Impact of Fecal Organic Acid Profile Before Training on Athletic Performance Improvement After High-Intensity Interval Training

Purpose: This study sought to investigate the efficacy of Tabata-style high-intensity interval training (T-HIIT) on athletic performance in judoka and to determine the impact of the fecal organic acid profile before training on the improvement of athletic performance. Methods: Twenty males from Aichi University Judo Club (10 high-level competitors and 10 others) were included. Physical fitness tests such as the Uchikomi shuttle run, countermovement jump, squat jump, and chin-ups using a judo uniform were performed before and after T-HIIT. Fecal samples were collected before T-HIIT to measure the fecal concentration of organic acids. The fecal characteristics were categorized using the Bristol Stool Scale. Results: The mean number of repetitions of the Uchikomi shuttle run test significantly increased for all judoka following T-HIIT. However, improvements in other physical fitness tests varied, with some judoka showing improvements while others did not. The changes in countermovement jump (r = −.48, P = .029) and chin-ups using a judo uniform (r = −.45, P = .045) after T-HIIT were significantly negatively correlated with the fecal concentrations of succinic acid before T-HIIT. There was a significant correlation between the Bristol Stool Scale score and fecal concentrations of succinic acid (r = .45, P = .044). Compared with other compounds, the fecal concentrations of acetic acid and propionic acid were significantly greater in high-level competitors, while succinic acid concentrations tended to be lower. Conclusions: T-HIIT effectively improved the specialized endurance of the judoka. Modifying the fecal organic acid profile, especially the fecal succinic acid concentration, may enhance the efficacy of athletic performance improvements achieved by T-HITT.