Effects of resistance exercise on plasma, erythrocyte, and urine Zn

Twelve healthy male volunteers performed two resistance exercise sessions: a moderate resistance (MR) exercise session and a heavy resistance (HR) exercise session. Blood was collected before exercise and 5 min, 30 min, and 24 h after exercise. Urine was collected for 24 h before and 24 h after exercise. Plasma zinc (Zn) was markedly increased both 5 min and 30 min after MR and HR exercise and was returned to control values the next day. Total blood cell (TBC) Zn was decreased 5 min after MR and HR exercise but was not significantly different than control values at 30 min or 24 h. The changes in plasma and TBC Zn after HR exercise were significantly greater than changes after MR exercise. The results of this study are the first to report changes in Zn after resistance exercise. These data agree with previous studies reporting increases in plasma Zn and decreases in erythrocyte Zn after strenuous running, treadmill, or cycle ergometry exercise; however, the magnitude of the changes reported in this study are considerable greater that changes reported these previous studies. These data support suggestions that increases in plasma Zn levels are the result of leakage from the muscles resulting from muscle damage.