The Effect of High-Intensity Interval Training with and Without Caloric Restriction on Spatial Learning and Long-Term Memory of Obese Rats

Background: Increasing fat mass in the body reduces long-term memory (LTM) and spatial learning (SL). Objectives: The purpose of this study was to compare the effects of high-intensity interval training (HIIT) with and without caloric restriction (CR) on SL and LTM of obese rats. Methods: Forty male Sprague Dawley rats were subjected to a high-fat diet (HFD) for 12 weeks. After confirmation of obesity, they were divided into four groups of 10 subjects, including (1) training (T), (2) training + caloric restriction (T+CR), (3) CR, and (4) obese control (OC). Also, to assess the effect of obesity on the research variables, 10 rats were considered the standard control (SC) group. For 8 weeks, the rats in groups 1 and 2 performed HIIT three times per week at an intensity of 80% to 95% of Vo2max, and groups 2 and 3 received CR of 60%. Results: LTM and SL were significantly decreased by obesity (P = 0.001); T, CR and T + CR had a significant effect on LTM (P = 0.001); T and T + CR caused a significant increase in SL (P = 0.001). However, the CR did not have a significant effect on SL (P = 0.069). Conclusions: It seems that HIIT, and somewhat the CR, by itself has contributed to the improvement of the cognitive impairment of obesity. Also, the interaction of T and CR was effective in improving these disorders, but its effect was not more intense than each one alone.