The authors studied the effects of gamma radiation and submaximal physical exercise on 2,3-DFG content in healthy men erythrocytes. Twelve men aged 20-22 were examined. They were loaded by physical exercise (at doses of 2 M/kg body weight) for 15 minutes. Erythrocytes were exposed to gamma radiation (500 Gy doses) from a 60Co source. The concentration of 2,3-DFG in erythrocytes was estimated by Bartlett's method. Gamma radiation at 500 Gy dose was found to decrease 2,3-DFG content in erythrocytes both at rest and after submaximal exercise. Furthermore, submaximal physical exercise was found to decrease 2,3-DFG content in non-irradiated erythrocytes.