We have previously used Control Entropy (CE) analysis of high-resolution accelerometer (HRA) signal to show complexity of gait decreases during exhaustive treadmill running. PURPOSE: To determine if complexity of postural control decreases following fatiguing Wingate exercise using CE of HRA. METHODS: Ten participants (5 M/5 F; 25±3 yr; 169.4±11.7 cm; 79.0±16.9 kg) consented to participation approved by Western Oregon University IRB and completed two trials separated by 2-7 days. Trials consisted of two single-legged balance tests separated by a Wingate anaerobic test (WAnT; PreWant/PostWant), or rest period (PreRest/PostRest). Balance tests consisted of a series of five single-legged stances, separated by 30 s rest, performed while standing on the dominant leg for 15-s with the participant crossing the arms over the chest and flexing the non-dominant knee to 90 degrees. HRA (MicroStrain, VT) were fixed superficial to L3/L4 at the approximate center of mass (COM). Triaxial signals from the HRA were streamed in real time to a base station at a frequency of 625 Hz and then exported to Matlab (Natick, MA) for analysis. COM accelerations were recorded in g's for vertical (VT), medial/lateral (ML), and anterior/posterior (AP). A newly developed statistic (R-test) was applied to group response shapes generated by Karhunen Loeve (KL) analysis modes resulting from Control Entropy (CE) analysis. RESULTS: R-tests showed a significant mean vector difference (p<.05) within conditions, between axes in all cases, except PostWant, indicating the shape of the complexity response was different in these cases. R-test between conditions, within axis, differences were only present in PostWant for AP (p<.05; 2.95 × 10-3) vs. PreWant (2.86× 10-3). T-tests showed a significantly higher overall CE PostWant in VT and ML compared to PreWant and PostRest (p<.0001). PostWant CE was also higher than PostRest in AP (p<.0001). CONCLUSIONS: These data indicate that fatiguing exercise eliminates the differential complexity response of postural control between axes, but increases complexity in all axes compared to the non-fatigued condition. This has implications with regard to the effects of fatigue on strategies of the control system to maintain postural control.