Determining the reliability and validity of two measures of lower body muscular fitness for adolescents

NAME: Test-retest reliability of the 30-second sit-to-stand squat test as a measure of lower body muscular fitness. WHY: To determine if the 30-second sit-to-stand squat test could be used as a reliable field-based test when assessing adolescents' lower body muscular fitness. WHAT: Participants completed the assessments on two occasions separated by 1 week. On each occasion, students completed the 30-second sit-to-stand test, the standing long jump test, and anthropometric tests of height and weight. WHO: Five trained research assistants completed all assessments and measurements were undertaken using the same instruments on each occasion. HOW: Anthropometric evaluations of height, weight and lower leg length were completed first, followed by participation in the sit to stand test and standing long jump. Height was measured to the nearest 0.1cm using a portable stadiometer Body mass was measured in light clothing without shoes using a portable digital scale to the nearest 0.1kg. Students were blinded to this procedure, standing on the scales backwards with the digital display only viewable by the research assistant. Lower leg length was measured using a ruler from the heel to the popliteal crease behind the student's knee. At no stage where any of the researchers physically touching the participants. All measurements were taken using a ruler and a flat stick to align the measurement with the popliteal crease. The standing long jump test is administered outdoors on a flat, dry grass surface. Participants begin with their toes behind a line marked at 0 cm and perform a maximal long jump, taking off and landing with two feet. The test was performed twice, separated by a rest period of at least 15 seconds. The 30-second sit-to-stand test requires participants to complete as many squats as possible in 30 seconds, each time touching the bench of height 44cm at the end of the squat. HOW: On each occasion, researchers made assessments in a face-to-face mode. The duration of each testing session was approximately 2 hours. The total duration of the study was 7 days. Students were assessed one on one at each of the four tests (Height, weight, sit-to-stand test and standing long jump) WHERE: The tests were administered prior to students’ participation in their allocated school sport time allowing for consistency of time and venue. It was an outdoor venue with an undercover flat area available for height and weight.