This study examined the potential relationship between participation in physical activity (PA) assessed by triaxial accelerometry and physical fitness testing, including health-related and skill-related parameters of fitness, in 136 Japanese preschoolers (65 girls and 71 boys, 5.5 ± 0.6 years). In partial correlation analyses, grip strength and 20m shuttle run test were positively correlated with time spent in physical activity ratio (PAR) ≥ 4. Better scores on standing long jump distance and jump over and crawl under tests were associated with lower sedentary time and greater moderate-to-vigorous PA time and PAR ≥ 4 time, and increased physical activity level. Moreover, 25m run speed was positively correlated with time spent in PAR ≥ 4 and locomotive activity. These findings suggest that development of both health-related (muscle strength and aerobic fitness) and skill-related fitness (power, agility and speed) may make engagement in PA easier for preschool children, although further research on the cause-effect relationship is needed.
Chiaki Tanaka, Yuki Hikihara, Kazunori Ohkawara, and Shigeho Tanaka
Yuki Hikihara, Shigeho Tanaka, Kazunori Ohkawara, Kazuko Ishikawa-Takata, and Izumi Tabata
The current study evaluated the validity of 3 commercially-available accelerometers to assess metabolic equivalent values (METs) during 12 activities.
Thirty-three men and thirty-two women were enrolled in this study. The subjects performed 5 nonlocomotive activities and 7 locomotive movements. The Douglas bag method was used to gather expired air. The subjects also wore 3 hip accelerometers, a Lifecorder uniaxial accelerometer (LC), and 2 triaxial accelerometers (ActivTracer, AT; Actimarker, AM).
For nonlocomotive activities, the LC largely underestimated METs for all activities (20.3%–55.6%) except for desk work. The AT overestimated METs for desk work (11.3%) and hanging clothes (11.7%), but underestimated for vacuuming (2.3%). The AM underestimated METs for all nonlocomotive activities (8.0%–19.4%) except for hanging clothes (overestimated by 16.7%). The AT and AM errors were significant, but much smaller than the LC errors (23.2% for desk work and –22.3 to –55.6% for the other activities). For locomotive movements, the 3 accelerometers significantly underestimated METs for all activities except for climbing down stairs.
We conclude that there were significant differences for most activities in 3 accelerometers. However, the AT, which uses separate equations for nonlocomotive and locomotive activities, was more accurate for nonlocomotive activities than the LC.