Background: This study aimed to examine changes in serum brain-derived neurotrophic factor (BDNF) concentrations after exhaustive high-intensity intermittent exercise (HIIE) and non-exhaustive HIIE, and to compare the two conditions.
Methods: Eight healthy male college students (age: 22±1 year) participated in exhaustive (sets: 6-7) and non-exhaustive (sets: 5) HIIE. In both conditions, participants repeated sets of 20 seconds of exercise at 170% V̇O<inf>2</inf>max with 10 seconds of rest between sets. Serum BDNF was measured 8 times in each condition: 30 minutes after resting, 10 minutes after sitting, immediately after HIIE, and 5, 10, 30, 60, and 90 minutes after main exercise. Changes in serum BDNF concentrations over time and between measurement points in both conditions were measured using a two-way repeated measures ANOVA.
Results: Serum BDNF concentrations were measured, revealing significant interaction between two factors (conditions and measurement points) (F=3.482, P=0.027). In the exhaustive HIIE, there were significant increases at 5 minutes (P<0.01) and 10 minutes (P<0.01) after exercise compared to after resting. In the non-exhaustive HIIE, there was a significant increase immediately after (P<0.01) and 5 minutes after (P<0.01) exercise compared to resting. Comparison of the serum BDNF concentrations at each measurement point showed a significant difference at 10 minutes after exercise, with significantly higher values for the exhaustive HIIE condition (P<0.01, r=0.60).
Conclusions: Exhaustive and non-exhaustive HIIE are time-efficient exercises that increase serum BDNF concentrations in healthy adults.