Light physical activity of 3 to 4 hours per day may reduce fat mass for young people
Click Here to Manage Email Alerts
Key takeaways:
- Each minute of physical activity performed per day was linked to a decrease in fat mass.
- The duration of light physical activity performed daily dropped from 6 hours at age 11 years to 3 hours at age 24 years.
Adolescents and young adults who exercise for a longer duration per day, even if it is light physical activity, can reduce their fat mass, according to a study published in Nature Communications.
“Optimal physical activity intensity includes both 3 to 4 hours of light physical activity per day and about 50 minutes per day of moderate to vigorous physical activity,” Andrew O. Agbaje, MD, MPH, clinical researcher in the Institute of Public Health and Clinical Nutrition, School of Medicine at University of Eastern Finland, and honorary research fellow at the Children’s Health and Exercise Research Center in the department of public health and sports sciences at the University of Exeter in the U.K., told Healio. “We observed in 6,000 children that sedentary time contributed 7% to 10% of the total fat mass gained during growth from childhood until young adulthood. Light physical activity decreased the overall gain in fat mass by 9.5% to 15%, while moderate to vigorous physical activity decreased fat mass by 0.7% to 1.7%.”
Agbaje and colleagues collected follow-up data from the Avon Longitudinal Study of Parents and Children birth cohort. Sedentary time, light physical activity and moderate to vigorous physical activity were measured through accelerometers. BMI, waist circumference, total fat mass, trunk fat mass, lean mass, glucose, insulin and lipid levels were collected for 6,059 participants during follow-up visits at age 11, 15 and 24 years. All participants had body composition and accelerometer data available during at least one follow-up visit.
Among the study group, sedentary time increased from 6 hours per day at age 11 years to 9 hours per day at age 24 years. Light physical activity decreased from 6 hours per day at age 11 years to 3 hour per day at age 24 years, whereas moderate to vigorous physical activity had a U-shaped increase with participants averaging about 50 minutes per day at age 24 years.
Benefits of light physical activity
In a fully adjusted model, each minute of sedentary time per day was associated with increased BMI (beta = 0.019; 95% CI, 0.014-0.024; P < .001), trunk fat mass (beta = 0.017; 95% CI, 0.012-0.023; P < .001), total fat mass (beta = 0.019; 95% CI, 0.013-0.024; P < .001) and lean mass (beta = 0.033; 95% CI, 0.028-0.038; P < .001), and a decrease in waist circumference (beta = –0.017; 95% CI, –0.022 to –0.012; P < .001).
Each minute per day of light physical activity was linked to a decrease in BMI (beta = –0.03; 95% CI, –0.035 to –0.025; P < .001), waist circumference (beta = –0.036; 95% CI, –0.042 to –0.031; P < .001), trunk fat mass (beta = –0.028; 95% CI, –0.034 to –0.023; P < .001), total fat mass (beta = –0.032; 95% CI, –0.038 to –0.027; P < .001) and lean mass (beta = –0.036; 95% CI, –0.041 to –0.031; P < .001).
Each minute of moderate to vigorous exercise per day was associated with reductions in BMI (beta = –0.01; 95% CI, –0.015 to –0.004; P < .001), trunk fat mass (beta = –0.024; 95% CI, –0.03 to –0.017; P < .001) and total fat mass (beta = –0.027; 95% CI, –0.034 to –0.02; P < .001). Increases in waist circumference (beta = 0.019; 95% CI, 0.014-0.024; P < .001) and lean mass (beta = 0.006; 95% CI, 0-0.011; P = .038) were observed with each minute of moderate to vigorous physical activity per day.
Engaging in more than 60 minutes of moderate to vigorous physical activity per day was associated with greater reductions in BMI (beta = –0.02; 95% CI, –0.036 to –0.005; P = .011), trunk fat mass (beta = –0.097; 95% CI, –0.114 to –0.08; P < .0001) and total fat mass (beta = –0.09; 95% CI, –0.107 to –0.073; P < .0001) and a greater increase in lean mass (beta = 0.017; 95% CI, 0.002-0.032; P = .025) than participating in less than 40 minutes of moderate to vigorous exercise per day.
New recommendations needed
Agbaje said the findings reveal that light physical activity can be beneficial for young people and called for international organizations to adopt recommendations for light physical activity for children and adolescents.
“It is high time the world replaced the mantra of an average of 60 minutes per day of moderate to vigorous exercise with at least 3 to 4 hours per day of light physical activity, such as taking a long walk, since light exercise appears as the antidote to the catastrophic effect of sedentary time in the young population,” Agbaje said.
Agbaje said clinical trials need to be conducted specifically analyzing the effects of 3 to 4 hours of light physical activity per day on fat mass among children and adolescents.
For more information:
Andrew O. Agbaje, MD, MPH, can be reached at andrew.agbaje@uef.fi.
Collapse
Read more about
Click Here to Manage Email Alerts