ACS examined the potential influence of intermittent physical activity breaks of various intensities (control, light, moderate, vigorous) on measures of immediate mental performance, mood, hunger and several metabolic outcomes in children aged 7-11 years. We build upon previous work to hypothesize that higher-intensity intermittent physical activity breaks throughout an 8-hour day will improve immediate mental performance, mood, and post-exercise physical activity levels, while reducing hunger and post-exercise food intake.
Background: A range of metabolic, behavioral, mental and physical health benefits of regular physical activity have been documented in adults and children in the long-term. Yet, relatively little is known about how children's usual daily physical activity patterns (i.e. small bursts throughout the day) affect acute (immediately post-activity) and short-term (72 hours post-activity) metabolic and psychosocial outcomes. Additionally, little is known how this specific pattern of physical activity affects subsequent physical activity levels (i.e. compensatory behavior) and subsequent dietary intake, over the short-term- information critical to designing effective interventions involving the physical environment of the school classroom. Overall Goal: Active Class Space (ACS) will examine the potential influence of intermittent physical activity breaks of various intensities (control, light, moderate, vigorous) on measures of immediate mental performance, mood, hunger and several metabolic outcomes in children aged 7-11 years. We build upon previous work to hypothesize that higher-intensity intermittent physical activity breaks throughout an 8-hour day will improve immediate mental performance, mood, and post-exercise physical activity levels, while reducing hunger and post-exercise food intake. Specific Aims: (1) To determine the effects of intermittent physical activity breaks of varying intensities on immediate mental performance, hunger and satiety; (2) To determine the effects of intermittent activity breaks of varying intensities on ratings of perceived exertion (RPE), perceived exercise enjoyment, in-task mood, post-exercise food intake and post-exercise physical activity levels; and (3) To examine gender differences in the preceding variables in response to low-, moderate, and high-intensity intermittent physical activity. Design: Eighteen healthy males and twenty-one healthy females between the ages of 7-11 years completed completed four experimental conditions in random order: (1) 8 hours of sitting interrupted with 2--minute, light--intensity activity breaks performed at 25% of heart rate reserve (HRR) every 18 minutes; (2) 8 hours of sitting interrupted with 2--minute, moderate--intensity activity breaks (50% HRR); (3) 8 hours of sitting interrupted with 2--minute, high--intensity activity breaks (75% HRR); and (4) 8 hours of sitting interrupted with 2 minutes of sedentary screen time. Standardized meals will be provided during each experimental condition. Dietary intake and physical activity levels were monitored for the remainder of the experimental day and over the subsequent three days for each condition. Dependent Variables: Major outcome variables include: Energy expenditure measured by indirect calorimetry and heart rate; dietary intake measured using a 3-day dietary record; physical activity measured by accelerometry; immediate mental performance assessed using a 90-sec mathematical computation test; hunger and satiety assessed using a visual analog scale; RPE assessed using the Borg scale; perceived exercise enjoyment assessed using the physical activity enjoyment scale (PACES); in-task mood assessed using the Feeling Scale (FS) and Subjective Exercise Experiences Scale (SEES). Data Analysis: A linear mixed model will be fitted for each outcome variable with effects for condition, sex, BMI, and baseline physical activity level. A Bonferroni correction will be used to adjust for multiple comparisons in post hoc tests following the mixed-effect model. A similar linear mixed-model for raw levels of each outcome variable over time will also be fitted to assess temporal differences between conditions. This model will include effects for condition, time, time-by-condition interaction, sex, BMI, and baseline physical activity levels. Significance: ACS will shed new light on the short-term metabolic, behavioral, mental and physical health benefits of intermittent physical activity breaks in children. The results from this study will inform the design of behavioral and environmental interventions to promote physical activity and cognitive development in pediatric populations.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
SINGLE
Enrollment
39
The light-intensity condition consisted of 8 hours of sitting interrupted with 2--minute, light--intensity activity breaks performed at 25% of heart rate reserve (HRR) every 18 minutes. Standardized meals were provided.
The moderate-intensity condition consisted of 8 hours of sitting interrupted with 2--minute, moderate-intensity activity breaks performed at 50% of heart rate reserve (HRR) every 18 minutes. Standardized meals were provided.
The high-intensity condition consisted of 8 hours of sitting interrupted with 2--minute, vigorous-intensity activity breaks performed at 75% of heart rate reserve (HRR) every 18 minutes. Standardized meals were provided.
Childhood Disparities Research Laboratory
Ann Arbor, Michigan, United States
Physical activity energy expenditure
Physical activity energy expenditure throughout the condition day and over the next three days. Participants wore an accelerometer for four days. Energy expenditure was calculated from accelerometer data.
Time frame: 4 days
40-item immediate mental performance math test
Number of math questions answered correctly within 90 seconds in the morning (800hr), midday (1200hr) and afternoon (1600hr). Scores were marked as number correct out of 40.
Time frame: 1 day
Dietary intake
Standardized meals were provided in the morning, midday and evening and 3-day dietary records were collected three days post-condition day. Total daily dietary intake was calculated from food consumed in the lab and at home.
Time frame: 4 days
Physical activity minutes
Physical activity minutes throughout the condition day and over the next three days. Participants wore an accelerometer for four days. Minutes participating in physical activity was calculated using accelerometer data.
Time frame: 4 days
4-item hunger and satiety visual analog scale
Self reported hunger and satiety in the morning (800hr), midday (1200hr) and afternoon (1600hr). Scores were calculated from a visual analog scale ranging from 0-100 (0= hungry; 0=full), yielding a total between 0- 400
Time frame: 1 day
Single-item ratings of perceived exertion
Perceived exertion during 20, 2-minute activity or sedentary breaks. This single item questionnaire is scored 6-20 (6 = light exertion; 20 maximal exertion).
Time frame: 1 day
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.
The sedentary condition consisted of 8 hours of sitting interrupted with 2-minutes of screen time every 18 minutes. Standardized meals were provided.
Single-item feeling scale
Participants self-reported how they felt during each 20, 2-minute activity or sedentary breaks. This single item questionnaire is scored -5 to +5 (-5 = very bad; +5 = very good).
Time frame: 1 day
16-item exercise enjoyment measure
Self-reported mood in the morning (800hr), midday (1200hr) and afternoon (1600hr). The scale is a combination of 16 positive and negative statements. The responses were scored on a 5-point Likert like scale (1= disagree a lot, 5 = agree a lot). Seven of the 16 statements were reverse scored.
Time frame: 1 day
12-item psychological mood measure
Self-reported mood at midday (1200hr) and afternoon (1600hr). A 3 dimensional, 12-item scale designed to measure changes in 3 categories; positive well-being (e.g., i feel terrific), psychological distress (e.g., i feel miserable), and fatigue (e.g., i feel exhausted). For each item participants will be asked to indicate how strongly they are experiencing the feeling state at that time. Items will be scored on a 7-point Likert scale (1 = "not at all," 7 = "very much so"). Each subscale ranges from 4 to 28 with higher scores representing greater fatigue, positive well-being or psychological distress.
Time frame: 1 day