Comparison Between the Effect of Mid-Late-Life High-Intensity Interval Training and Continuous Moderate-Intensity...

Area of Science:

• Cardiology
• Gerontology
• Exercise Physiology

Background:

• The effects of exercise on the aging heart are not fully understood, especially concerning high-intensity interval training (HIIT) and continuous moderate-intensity training (CMIT).
• Aging is associated with cardiac dysfunction, structural changes, and altered mitochondrial function.

Purpose of the Study:

• To investigate the impact of 8-week CMIT and HIIT on cardiac function, tissue characteristics, electrical remodeling, and mitochondrial homeostasis in old mice.
• To compare the efficacy of CMIT versus HIIT in mitigating age-related cardiac decline.

Main Methods:

• Old mice were subjected to either CMIT, HIIT, or served as untrained controls for 8 weeks.
• Cardiac function, collagen deposition, neovascularization, aging biomarkers, mitochondrial morphology, and electrical remodeling were assessed.

Main Results:

• HIIT significantly improved survival rates and enhanced cardiac function, collagen deposition, neovascularization, and mitochondrial homeostasis in old mice.
• CMIT alone alleviated age-related cardiac hypertrophy but potentially exacerbated adverse cardiac electrical remodeling.
• HIIT demonstrated broader benefits for the aging heart compared to CMIT.

Conclusions:

• High-intensity interval training (HIIT) offers significant advantages for the aging heart, including improved survival and cardiac function.
• Continuous moderate-intensity training (CMIT) has limited benefits and may pose risks regarding cardiac electrical remodeling.
• HIIT emerges as a potentially superior exercise modality for promoting cardiovascular health in aging populations.