Serum chemistry and hematological adaptations to 6 weeks of moderate to intense resistance training.

This study examined immune cell and blood chemistry changes occurring in trained weightlifters after 1 week of rest followed by 6 weeks of Olympic-style resistance exercise. Blood was drawn weekly after 1 day of rest at the same time and on the same day of the week for 7 weeks. Lymphocyte numbers increased in weeks 5 through 7. Sodium concentration rose above entry levels in week 2, remained elevated, and peaked in week 5. Direct bilirubin dropped below baseline values in the final week. Chloride and alkaline phosphatase concentrations increased as training progressed. Chloride, potassium, albumin, CO(2), and alkaline phosphatase concentrations peaked in weeks 4 through 6. Serum creatinine was elevated in weeks 2 through 5. Data indicate that resistance training induces changes in immune cell count and blood chemistry that remain within, or near, normal clinical values. It appears that resistance training does not induce immunosuppression or negatively affect hepatic or renal function.