measured by an accelerometer (counts/minute <100), worn during waking hours for four consecutive days. Continuous sedentary bouts of 560 length were treated (counts/minute <100). Abdominal obesity was defined by waist circumference (men>102 cm; women>88 cm). RESULTS: There were positive and escalating linear associations for the continuum of sedentary bouts' lengths with waist circumference. Logistic regression showed that for each additional sedentary bout of 10< min<20 the odds of being abdominally obese increased by 6.8% (OR=1.07, 95% CI: 1.02 - 1.13) up to 48% (OR=1.48, 95% CI: 1.07 - 2.03) for each 1-hour sedentary bout increment, after controlling for age, gender, total sedentary time, MVPA time, total wear time, movement counts within the sedentary bouts, socio-demographic and other behavioral attributes, and medical history. CONCLUSION: These findings indicate positive graded associations for continuous sedentary bouts with abdominal obesity. Public health recommendations regarding breaking up sedentary time more often, potentially avoiding very prolonged bouts of sedentary time, are expected to be relevant for older adults.

Accuracy of a combined heart rate and motion sensor for assessing energy expenditure in free-living adults during a double-blind crossover caffeine trial using doubly labeled water as the reference method.

BACKGROUND/OBJECTIVES: A combined heart rate (HR) and motion sensor (Actiheart) has been proposed as an accurate method for assessing total energy expenditure (TEE) and physical activity energy expenditure (PAEE). However, the extent to which factors such as caffeine may affect the accuracy by which the estimated HR-related PAEE contribution will affect TEE and PAEE estimates is unknown. Therefore, we examined the validity of Actiheart in estimating TEE and PAEE in free-living adults under a caffeine trial compared with doubly labeled water (DLW) as reference criterion. SUBJECTS/METHODS: Using a double-blind crossover trial (Clinicaltrials.gov ID: #NCT01477294) with two conditions (4-day each with a 3-day-washout period), randomly ordered as caffeine (5 mg/kg per day) and placebo (malt-dextrine) intake, TEE was measured by DLW in 17 physically active men (20-38 years) who were non-caffeine users. In each condition, resting energy expenditure (REE) was assessed by indirect calorimetry and PAEE was calculated as (TEE-(REE+0.1 TEE)). Simultaneously, PAEE and TEE were estimated by Actiheart using an individual calibration (ACC+HRstep). RESULTS: Under caffeine, ACC+HRstep explained 76 and 64% of TEE and PAEE from DLW, respectively; corresponding results for the placebo condition were 82 and 66%. No mean bias was found between ACC+HRstep and DLW for TEE (caffeine:-468 kJ per day; placebo:-407 kJ per day), although PAEE was slightly underestimated (caffeine:-856 kJ per day; placebo:-1147 kJ per day). Similar limits of agreement were observed in both conditions ranging from -2066 to 3002 and from -3488 to 1776 kJ per day for TEE and PAEE, respectively. CONCLUSIONS: Regardless of caffeine intake, the combined HR and motion sensor is valid for estimating free-living energy expenditure in a group of healthy men but is less accurate for an individual assessment.