Vascular dysfunction and the age-related decline in critical power

Area of Science:

• Exercise Physiology
• Aging Research
• Vascular Biology

Background:

• Aging is associated with reduced exercise tolerance and critical power (CP).
• The underlying mechanisms, particularly the roles of muscle mass and vascular function, require further investigation.

Purpose of the Study:

• To determine if the age-related decline in CP is independent of muscle mass.
• To investigate the relationship between age-related CP reduction and impaired vascular function.

Main Methods:

• Compared CP and vascular function in 10 older (63.1 ± 2.5 years) and 10 younger (24.4 ± 4.0 years) physically active adults.
• Assessed leg muscle mass, physical activity levels, passive leg movement (PLM) hyperaemia, and leg blood flow during exercise.

Main Results:

• Older adults exhibited ~30% lower mass-specific CP despite similar leg lean mass and physical activity.
• Impaired PLM-induced hyperaemia and reduced leg blood flow/vascular conductance were observed in older adults at various exercise intensities.
• Mass-specific CP strongly correlated with PLM hyperaemia and vascular conductance during exercise.

Conclusions:

• The age-related decline in critical power is not solely due to reduced muscle quantity.
• Impaired vascular function contributes significantly to the decreased muscle quality observed in aging.
• These findings underscore the importance of vascular health in maintaining exercise capacity during aging.