Justin J. Lang

Systematic review of the relationship between 20 m shuttle run performance and health indicators among children and youth

OBJECTIVE This systematic review aimed to summarize research that assessed the associations between 20m shuttle run test (20mSRT) performance and indicators of physiological, psychosocial and cognitive health among school-aged children and youth. DESIGN Systematic review. METHODS Five online databases were used to identify peer-reviewed studies published from 1980 to 2016. Studies were included if they matched these criteria: population (children and youth with a mean age of 5-17 years and/or in Grades 1-12), intervention/exposure (performance on the 20mSRT), and outcomes (health indicators: adiposity, cardiometabolic biomarkers, cognition, mental health, psychosocial health, self-esteem and physical self-perception, quality of life and wellbeing, bone health, musculoskeletal fitness, motor skill development, and injuries and/or harm). Narrative syntheses were applied to describe the results. A lack of homogeneity precluded a meta-analysis approach. RESULTS Overall, 142 studies that determined an association between 20mSRT performance and a health indicator were identified, representing 319,311 children and youth from 32 countries. 20mSRT performance was favourably associated with indicators of adiposity, and some indicators of cardiometabolic, cognitive, and psychosocial health in boys and girls. Fewer studies examined the relationship between 20mSRT performance and measures of quality of life/wellbeing, mental health and motor skill development, and associations were generally inconsistent. The quality of the evidence ranged from very low to moderate across health indicators. CONCLUSION AND IMPLICATIONS These findings support the use of the 20mSRT as a holistic indicator of population health in children and youth.

Sit less, stand more: A randomized point-of-decision prompt intervention to reduce sedentary time.

OBJECTIVE To determine if a point-of-decision prompt (PODP) targeting sedentary behaviour influenced the proportion of standing individuals during presentations at an academic conference. METHODS Twelve, one-hour groups of presentation sessions (Global Summit on the Physical Activity of Children conference, May 2014) were included in this study; half were randomly assigned to the intervention group and half to the control group. The intervention group was exposed to an oral PODP at the beginning and middle of the presentations. Researchers performed three counts: beginning (e.g. first 10min), middle (e.g. 30-40min), and end (e.g. 50-60min); each count included the number of individuals in the audience and the number of standing individuals. RESULTS A significantly larger proportion of individuals chose to stand during intervention group presentations (16.9±2.0%) compared to control group presentations (10.5±1.5%; chi(2)=7.13; p<0.05). CONCLUSIONS This study demonstrated the effectiveness of PODPs at decreasing sedentary behaviour during an academic conference. PODPs are simple, cost-effective interventions that require minimal time commitment, and represent a population health intervention that could reduce sedentary behaviour in a large group setting.