Impact of short term high-intensity interval training on the aerobic and anaerobic fitness of young male football players in the final stages of rehabilitation

After rehabilitation, it is important for athletes to regain their previous fitness level in order to return to play. In this study, we sought to determine whether short-term HIIT and MICT improve the fitness in young male football players. Our analysis included 50 participants with a mean age of 16.4 +/- 1.3 years (range: 15.5-17.7 years), a mean height of 174.7 +/- 6.2 cm (163.1-191.0 cm), and a mean weight of 65.7 +/- 6.5 kg (48.6- 79.0 kg). Athletes who had almost completed their rehabilitation and were about to return to playing football were classified into high-intensity interval training (HIIT, n = 25) and moderate-intensity continuous training (MICT, n = 25), and underwent a 12-session intervention training program that lasted four weeks. We conducted graded exercise tests, as well as Wingate, isokinetic strength, and Y-balance tests. The MannWhitney test was used for between-group comparisons and Wilcoxon's test was used for comparisons before and after intervention. Volume of oxygen uptake peak, heart rate recovery and anaerobic threshold showed significant improvement in both groups following intervention but were significantly higher in the HIIT group than in the MICT group (p < 0.05). The Wingate anaerobic peak power and fatigue index showed significant increasement in the HIIT and MICT in first and second sets, but only for third set in the HIIT (p < 0.05). HIIT improved isokinetic strength at 60 degrees/s, whereas both training methods provided improvement at 180 degrees/s (p < 0.05). Results arising from the Y-balance test did not improve in either group. In conclusion, short-term HIIT and MICT are effective methods with which to improve fitness in young male football players preparing to return to play after injury. However, HIIT was slightly more effective than MICT in terms of improving aerobic and anaerobic fitness and strength.