Table 1 Overview of study variables

Physical fitness

Aerobic fitness

20 meter multistage shuttle run test (stage)

Intra-uterine growth

Birth weight (SD)

Subject-specific:

• Gender (male/female)

• Age (years)

• Height (cm)

• BMI (kg/m²)

• Gestational age (days)

• Apgar score (score at 5 min)

Muscular strength

Hand grip strength test (kg) Standing Broad Jump test (cm)

Infant growth

Average standardized growth velocity 0-12 months (ΔSDS)

Family-specific:

• Maternal age (years),

• Maternal height (cm)

• Pre-pregnancy BMI (kg/m²),

• Socio-economic status (class)

Physical activity

Moderate to vigorous physical activity

Accelerometry (minutes/day)

PA questionnaire (score)

Sedentary behavior

Sedentary time

Accelerometry (minutes/day)

PA questionnaire (score)