Effect of high intensity interval training on 2,3-diphosphoglycerate at rest and after maximal exercise

Summary

The purpose of this study was to examine the effect of intense interval training on erythrocyte 2,3-diphosphoglycerate (2,3-DPG) levels at rest and after maximal exercise. Eight normal men, mean ± SE=24.2±4.3 years, trained 4 days·week⁻¹ for a period of 8 weeks. Each training session consisted of eight maximal 30-s rides on a cycle ergometer, with 4 min active rest between rides. Prior to and after training the subjects performed a maximal 45-s ride on an isokinetic cycle ergometer at 90 rev·min⁻¹ and a graded leg exercise test (GLET) to exhaustion on a cycle ergometer. Blood samples were obtained from an antecubital vein before, during and after the GLET only. Training elicited significant increases in the amount of work done during the 45-s ride (P<0.05), and also in maximal oxygen uptake ($\dot V_{{\text{O}}_{\text{2}} }$ max: Pre=4.01±0.13; Post=4.29±0.07 l·min⁻¹;P<0.05) during exercise and total recovery$\dot V_{{\text{O}}_{\text{2}} }$ (Pre=19.14±0.09; Post=21.45±0.10 l·30 min⁻¹;P<0.05) after the GLET. After training blood lactate was higher, base excess lower and pH lower during and following the GLET (P<0.05 for all variables). Training caused no significant differences in erythrocyte 2,3-DPG levels at rest (Pre=11.8±0.7; Post=12.1±0.7 Μmol·g⁻¹ hemoglobin (Hb);P>0.05), at exhaustion (Pre=12.0±0.8; Post=11.2±0.8 Μmol·g⁻¹ Hb;P>0.05) or during 30 min of recovery from the GLET. Additionally, acute exercise (pre-training GLET) did not effect any change in 2,3-DPG at exhaustion or during recovery from exercise compared to resting values. The higher$\dot V_{{\text{O}}_{\text{2}} }$ max and total recovery$\dot V_{{\text{O}}_{\text{2}} }$ values observed after training appear to be unrelated to 2,3-DPG levels. Under the present conditions, the role, if any, of 2,3-DPG in enhancing tissue oxygenation during increased metabolic demand remains obscure.