Effects of Different High-Intensity Interval Training Regimens on Endurance and Neuroplasticity After Cerebral Ischemia

Background and Purpose: The objective is to compare the effects of high-intensity interval training (HIIT) with long versus short intervals on endurance and motor performance. Their influence on neuroplasticity markers is assessed in the ipsilesional and contralesional cortex and hippocampus since their remodeling could improve functional recovery. Methods: Rats performed work-matched HIIT4 (long intervals: 4 minutes) or HIIT1 (short intervals: 1 minute) on treadmill for 2 weeks following transient middle cerebral artery occlusion. Forelimb grip strength evaluated motor function while incremental exercise tests measured the endurance performance. Key neuroplasticity markers were assessed by Western blot. Results: Both regimens were effective in enhancing both the speed associated with the lactate threshold and maximal speed at D8 and D15. Neuroplasticity markers were upregulated in the contralesional hemisphere after training contrary to the ipsilesional side. Grip strength completely recovered but is faster with HIIT4. Conclusions: HIIT with short and long intervals induced early aerobic fitness and grip strength improvements. Our findings revealed that neuroplasticity markers were upregulated in the contralesional cortex and hippocampus to promote functional recovery.