Independence and Sex Differences in Physical Activity and Sedentary Behavior Trends from Middle Adolescence to Emerging Adulthood: A Latent Class Growth Curve Analysis

Effects of a physical activity promotion programme on body composition in emerging adults with physical inactivity: a study protocol of a randomised controlled trial

INTRODUCTION

A dramatic decline in physical activity may occur in emerging adulthood because of a major transition over the course of a life. The potential for implementing structured behaviour modification strategies to enhance risk-reducing clinical outcomes is widely recognised. The active participation of clients in the discussion and care process is crucial for optimising intervention outcomes and enhancing individuals' motivation to adopt and maintain healthy behaviours. This study therefore aims to evaluate the effectiveness of a physical activity promotion programme based on the goal attainment theory in relation to emerging adults' body composition, using a face-to-face and e-health blended interventions.

METHODS AND ANALYSIS

A two-arm, double-blind, randomised, controlled study will be conducted in 114 university students aged 18-25 years with physical inactivity. The intervention assignment will be blind to study participants, outcome assessors and study statisticians. A goal achievement theory-based physical activity promotion programme is developed in this study, which is a 16-week, face-to-face and e-health-blended physical activity promotion intervention. After informed consent, participants will be randomly assigned to either a control group or a treatment group before the start of the study. The primary outcome is body composition (ie, skeletal muscle mass, body fat mass, body mass index and body fat percentage). Other outcomes include physical activity level, goal attainment scale scores, exercise self-efficacy and motivation level, which will be assessed during the intervention (every 4 weeks) and at the 1 month follow-up. Continuous variables have means and SD, while categorical variables have frequencies and percentages. Independent-samples t-tests will be used to compare continuous variable changes. χ2 tests will be used to compare categorical variable changes. Based on the baseline scores, analysis of covariance will compare the follow-up results.

ETHICS AND DISSEMINATION

This study was approved by the Ethics Committee of Hangzhou Normal University (ratification date: 14 November 2022, 2022059). The results of the study will be submitted for publication and dissemination in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT05697679.

Physical activity habits and their relationship with sociodemographic factors in Chilean adolescents

Physical activity plays an important role in the well-being and development of adolescents. Physical activity habits expressed in terms of frequency and duration are consistently associated with sociodemographic factors such as age, gender, and socioeconomic status. However, there is less evidence of the relationship between the type and context of physical activity in adolescents. The aim of this article is to analyze physical activity habits and their relationship with sociodemographic factors in Chilean adolescents. The cross-sectional study consisted of 7,263 adolescents aged between 10 and 20 years old, students from both public and private schools in all regions of Chile. Physical activity habits were examined by means of a self-report questionnaire. The age groups were classified according to the three stages of adolescence (early: 10 to 13, middle: 14 to 16, and late: 17 to 20 years old). Socioeconomic level was established based on the school vulnerability index (SVI) of the school attended by each adolescent. In the study it was obvious to the level of physical activity for the adolescents was below the international recommendations. A statistically significant association can also be found between the sociodemographic factors studied and the physical activity habits reported by the young people. The multivariate regression analysis established that the risk of not achieving the physical activity recommendations was 2.8 times higher in females than in males, 2.4 times higher in the older age groups (14–16 and 17–20 years old) compared to the 10–13-year age range and 1.1 times in the medium and high vulnerability groups than in the low socioeconomic vulnerability group. These findings highlight the importance of considering all these factors holistically whenever designing programs or public policies that promote the development of healthy physical activity habits in adolescents.