Toddler activity intensity during indoor free-play: stand and watch.

OBJECTIVE: Movement patterns among toddlers (16-36 months) differ from other early developmental periods; toddlers practice coordination, balance, and control. Toddler care environments may afford repetition of these emerging skills. This study examined intensity and type of movements during free-play indoors in child care among toddlers. METHODS: A convenience sample (n, 41; mean, 26.5 months) was observed for intensity of physical activity (PA), motor activity type, activity context, and teacher prompts in center-based care using a modified version of the Observational System for Recording Physical Activity for Children-Preschool. RESULTS: The most frequent PA intensity level was sedentary with limb movement. No significant gender differences emerged. Standing, sitting/squatting, and walking were the most frequent activity types. Dominant activity contexts included fine motor manipulative, self-care, and onlooking. Logistic regression results indicated that onlooking significantly decreased the odds of moderate to vigorous PA. Teachers offered few prompts to increase PA. CONCLUSIONS AND IMPLICATIONS: Toddlers demonstrate predominantly sedentary behaviors during free-play. Further observational research across the entire day is warranted to accurately assess intensity and teacher's support for moderate to vigorous PA.

Identification and validity of accelerometer cut-points for toddlers.

The purpose of this study was to derive ActiGraph cut-points for sedentary (SED), light-intensity physical activity (LPA), and moderate-to-vigorous physical activity (MVPA) in toddlers and evaluate their validity in an independent sample. The predictive validity of established preschool cut-points were also evaluated and compared. Twenty-two toddlers (mean age = 2.1 years ± 0.4 years) wore an ActiGraph accelerometer during a videotaped 20-min play period. Videos were subsequently coded for physical activity (PA) intensity using the modified Children's Activity Rating Scale (CARS). Receiver operating characteristic (ROC) curve analyses were conducted to determine cut-points. Predictive validity was assessed in an independent sample of 18 toddlers (mean age = 2.3 ± 0.4 years). From the ROC curve analyses, the 15-s count ranges corresponding to SED, LPA, and MVPA were 0-48, 49-418, and >418 counts/15 s, respectively. Classification accuracy was fair for the SED threshold (ROC-AUC = 0.74, 95% confidence interval = 0.71-0.76) and excellent for MVPA threshold (ROC-AUC = 0.90, 95% confidence interval = 0.88-0.92). In the cross-validation sample, the toddler cut-point and established preschool cut-points significantly overestimated time spent in SED and underestimated time in spent in LPA. For MVPA, mean differences between observed and predicted values for the toddler and Pate cut-points were not significantly different from zero. In summary, the ActiGraph accelerometer can provide useful group-level estimates of MVPA in toddlers. The results support the use of the Pate cut-point of 420 counts/15 s for MVPA.