The Effect of 4 Weeks of High-intensity Interval Training on selected Physiological and Metabolic Indices in Active Men

The purpose of the present study was to examine the effects of 4 weeks of high-intensity interval training on selected physiological and metabolic indices in active males. Fourteen active male subjects recruited and randomly assigned into two groups: Experimental (HIT=7) or Control (CON=7) groups. Before and after the training, subjects performed: (1) A progressive exercise test to determine VO2max and peak power output in VO2max (Pmax); (2) A time to exhaustion test at Pmax (Tmax); 3) 3 consecutive Wingate tests with 4-min recovery between each. Additionally, resting blood lactate (BLa־), 3 and 20 min after the last Wingate test were measured. HIT group performed high-intensity interval training protocol consisted of 6-10 30-s bouts at 125% Pmax with 4 min of recovery between each, 3 sessions per week for 4 weeks, while CON group did not perform any training programs. All data were analyzed using independent t-test, paired t-test, and analysis of variance with repeated measures at the level of significance of P < 0. 05. After the training, HIT group showed significant improvements in VO2max, Pmax, Tmax, total work in Tmax test (WTmax), Peak power output (PPO) and mean power output (MPO). Furthermore, peak BLa and BLa in recovery were increased and decreased significantly, respectively in HIT group (P < 0. 05). None of the variables was changed in CON group after the training (P > 0. 05). Present findings suggest that short-term high-intensity interval training program with short recovery is highly efficient that can increase both aerobic and anaerobic performances.