The purpose of this study was to investigate the effects of different types of exercise training on neurodegeneration and cognitive function in mice with impaired glucose tolerance (IGT). Thirty-six male C57BL/6 mice were randomly assigned to the control (CO, n = 9) and impaired glucose tolerance (IGT, n = 27) groups. The IGT group consumed 45% high fat diet for 4 weeks and received 40 mg/kg of streptozotocin twice in the lower abdomen to induce IGT. After the IGT induction period, the IGT group was subdivided into IGT + sedentary (IGT, n = 9), IGT + endurance exercise (IGTE, n = 9), and IGT + resistance exercise (IGTR, n = 9). The IGTE and IGTR groups performed treadmill and ladder climbing exercises 5 times per week for 8 weeks, respectively. Fasting glucose and glycated hemoglobin (HbA1c) levels were significantly higher in IGT group than in CO, IGTE, and IGTR groups (p < 0.05). HOMA-IR was significantly higher in IGT group than CO group (p < 0.05). Hippocampal catalase (CAT) was significantly lower in IGT group than in CO group (p < 0.05), while beta-amyloid (Aβ) was significantly higher in IGT group than in CO group (p < 0.05). Hippocampal tau was significantly higher in IGT group than in CO, IGTE, and IGTR groups (p < 0.05). The Y-maze test performance for cognitive function was significantly lower in IGT group than in CO, IGTE, and IGTR groups (p <0.05). These results suggest that IGT induces neurodegeneration and negatively affects cognitive function, while regular exercise may be effective in alleviating neurodegeneration and cognitive decline regardless of exercise type.

Abstract
1. Introduction
2. Methods
    2.1. Animals
    2.2. IGT induction and exercise intervention
    2.3. Cognitive function measurement
    2.4. Blood and tissue sampling
    2.5. Blood and tissue protein level analysis
    2.6. Statistical analysis
3. Results
4. Discussion
5. Conclusion
References

• Jinhee Woo(Department of Physical Education, College of Arts and Physical Education, Dong-A University)
• Ki-Ok Shin(Department of Physical Education, College of Arts and Physical Education, Dong-A University)
• Chan-Ho Park(Department of Leisure and Sport, Dong-Eui University)
• Byung-Kon Yoon(Department of Physical Education, Dong-Eui University)
• Do-Yeon Kim(Department of Physical Education, Pusan National University)
• Ju-Yong Bae(Department of Physical Education, College of Arts and Physical Education, Dong-A University)
• Yul-Hyo Lee(Department of Physical Education, College of Arts and Physical Education, Dong-A University)
• Kangeun Ko(Department of Physical Education, College of Arts and Physical Education, Dong-A University)
• Hee-Tae Roh(Department of Physical Education, College of Arts and Physical Education, Dong-A University) Corresponding author