Is Higher Frequency Always Better? The Dose-Response Relationship Between Structured Physical Activity Frequency and Physical Fitness Improvement in Preschool Children.

Significant time × group interactions were found for five of six physical fitness measures in preschool children following a 12-week structured physical activity program.

• 63 children aged 3-6 years participated in a 12-week structured physical training program with 60-minute sessions.
• Significant time × group interactions were found for walking the balance beam, 10 m × 2 shuttle run, tennis throwing, continuous jumping with both feet, and standing long jump (p < 0.05).
• No significant time × group interaction was found for sit-and-reach flexibility.
• A 2 (Time: pre- vs post-intervention) × 4 (Group: L/M/MH/H) repeated-measures ANOVA was used to analyze changes within and between groups.

Children in the high frequency group (≥3 sessions/week) performed significantly better than the low frequency group (≤1 session/week) across all five fitness indicators showing significant interactions.

• The H group (≥3 sessions/week) outperformed the L group (≤1 session/week) across all five indicators: balance beam walk, 10 m × 2 shuttle run, tennis throwing, continuous jumping with both feet, and standing long jump (p < 0.05).
• The H group also outperformed the M group (1-2 sessions/week) in the 10 m × 2 shuttle run, tennis throwing, and standing long jump (p < 0.05).
• Post-hoc analyses were used to identify between-group differences at post-test.

The moderate-to-high frequency group (2-3 sessions/week) demonstrated significantly better performance than the low frequency group in three fitness indicators.

• The MH group (2-3 sessions/week) performed better than the L group (≤1 session/week) in the balance beam walk, 10 m × 2 shuttle run, and tennis throwing (p < 0.05).
• No significant differences were observed between the MH and H groups at post-test, suggesting a performance plateau above 2-3 sessions per week.
• These findings suggest diminishing marginal returns when frequency exceeds three sessions per week.

Participating in structured physical activity fewer than two sessions per week was insufficient to meaningfully enhance physical fitness in preschool children.

• The L group (≤1 session/week) showed significantly worse outcomes than both MH and H groups across multiple fitness measures.
• The M group (1-2 sessions/week) also underperformed compared to the H group in agility (10 m × 2 shuttle run), throwing (tennis throw), and explosive leg strength (standing long jump).
• The findings emphasize the need for at least two weekly sessions of structured physical activity to effectively enhance physical fitness in preschool children.

Sit-and-reach flexibility did not show significant improvement differences between frequency groups over the 12-week intervention.

• No significant time × group interaction was found for sit-and-reach, unlike the other five physical fitness tests.
• This suggests that structured physical activity frequency, as implemented in this program, may not differentially affect flexibility in preschool children.
• The six standardized motor tests assessed balance, agility, throwing, jumping, explosive strength, and flexibility.

The study was designed to examine the dose-response relationship between structured physical activity frequency and fitness improvement in preschool children aged 3-6 years.

• 63 children were divided into four groups based on weekly participation frequency: low (L, ≤1 session/week), moderate (M, 1-2 sessions/week), moderate-to-high (MH, 2-3 sessions/week), and high (H, ≥3 sessions/week).
• Each session lasted 60 minutes and the intervention lasted 12 weeks.
• Physical fitness was assessed before and after the intervention using six standardized motor tests: walking the balance beam, 10 m × 2 shuttle run, tennis throwing, continuous jumping with both feet, standing long jump, and sit-and-reach.