For the BPFT, health is based on two general constructs - physiological health and functional health. Physiological health is related to the organic well-being of the individual - like appropriate levels of aerobic functioning or body composition. Functional health is related to the physical capability of the individual - like the ability to perform and sustain physical activities of daily living. Both constructs contribute to one's ability to enjoy life and to withstand challenges, and both provide indices of good health that serve as a basis for health-related physical fitness.