24-h movement guidelines and its association with health-related physical fitness in Brazilian adolescents

Purpose

To examine the link between adherence to 24-h movement guidelines (isolated and combined) and muscular strength, cardiorespiratory fitness, and obesity indicators in Brazilian adolescents.

Methods

Data from 980 adolescents (14–19 years) in Florianópolis, Brazil, were analyzed. The dependent variables were body mass index (BMI), body fat, handgrip strength (HGS), maximal oxygen consumption ($\dot{V}$O_2max). The independent variables were physical activity (PA, IPAQ), screen time (ST), sleep (bedtime, wake-up time). Compliance was calculated for each behavior and combinations. Multiple linear regression models were employed.

Results

Overall compliance: 4.1% (boys), 4.9% (girls). Positive associations were found between PA adherence and HGS/ $\dot{V}$O_2max in both sexes, ST adherence and $\dot{V}$O_2max, and adherence to all three guidelines and $\dot{V}$O_2max. Girls showed positive associations between combined PA ​+ ​sleep adherence and HGS, ST ​+ ​sleep and $\dot{V}$O_2max, and negative associations between adherence to two guidelines and BMI. Boys exhibited a negative association between PA and body fat, positive between ST and HGS, and positive/negative between combined PA ​+ ​ST adherence and HGS/body fat. Moreover, adherence to all three guidelines associated positively with HGS.

Conclusion

Adhering to 24-h movement guidelines, alone or in combination, benefits muscular strength and cardiorespiratory fitness in Brazilian adolescents. However, simultaneous adherence did not correlate with obesity indicators.