Purpose: This feasibility study compared the effects of 2 movement programs, traditional and mastery climate (i.e., the Children's Health Activity Motor Program [CHAMP]), on lesson context and children's physical activity (PA) levels. A secondary aim was to examine sex differences in PA levels in both programs. Method: Seventy-two preschoolers served as participants and were assigned to a movement program. Physical activity levels and lesson context were assessed with the System for Observing Fitness Instruction Time. Results: Preschoolers in CHAMP spent more time walking (p < 0.05, d = 3.3), more time in moderate-to-vigorous PA (MVPA; p < 0.05, d = 3.6), and less time standing (p < 0.05, d = 3.8) compared with those in a traditional movement program. Boys in both programs spent less time standing (p < 0.05, d = 4.8) and more time in vigorous activity (p < 0.05, d = 5.8) and MVPA (p < 0.05, d = 4.4) compared with girls. During CHAMP, children spent less time engaged in management and knowledge (p < 0.05, d = 1.4, and p < 0.001, d = 0.9, respectively) and more time in skill practice (p < 0.05, d = 1.5). Conclusion: The findings support that participation in CHAMP elicits more MVPA in preschool-age children compared with a traditional movement program. The Children's Health Activity Motor Program provided children with more class time devoted to skill practice. The program appears to be an innovative approach that is beneficial for PA engagement and could contribute positively to children's health.