| Authors & Country | Study Design | Sample | PA Measure | Outcome Measure | Findings |
| US | 1-year longitudinal study examining the relationship between early activity level and personality characteristics | 123 3 yr children (50% boys) | Actometer (2 h per session, 3 - 4 sessions with an interval of 1 week) | Sex, IQ, and personality using the California Child Q Set | The sex difference was inconsistent; boys were significantly more active than girls at age 4, but not at age 3. PA was not related to IQ across ages. Preschool activity level was only related to a set of interpersonal and motoric attributes. |
| | 9-month longitudinal study investigating the relationship of PA with motor skills, aerobic fitness and body fat | 217 4 - 6 yr children (48% boys, mean age = 5.2 yr) | Accelerometer: 10.8 h/d (at least 2 weekdays & 1 weekend day with at least 6 h/d) | Agility: obstacle course Balance: balance beam Aerobic fitness: 20-m shuttle run % body fat: BIA | PA was positively associated with motor skills and aerobic fitness at baseline as well as with the longitudinal changes. Specifically, only VPA was related to changes in aerobic fitness. Higher PA was associated with less %body fat at baseline, but not with its change. Conversely, baseline motor skills, aerobic fitness or %body fat were not related to changes in PA. |
| CA | 15-month longitudinal study investigating the tracking of PA | 17 3 - 5 yr children (59% boys, mean age = 4.4yr, mean BMI = 16.6, 23.5% overweight) | Accelerometer: 10.6 hr/d in ear 1 and 11.6 hr/d in year 2 (at least 5 hr/d, 4 days including at least 1 weekend day) | Age | Total PA was not significantly different between year 1 and 2. MVPA significantly increased at year 2. |
| UK | 3-year longitudinal study examining the relationship between PA and sedentary behaviors | 149 3 - 4 yr children (49% boys, mean age = 4.4yr, mean BMI = 15.5, 37% African American, 37% Anglo-American, 26% Hispanic) | Heart rate monitor (from 7 am to 7 pm with at least 504 min/d, HR >140 bpm as MVPA) Observation using the Child’s Activity Rating Scale | Sex, sedentary behaviors (TV viewing and not TV viewing), and parental encouragement or discouragement for PA | Gender was not a significant predictor. Sedentary behaviors, excluding TV viewing, significantly predicted heart-rate monitored PA. Parental encouragement or discouragement was not a significant predictor of PA. |
| UK | 1-year longitudinal study describing normal developmental changes in PA | 104 3 - 4yr children (50% boys, mean age = 3.7yr, only 60 children re-assessed after one year) | Accelerometer: 10.7 hr/d for 4.1 days (at least 6 hr/d, 3 days including 2 week days and 1 weekend day) | Sex, age, SES, and week days/weekend | At baseline, boys were significantly more active than girls. Children’s PA significantly increased after 1 year. There were not significant differences in activity level associated with SES and between weekday and weekend. BMI was weakly associated with PA. |
| | 1-year longitudinal study examining the influence of season and increasing age on objectively assessed PA and the stability of young children’s PA ranking | 85 3 - 4 yr children (61% boys, only 37 children re-assessed after about one year) | Pedometer: at least 3 weekdays & 1 weekend day with at least 9 h/d) | Seasonal variable (spring and winter), parental duration of daily play with child, neighborhood safety, and the amount of time children spent outdoors | There was no evidence to support a gender difference in the PA levels. There was a substantive difference in the children’s PA between winter and spring. The duration of fathers’ daily play with children was related to winter PA, whereas having a safe place to play was related to spring PA. There is a main effect for year of measurement in weekly, weekday, and weekend PA (PA are greater at the age of 5). |