A 10-Year Longitudinal Study of Muscle Morphology and Performance in Masters Sprinters

Area of Science:

• Exercise Physiology
• Gerontology
• Sports Science

Background:

• Aging leads to muscle mass, strength, and power loss.
• Age-related muscle changes in sedentary and endurance-trained older adults are known, but less so in sprint athletes.
• Masters sprinters' training may preserve muscle strength, function, and morphology over time.

Purpose of the Study:

• To investigate age-related changes in muscle morphology, function, and performance in masters sprinters over a 10-year period.
• To determine if masters sprinters maintain muscle characteristics and performance with aging.
• To explore the relationship between training and age-related muscle changes in sprinters.

Main Methods:

• Muscle biopsies (m. vastus lateralis) from 24 masters sprinters (aged 48-85) at baseline and 10 years later.
• Assessed fibre type composition, fibre cross-sectional area (FCSA), and capillarisation via immunofluorescent staining.
• Measured vastus lateralis thickness (ultrasonography), knee extension maximum voluntary contraction (MVC), counter movement jump power, and 60-m sprint times.

Main Results:

• No significant changes in FCSA, fibre type composition, capillarisation, or VL thickness after 10 years.
• Jump power decreased by 9.5% (p < 0.001) due to a 21.0% decrease in knee extension MVC (p < 0.001).
• 60-m sprint time increased by 14.2% (p < 0.001), with greater performance loss in older participants; no changes related to training years or volume.

Conclusions:

• Masters sprinters aged 48-85 maintained muscle histological characteristics over 10 years.
• Training did not offset decrements in sprint performance and power.
• Performance decline was linked to reduced force-generating capacity, not muscle slowing.