Ninth graders' expectancy-value motivation, energy-balance knowledge, and physical activity

With increased obesity rate and decreased physical activity among children and adolescents, it is crucial to provide ample opportunities for them to increase energy expenditure through moderate-to-vigorous physical activity. To help children and adolescents develop and sustain an energy-balanced living through healthy eating and physical activity, it is equally important to nurture their self-initiated motivation and essential knowledge about balancing energy intake and expenditure. Guided by the expectancy-value theory and the conceptual change learning perspective, this descriptive study was aimed to addressing three research questions: (a) To what extent did expectancy-value constructs affect energy-balance knowledge, in-class and after-school physical activity? (b) To what extent did ninth graders correctly construct their mental representations about energy-balance knowledge? And (c) To what extent did their mental representations developed in health education affect physical activity behavior in physical education and after-school hours? A total of 195 ninth grade students studied 14 energy-balance concepts in classroom-based health education classes and participated in daily physical education. Expectancy-value motivation, energy-balance knowledge, inclass physical activity and after-school physical activity were measured using the Expectancy-Value Questionnaire, concept-mapping, accelerometry, and Three-Day Physical Activity Recall Survey. The descriptive statistical analysis, structural equation modeling, and logistic regression analysis revealed that (a) the role of expectancy-value motivation is complex. Four alternative structural equation models differentiated the facilitating roles of expectancy beliefs and intrinsic value toward in-physical education physical activity from the detrimental role of cost perceived in physical education toward after-school physical activity. (b) The students learned the energy-balance knowledge from the same sources but constructed the knowledge in different mental representations. Most of the mental representations were found to be premature. Consistent with the constructivist theory, the finding suggests a low likelihood that the knowledge would play a guiding role in developing energy-balanced living behavior. (c) Energy-balance knowledge learned in health classes without experiencing physical activities was detached from physical activity in physical education and after-school leisure times. Separating energy-balance knowledge from physical activity in the learning process decontextualized the learning experience. The findings call for change in teaching physical activity related health concepts by incorporating them in physical education classes. Overall the findings indicate a need for physical educators to strengthen students' expectancy beliefs for success and intrinsic value in tasks, but minimize their cost perceptions. In addition, curricular reform should target integrating concepts in health with meaningful physical activities to help students develop relational knowing structures that can be used to guide behavior change and/or enhancement.