While days of reported aerobic exercise participation were significantly associated with lower ferritin in men only, days of reported strength exercise training were not associated with significant changes in ferritin levels in men or women. As ferritin is a protein that stores and transports iron, levels correlate to iron status in the blood. Previous research has shown that high-volume exercise training leads to decreased ferritin levels in male endurance athletes . Although type and duration of exercise determine iron metabolism and blood cell adaptations , it is unclear why aerobic exercise were not associated with ferritin levels in women.