Bone marrow fat fraction assessment in regard to physical activity: KORA FF4-3-T MR imaging in a population-based cohort.

• In our population-based cohort, at least 2 h of physical activity per week were required to show lower levels of bone marrow adipose tissue fat fraction in MRI. • Physical activity seems to affect bone marrow adipose tissue at least preferentially at the spine in contrast to the proximal femur.