José Francisco López‐Gil

Most of the evidence on physical activity for maintaining a healthy weight in adolescents is based solely on aerobic physical activity alone, with little attention given to the muscle strength component. This study aimed to investigate the associations between aerobic activities and muscle‐strengthening activities (MSA) and overweight/obesity among a representative sample of adolescents. Data from the United States‐based Youth Risk Behavior Surveillance System for the 2011–2019 cycle were used in this cross‐sectional study. Adolescents self‐reported their adherence to aerobic and MSA guidelines, as well as their height and weight. Overweight and obesity were defined using the age‐ and sex‐specific criteria of the Centers for Disease Control and Prevention, with a body mass index (BMI) ≥85th and ≥95th percentiles, respectively. We examined the associations between adherence to physical activity guidelines (reference: not meeting either of the physical activity guidelines) and overweight/obesity or obesity using binary logistic regressions. These analyses were adjusted for race/ethnicity, sex, age, screen time, sleep duration, tobacco, alcohol, fruit, vegetables, and soda consumption. A total of 42 829 adolescents (48.98% girls) were included in the study. Of these, 22.23% met both guidelines for physical activity, 30.47% had overweight/obesity, and 14.51% had obesity. Compared with meeting neither guideline, meeting both aerobic and MSA guidelines was associated with lower odds of having overweight/obesity (odds ratio [OR] = 0.64, 95% confidence interval [CI], 0.60 to 0.68) and obesity (OR = 0.52, 95% CI 0.48 to 0.56). These results were consistent across years of assessment, sex, and race/ethnicity. In conclusion, our results highlight the importance of MSA, which is often overlooked in physical activity recommendations in many studies, in combating childhood obesity in the United States.

Background Physical inactivity, excessive sedentary time, and lack of sleep time have been independently associated with lower health‐related physical fitness. However, little is known about the combined association between 24‐h movement guidelines (i.e., physical activity, recreational screen time, and sleep duration) and components of physical fitness. Objective The main aim was to examine the likelihood of having high/very high levels on different components of physical fitness based on meeting with 24‐h movement guidelines. Methods In this cross‐sectional study, 1276 Spanish youths (13.07 ± 0.86; 55.88% boys), aged 11–16 years, completed self‐reported questionnaires on physical activity, recreational screen time, and sleep duration. Physical fitness components were assessed by 20‐m shuttle‐run test, standing long jump test, handgrip strength test, and 4 × 10‐m shuttle‐run test. Meeting 24‐h movement guidelines was defined as: 9–11 h/day (children aged 5–13) or 8–10 h/day (adolescents aged 14–17) of sleep, ≤2 h/day of recreational screen time and at least 60 min/day of moderate‐to‐vigorous physical activity. The probability of having a high/very high score for each physical fitness components (i.e., ≥60th centile according to the normative cut‐off points for European adolescents) in relation to adherence to 24‐h movement guidelines was analyzed using a series of binary logistic regressions. Results Participants who met the three 24‐h movement guidelines were more likely to have high/very high for cardiorespiratory fitness (OR = 3.31; 95% CI: 1.79, 6.14; p < 0.001), standing long jump (OR = 1.91; 95% CI: 1.06, 3.45; p = 0.031), muscular fitness (OR = 2.05; 95% CI: 1.09, 3.86; p = 0.048) and physical fitness (OR = 1.99; 95% CI: 1.08, 3.66; p = 0.012), but not for handgrip strength (OR = 1.15; 95% CI: 0.64, 2.01; p = 0.636) and speed/agility (OR = 1.65; 95% CI: 0.92, 2.96; p = 0.093), compared to those who did not meet all three recommendations. Conclusion Since meeting the three 24‐h movement guidelines increased the likelihood of having higher levels in most physical fitness components, it seems necessary to promote these movement behaviors early in life, as they could serve as a gateway for improving health‐related fitness in future generations.