Running interval training and estimated plasma volume variation.
Abstract
Abstract The effect of endurance interval training (IT) on haematocrit (Ht), haemoglobin (Hb) and estimated plasma volume variation (PVV) in response to maximal exercise was studied in 15 male subjects (21.1±1.1 years, control group (CG) n=6and training group (TG), n=9). Training group participated in interval training 3-times a week for 7-weeks. A maximal graded test (GXT) was performed to determine maximal aerobic power (MAP) and maximal aerobic speed (MAS) both before and after the training program. To determine Ht and Hb and lactate concentrations, blood was collected at rest, at the end of GXT and after 10- and 30-min of recovery. Maximal aerobic power and maximal aerobic speed increased significantly (p<0.05) after training only in training group. Haematocrit determined at rest was significantly lower in training group than control group after the training period (p<0.05). Interval training induced a significant increase of estimated plasma volume variation at rest for training group (p<0.05) whereas there were no changes for control group. Hence, significant relationships were observed after training between plasma volume variation determined at the end of the maximal test and maximal aerobic speed (r= 0.60, p<0.05) and maximal aerobic power (r= 0.76, p<0.05) only for training group. In conclusion, seven weeks of interval training lead to a significant increase in plasma volume that possibly contributed to the observed increase of aerobic fitness (maximal aerobic power and maximal aerobic speed).