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Effect of Acute Explosive Fatigue Training on Bio-Electric Interferential Currents in Male Sprinters Yajun Tan1, Xingyue Yang1, Jiao Wang1, Yanan Li1, Wanyou Li1, Wenliang Nie2, Liangchou Zou2, Ruibin Ye1, Benxiang He1 1Depts. of Sport Medicine, Chengdu Sport University, Chengdu, China, 2Dept. of Sports and Health, Guangzhou Institute of Physical Education, Guangzhou, China.

Abstract. Objectives: To study the effect of acute explosive fatigue training on bio-electric interferential current (a method to assess the physiological motor and sensory/painful responses to certain stimulations) in male sprinters. Methods: Seventeen elite sprinters (aged 18-22) were measured prior to and immediately after an acute explosive fatigue training session (lasting for 2 hours plus normal training). They were further measured at 24, 48 and 84 hours post training. Bio-electric interferential currents (IC in mA) of the lower legs were assessed at 10 Hz, 50 Hz and 100 Hz frequency by a Frequency Analyzing Method (FAM) device (Juno Oy, Finland) and the results were compared to the heart rate (HR) records measured by Smart HR belt (Suunto Oy) and analyzed by Firstbeat Health software. Results: ICs increased significantly from 25.5±9.1 to 30.8±6.8 (p<0.05) in sensory response at 10 Hz post fatigue training but decreased significantly at 24-hr (<0.05) post-training and retained to pre level thereafter. Motor response trend similar to sensory response but did not reach significant. The changes of ICs in sensory were correlated with the changes of the HR from pre to immediately post training at 10 (r=0.54, p<0.05) and 100 (r=0.65, p<0.05) Hz, while motor at 50 Hz (r=0.55, p<0.05) and the pain response at 100 Hz (r=0.58, p<0.05). Conclusions: The results suggest that FAM is able to distinguish the fatigue during training and recovery.