Developing physical fitness (PF) behaviors early in life enhances physical development and facilitates sustained participation in physical activity and sports across childhood. This study addressed the effect of different teaching approaches on precursors of PF in kindergarten children. A total of 178 children (5.45 ± 0.40 years, female = 92) from 11 classes were organized into three groups. Group 1 (structured activity + free play) and Group 2 (only free play) attended the same playground (PrimoSport0246) for one hour/week for 10 weeks. Group 3 (structured activity + free play in kindergarten) followed their standard physical education curriculum at school. PF tests (standing long jump, medicine ball throw, and 20 m running speed) were administered pre- and post-intervention. Factorial ANOVA was implemented using a percentage change in PF performance (PFC) as the dependent variable, and teaching approaches, gender, and age as factors. Group 1 demonstrated significant improvements in fitness performance compared with Groups 2 and 3. Moderate to large effect sizes (Cohen’sdrange: 0.68–1.40) were noted in both males and females. Six-year-old demonstrated the greatest improvement in composite PFC compared to Groups 2 and 3. A structured teaching plan, even with a limited dose of once per week, supported the development of PF attributes in kindergarteners.