Fat Mass Is Negatively Associated with Muscle Strength and Jump Test Performance.

Area of Science:

• Gerontology
• Exercise Physiology
• Kinesiology

Background:

• Muscle mass maintenance does not prevent strength loss in aging adults.
• Fat mass may negatively influence the relationship between muscle mass and functional performance.
• The independent impact of fat mass on muscle strength and jump performance in middle-aged and older adults remains unexamined.

Purpose of the Study:

• To investigate the independent associations between fat mass, leg muscle mass, lower extremity muscle strength, and jump test performance.
• To analyze these relationships in adults aged 55-75 years.

Main Methods:

• Cross-sectional study conducted in a university laboratory setting.
• Fifty-nine older adults (27 men, 32 women) aged 55-75 years participated.
• Dual energy X-ray absorptiometry measured fat and leg muscle mass; jump power/height assessed via maximal countermovement jumps; 1-repetition maximum testing for leg press and hip abduction strength.

Main Results:

• In men, higher fat mass was negatively associated with jump height (p=0.047).
• In women, higher fat mass was negatively associated with jump height (p=0.003), leg press strength (p=0.002), and hip abduction strength (p<0.001).
• Leg muscle mass was positively associated with jump power in women only (p=0.047).

Conclusions:

• Fat mass independently and negatively impacts jump test performance in middle-aged and older men and women.
• These findings highlight the clinical importance of considering fat mass in rehabilitating neuromuscular performance.
• Interventions targeting fat mass reduction may be beneficial for enhancing functional capacity in older adults.