Measuring Exercise Capacity and Physical Function in Adult and Older Mice

Area of Science:

• Gerontology
• Animal Models of Aging
• Muscle Physiology

Background:

• Sarcopenia and frailty contribute to loss of independence in older adults.
• Small animal models are crucial for investigating the molecular mechanisms of decreased physical function.
• Understanding age-related physical decline requires robust assessment tools.

Purpose of the Study:

• To develop and validate a composite Comprehensive Functional Assessment Battery (CFAB) for assessing physical function and exercise capacity in mice.
• To evaluate the CFAB's utility in tracking age-related changes in physical performance.
• To explore the relationship between different parameters associated with sarcopenia using the CFAB.

Main Methods:

• Utilized a battery of well-validated tests including rotarod, grip meter, treadmill, inverted cling, voluntary wheel running, and in vivo contractile physiology.
• Assessed physical function across three age groups of male C57BL/6 mice (6, 24, and 28+ months).
• Developed a composite CFAB score to quantify overall physical function.

Main Results:

• A significant age-related decline (p < .05) was observed in all measured physical function parameters.
• The CFAB score effectively differentiated physical function across age groups.
• The upper quartile of mice demonstrated functional capacity comparable to younger cohorts, highlighting individual variability.

Conclusions:

• The Comprehensive Functional Assessment Battery (CFAB) is a powerful, repeatable, and noninvasive tool for assessing mouse physical function.
• CFAB enables researchers to track performance at the individual mouse level and compare functional capacity across the lifespan.
• This tool will facilitate research into the molecular mechanisms underlying sarcopenia and frailty.