When does sedentary behavior become sleep? A proposed framework for classifying activity during sleep-wake transitions

The Sedentary Behavior Research Network recently published a consensus definition for sedentary behavior as ‘any waking behavior characterized by an energy expenditure ≤1.5 metabolic equivalents, while in a sitting, reclining, or lying posture.’ While this is a great step toward theoretical and methodological unity, further clarity around issues of classifying sedentary behavior while in bed is needed, specifically during sleep-wake transitions. A thigh-worn inclinometer with a 24-h wear protocol is recommended for best practice assessment of sedentary behavior, but this method introduces challenges for activity classification and data reduction. The constant stream of data collection does not distinguish waking sedentary activities in bed, e.g., watching television or reading, from sleep. Moreover, correct classification during sleep-wake transitions is not well established. Sleep-related behaviors can include time spent trying to fall asleep (sleep onset latency), night awakenings while attempting to fall back asleep (wakefulness after sleep onset), and unsuccessful attempts to fall back asleep in the morning (wakefulness after sleep offset). While these behaviors technically fit into the current definition of sedentary behavior, sleep-related behaviors belong in the sleep domain, are a normal part of the sleep-wake cycle, and are not likely an intervention target for sedentary behavior reduction. For these reasons, we argue that sleep-related behaviors should not be classified as sedentary. The research implications of using this framework for classifying sedentary behavior via 24-h thigh inclinometers include that diaries must ask participants to report the time they got into bed, began attempting to fall asleep (‘lights out’), woke up for the day, and got out of bed for the day. Using these diaries, researchers must manually extract the relevant period of wakefulness (and remove sleep-related and sleep time). The importance of this more burdensome protocol for researchers and participants, and across various subject populations, should be evaluated in future research

Comparing Energy Expenditure During Land and Shallow Water Walking in Overweight and Obese Females

Introduction: The prevalence of overweight and obesity in the United States has reached epidemic levels. Reduction in body weight is of great importance for overweight and obese individuals through the increase in physical activity. One particular mode of physical activity that is currently growing in popularity is shallow water walking, although little research has been done examining the energy cost of this activity in an overweight and obese population. Purpose: To compare the energy expenditure (kcal/min) and rating of perceived exertion (RPE) of a bout shallow water walking at a self-selected pace to a bout of land walking at a matched heart rate response and to a bout of land walking at a self-selected pace in overweight and obese women. Methods: Nineteen participants completed three 10-minute experimental trials including a self-selected pace shallow water walking trial, a matched heart rate response land walking trial, and a self-selected pace land walking trial. Results: Significantly lower energy expenditure (p= 0.046) was observed for shallow water walking (6.46 ± 1.38 kcal/min) compared to the matched heart rate response land walking bout (7.26 ± 1.29 kcal/min), although no significant differences were detected for energy expenditure for shallow water walking and self-selected pace land walking (6.92 ± 1.61 kcal/min). No significant differences were detected for RPE across conditions (p=0.439). Exploratory analyses revealed correlations between measures of body composition (BMI and percent body fat) and the difference in energy expenditure between shallow water walking and matched heart rate response land walking. Conclusions: Findings from the current study suggest that although producing energy expenditure compared to heart rate matched land walking, shallow water walking is a viable alternative that can elicit and increase in energy expenditure performed at a moderate intensity, meeting ACSM criteria. Results of the exploratory analyses revealed an association between measures of body composition and differences in energy expenditure. Although only a limited number of participants of the present study had BMI’s above 35.0 kg/m2 (n=2), findings suggest that water exercise may be an alternative form of exercise and produce higher caloric expenditure at higher ranges of BMI and percent body fat

Energy Expenditure and Enjoyment of Active Television Viewing

International Journal of Exercise Science 9(1): 64-76, 2016. This study examined energy expenditure and enjoyment during sedentary television viewing (SED-TV), stepping in place during television commercials (COMM-TV), and physical activity prompted by common character phrases/mannerisms within a television program (PA-TV). Adults (N=38, age: 27.0±8.0 years, BMI: 25.4±4.2 kg/m2) completed three 30-minute sessions in random order: SED-TV, COMM-TV, and PA-TV. Energy expenditure and heart rate were assessed during each session. Enjoyment was assessed after the initial experimental session and at completion of the study. Energy expenditure was greater in the active versus sedentary sessions (COMM-TV vs SED-TV: difference = 32.7±1.9 kcal, p3.0 METS was lower in SED-TV (median = 0 minutes) compared to COMM-TV [median = 4.0 minutes (Inter-Quartile Range: 0.8, 7.3)] (p50% of age-predicted maximal heart rate. Both COMM-TV and PA-TV were reported to be significantly more enjoyable than SED-TV. COMM-TV and PA-TV resulted in higher energy expenditure, more minutes of moderate intensity physical activity, and higher reported enjoyment compared to SED-TV. These findings have implications for reducing sedentary time during television viewing, which may impact health-related outcomes. Intervention trials are warranted to determine the effectiveness of these strategies

Pilot Feasibility Study of a Campaign Intervention for Weight Loss among Overweight and Obese Adults

Background: Behavioral interventions produce significant short-term weight loss. However, these interventions typically require regular in-person sessions, which may not be feasible for all individuals. Purpose: The purpose of this pilot study was to evaluate the feasibility of a 12-week campaign intervention (CI) compared to a standard on-site, group-based behavioral weight loss intervention (SBWL) among overweight/obese adults. Methods: SBWL participants (n=13; age: 42.5 ± 9.1 years; BMI: 33.4 ± 3.8 kg/m²) attended weekly group meetings, were prescribed a daily reduced caloric goal and 200 minutes of moderate-intensity physical activity per week. CI participants (n=13; age: 43.8 ± 9.0 years; BMI: 33.2 ± 3.8 kg/m²) received the same recommendations as the SBWL, attended in-person group meetings at weeks 0 and 12, and received e-mail messages weeks 2-11. Additional CI features included a thematic framework and an incentive-based point system targeting behavioral goals. Results: Significant weight loss was demonstrated for intention-to-treat (SBWL: -5.6 ± 2.9 kg; CI: -3.1 ± 3.4 kg) (

A Call to Clarify the Intensity and Classification of Standing Behavior

Public health guidelines for physical activity now include recommendations to break up prolonged sitting with light-intensity activities. Concurrently, interventions to increase standing have emerged, especially within the workplace in the form of sit–stand or standing workstations. Moreover, in short-duration studies, breaking up prolonged sitting with standing has been associated improved cardiometabolic outcomes. Publicly available estimates of the intensity of standing range from 1.5 to 2.3 metabolic equivalents (METs), neatly classifying standing as a light-intensity activity (>1.5 to 2.0 METs and ≤2.0 METs, respectively. However, this study reviews data suggesting that some standing (e.g., while performing deskwork) is substantially below the minimum light intensity activity threshold of 1.5 METs. These data bring into question whether standing should be universally classified as a light-intensity behavior. The objectives of this study are to (i) highlight discrepancies in classifying standing behavior in the human movement spectrum continuum, and (ii) to propose a realignment of the ‘active’ vs. ‘passive’ standing threshold to match the light intensity threshold to help provide a clearer research framework and subsequent public health messaging for the expected health benefits from standing.N/

ANDALE Pittsburgh: Results of a Promotoraled, Home-Based Intervention to Promote a Healthy Weight in Latino Preschool Children

Background: Latino preschool children have higher rates of obesity than preschool children from other racial/ ethnic groups; however, few effective, culturally appropriate interventions exist targeting this group. The purpose of this study was to test the feasibility of a 10-week, promotora-mediated, home-based intervention to promote a healthy weight in Latino preschool children. Methods: Trained promotoras (community health workers) delivered 10, 90-min weekly interactive and tailored sessions to Latino families living in Allegheny County. Participants were recruited through promotoras’ own social networks and community gatherings, flyers, and word of mouth. Primary outcome measures included child body mass index (BMI) z-score and percentile. Secondary outcome measures included child objectively measured physical activity and dietary intake, and the home social and physical environment (e.g., parent health behaviors, parent selfefficacy, parental support, physical activity equipment in the home). The final analysis sample included 49 of 51 participants who completed both baseline and follow-up assessments. Results: Participants included mothers (33.5 ± 6.1 years old) and their preschool-aged children who were primarily 1st generation immigrants from Mexico (65%). The primary analyses of BMI percentile and z-score showed no change post-intervention. However, there was a significant decrease in child BMI percentile for overweight and obese children from baseline to follow-up (p \u3c .05). We also saw significant pre/post increases in child daily fruit and vegetable intake, and parent moderate-to-vigorous physical activity, fruit and vegetable servings per day, and self-efficacy; and significant decreases in child saturated fat and added-sugar intake, and child and parent screen time (p’s \u3c .05). Conclusions: Despite the short duration of the intervention and follow-up, this pilot study showed promising effects of a promotora-mediated intervention to promote a healthy weight in Latino preschool childre

Reliability of pulse waveform separation analysis: effects of posture and fasting

Objective: Oscillometric pulse wave analysis devices enable, with relative simplicity and objectivity, the measurement of central hemodynamic parameters. The important parameters are central blood pressures and indices of arterial wave reflection, including wave separation analysis (backward pressure component P b and reflection magnitude). This study sought to determine whether the measurement precision (between-day reliability) of P b and reflection magnitude: exceeds the criterion for acceptable reliability; and is affected by posture (supine, seated) and fasting state. Methods: Twenty healthy adults (50% female, 27.9 years, 24.2 kg/m2) were tested on six different mornings: 3 days fasted, 3 days nonfasted condition. On each occasion, participants were tested in supine and seated postures. Oscillometric pressure waveforms were recorded on the left upper arm. Results: The criterion intra-class correlation coefficient value of 0.75 was exceeded for P b (0.76) and reflection magnitude (0.77) when participants were assessed under the combined supine-fasted condition. The intra-class correlation coefficient was lowest for P b in seated-nonfasted condition (0.57), and lowest for reflection magnitude in the seated-fasted condition (0.56). For P b, the smallest detectible change that must be exceeded in order for a significant change to occur in an individual was 2.5 mmHg, and for reflection magnitude, the smallest detectable change was 8.5%. Conclusion: Assessments of P b and reflection magnitude are as follows: exceed the criterion for acceptable reliability; and are most reliable when participants are fasted in a supine position. The demonstrated reliability suggests sufficient precision to detect clinically meaningful changes in reflection magnitude and Pb

The Relationship Between Daytime Sedentary Behavior and Sleep Health in Desk-based Workers

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COVID-19 Impact on Behaviors across the 24-Hour Day in Children and Adolescents: Physical Activity, Sedentary Behavior, and Sleep

In the wake of the COVID-19 pandemic, social restrictions to contain the spread of the virus have disrupted behaviors across the 24-h day including physical activity, sedentary behavior, and sleep among children (5–12 years old) and adolescents (13–17 years old). Preliminary evidence reports significant decreases in physical activity, increases in sedentary behavior, and disrupted sleep schedules/sleep quality in children and adolescents. This commentary discusses the impact of COVID-19-related restrictions on behaviors across the 24-h day in children and adolescents. Furthermore, we suggest recommendations through the lens of a socio-ecological model to provide strategies for lasting behavior change to insure the health and well-being of children and adolescents during the COVID-19 pandemic

Estimating physical activity in children aged 8-11 years using accelerometry: contributions from fundamental movement skills and different accelerometer placements.

Accelerometers are widely used to assess physical activity, but it is unclear how effective accelerometers are in capturing fundamental movement skills in children. This study examined the energy expenditure during different physical activities (PA) and calibrated triaxial accelerometry, worn at the wrist, waist and ankle, during children’s PA with attention to object control movement skills and cycling. Thirty children (14 girls) aged 8 to 11 years wore a GENEActiv accelerometer on their non-dominant wrist, dominant wrist, waist and ankle. Children undertook eight, 5-min bouts of activity comprising being lay supine, playing with Lego, slow walking, medium walking, medium paced running, overarm throwing and catching, instep passing a football and cycling at 35 W. VO2 was assessed concurrently using indirect calorimetry. Indirect calorimetry indicated that being lay supine and playing with Lego were classified as sedentary in nature (3 METs). ROC curve analysis indicated that discrimination of sedentary activity was excellent for all placements although the ankle performed better than other locations. This pattern was replicated for moderate physical activity (MPA) where the ankle performed better than other locations. Data were reanalyzed removing cycling from the data set. When this analysis was undertaken discrimination of sedentary activity remained excellent for all locations. For MPA discrimination of activity was considered good for waist and ankle placement and fair for placement on either wrist. The current study is the first to quantify energy expenditure in object control fundamental movement skills via indirect calorimetry in children aged 8–11 years whilst also calibrating GENEActiv accelerometers worn at four body locations. Results suggest throwing and catching is categorized as light intensity and instep kicking a football moderate intensity, resulting in energy expenditure equivalent to slow or medium paced walking or cycling and running, respectively. Ankle worn accelerometry appears to provide the most suitable wear location to quantify MPA including ambulatory activity, object control skills and cycling, in children aged 8–11 years.N/