Abstract Physical activity (PA) has a positive effect on risk factors related to cardiometabolic health yet amount of PA and time of onset is unclear. Therefore, we investigated the relationship of PA estimates and cardiometabolic risk factors in a large healthy population of an understudied age group of young adults using a standard gravity-based method on body adiposity and risk markers. In 856 (532 women, 324 men, 32–35 years) subjects we evaluated the association of PA and cardiometabolic risk factors in early adulthood. PA was measured using accelerometers for a period of two weeks. Step counts were divided into light (LPA), moderate (MPA), and vigorous (VPA) intensity classes. Income of the household was 63 446 ± 46 899€ and 57.5% had higher education. Total daily step numbers were 11962.5 ± 5163.2, LPA 5459.6 ± 2986.6, MPA 5932 ± 3404.6, and VPA 572.3 ± 668. Higher total PA volume was associated with lower weight, BMI, % body fat, smaller visceral fat area (VFA) and waist circumference, lower total cholesterol, LDL, and reflection coefficient of the pulse wave. LPA correlated with weight, BMI, waist circumference, total cholesterol, LDL, and central pulse pressure (cPP). Percent body fat (%BF), VFA, total cholesterol, LDL, reflection coefficient, heart minute index, and heart minute volume were significantly associated with MPA and VPA intensity PA volume. Lower PA in early adulthood correlates with increased cardiometabolic risk markers which should be translated into specific recommendations to thrive for a healthier lifestyle to delay and decrease their onset.