Exercise Oxygen Uptake in 3- through 6-Year-Old Children

Area of Science:

• Pediatric exercise physiology
• Cardiorespiratory fitness assessment in children

Background:

• Assessing maximal oxygen uptake (V̇O₂ max) in young children presents unique methodological challenges.
• Understanding cardiorespiratory fitness in early childhood is crucial for long-term health and athletic potential.

Purpose of the Study:

• To compare submaximal and maximal oxygen uptake between two age groups of young children (3-4 years and 5-6 years).
• To validate age-appropriate methods for eliciting maximal exercise performance in preschoolers.
• To assess walking economy at submaximal exercise intensities.

Main Methods:

• Twenty-two children (ages 3-6 years) participated in progressive treadmill walking tests.
• Criteria for V̇O₂ max determination included oxygen uptake plateau, heart rate > 195 bpm, and respiratory exchange ratio (R) > 1.00.
• Test-retest reliability was evaluated.

Main Results:

• No significant difference in V̇O₂ max was observed between the 3-4 year olds (44.5 ml•kg^-1•min^-1) and 5-6 year olds (44.1 ml•kg^-1•min^-1).
• Children aged 5-6 years exhibited significantly lower relative oxygen uptake at submaximal levels, suggesting enhanced walking economy.
• A high percentage of participants met the established V̇O₂ max criteria, indicating the tests were effective.

Conclusions:

• The developed treadmill protocols are reliable and effective for assessing V̇O₂ max in children as young as 3 years old.
• While maximal aerobic capacity is similar, walking economy improves with age in early childhood.
• These findings provide valuable normative data for pediatric exercise science.