This study evaluated the effect of 8 minutes of HIIT with incremental overload in an AD model.
Forty male Wistar rats were divided into four groups: an untrained Sham group, Sham trained group, Aβ1-42 (Alzheimer\'s) untrained group, and Aβ1-42 (Alzheimer\'s) trained group (n=10 rats per group). Animals underwent stereotactic surgery and received a hippocampal injection of Aβ1-42 or a saline solution. Seven days after surgery, two weeks of treadmill adaptation followed by a maximal running test (MRT) was performed. Then, animals were subjected to eight weeks of HIIT. Rats were sacrificed 24 h after the behavioral tests (open field and Morris water maze), hippocampal tissue was extracted to analyze the redox balance and BDNF/TrkB pathway, and neuritic plaques (NP) were detected by evaluating silver impregnation.
The AD trained group presented a physical capacity amelioration every two weeks and locomotor, learning, and memory improvements (p<0.05). These effects were accompanied by increased CAT and SOD levels, followed by decreased lipid peroxidation (p<0.05). Furthermore, increased activation of the BDNF/TrkB (p<0.05) pathway and decreased NP was observed.
Based on these results, MRT was essential for an excellent chronic training protocol prescription and overload adjustment. Therefore, 8 minutes of HIIT daily for 8 weeks may reduce behavioral deficits by promoting a positive redox balance and increased activity of the BDNF/TrkB pathway that may contribute to NP attenuation.