Danielle Symons Downs, Jennifer S. Savage and Jennifer M. DiNallo
Scant research has examined the determinants of primary exercise dependence symptoms in youth. Study purposes were to examine sex differences across leisure-time exercise behavior, motivation, and primary exercise dependence symptoms in youth and the extent to which exercise behavior and motivation predicted exercise dependence within the Self-Determination Theory framework.
Adolescents (N = 805; mean age = 15 years; 46% girls) completed measures of exercise behavior, motivation, and exercise dependence in health/PE classes.
One-way ANOVA revealed boys scored higher than girls on leisure-time exercise behavior, exercise dependence symptoms, and most of the exercise motivation subscales. Hierarchical regression analyses indicated a) sex, exercise behavior, motivation, and their interaction terms explained 39% of the variance in primary exercise dependence; b) Integrated Regulation and Introjected Regulation were important determinants of exercise dependence; and c) sex moderated the contributions of External Regulation for predicting exercise dependence such that boys in the high and low external regulation groups had higher symptoms than girls in the high and low external regulation groups.
These preliminary findings support the controlled dimensions of Integrated Regulation (boys, girls), Introjected Regulation (boys, girls), and External Regulation (boys only) are important determinants of primary exercise dependence symptoms.
Jennifer M. DiNallo, Danielle Symons Downs and Guy Le Masurier
To effectively promote physical activity (PA) and quantify the effects of PA interventions for pregnant women, PA measurement during pregnancy needs improvement. The purpose of this study was to assess PA monitor output during a controlled, treadmill walking protocol among pregnant women at 20- and 32-weeks gestation.
Women (N = 43) wore an Actigraph accelerometer, NL1000, and Yamax pedometer during a 20-minute treadmill walking test [5-minute periods at 4 different speeds (54, 67, 80, and 94 m·min−1)] at 20- and 32-weeks gestation.
Repeated-measures ANOVAs indicated that Actigraph total counts/minute and minutes of moderate-vigorous PA (MVPA), NL1000 steps and minutes MVPA, and Yamax steps decreased from 20- to 32-weeks gestation (P ≤ .05), while body girth circumference and activity monitor tilt increased (P ≤ .05). Repeated measures ANCOVAs, controlling for changes in body girth and monitor tilt, yielded no significant differences in any outcome measures from 20- to 32-weeks gestation.
Preliminary results suggest physical changes during pregnancy impact activity monitor output in controlled settings. Accurately measuring and statistically controlling for changes in body girth at monitor placement site and monitor tilt may improve the accuracy of activity monitors for use with pregnant populations.
Danielle Symons Downs, Guy C. LeMasurier and Jennifer M. DiNallo
Research examining women’s pregnancy physical activity (PA) behaviors with objective measures is scant. Therefore, 2 studies were conducted to determine the feasibility of pregnant women wearing pedometers and to examine women’s self-reported and objectively measured PA behaviors.
Participants were pregnant women (Study 1 N = 50, Study 2 N = 30) who completed the Leisure-Time Exercise Questionnaire (LTEQ) and wore a Yamax pedometer for 3 consecutive days during free living at 20- and 32-weeks gestation.
As predicted in Study 1, we found (a) 100% participant agreement in wearing the pedometer and (b) LTEQ min and pedometer-determined indices classified 67% to 86% of the participants as insufficiently active at 20-weeks gestation. In Study 2, as hypothesized, (a) mean steps/d, LTEQ total, strenuous, and mild min of PA were positively associated at 20- and 32-weeks gestation; (b) mean steps/d and LTEQ strenuous min significantly declined from 20- to 32-weeks gestation; and (c) more women were classified as sedentary and low active at 32-weeks (73%) compared with 20-weeks gestation (50%).
These findings are consistent with previous epidemiological evidence documenting the decline in women’s PA behaviors across the trimesters. They also illustrate that pedometer-determined indices might be a useful tool facilitating PA adoption and maintenance during pregnancy.