Effects of acute and chronic high-intensity interval training on serum irisin, BDNF and apelin levels in male soccer referees

This study was aimed to investigate the effects of acute and chronic High Intensity Interval Training (HIIT) on Irisin, BDNF (brain -derived neurotrophic factor), and Apelin levels. The study included twenty-one male soccer referees. Blood from the participants was collected at the beginning of study (1. first measurement: baseline value). HIIT was conducted and blood was immediately collected (2. second measurement: acute effect). Next, HIIT was carried out for 20 minutes of 4 days a week in bouts of running (75 meters in 20 seconds) and walking (25 meters in 20 seconds). Blood was collected at the end of 12 weeks (3. third measurement: chronic effect). HIIT was performed and blood was again collected (4. fourth measurement: acute effect after the chronic effect). There was a gradual increase in irisin, BDNF, and apelin levels (p < 0.001). The increase for irisin was 2% in the second measurement, 106% in the third, and 111% in the fourth compared to the first measurement. The increase for BDNF was 39% in the second measurement, 116% in the third, and 133% in the fourth. Apelin levels were increased by 11%, 19% and 28%, respectively. These results demonstrated that irisin and BDNF might increase only in response to chronic HIIT (4 times a week) while apelin levels might change with both acute and chronic HIIT in healthy trained referees.