Strength conditioning in older men: skeletal muscle hypertrophy and improved function

Area of Science:

• Gerontology
• Exercise Physiology
• Muscle Biology

Background:

• Aging is associated with sarcopenia and reduced muscle function.
• Strength training is a potential intervention to counteract age-related muscle decline.

Purpose of the Study:

• To investigate the effects of a 12-week strength conditioning program on skeletal muscle function and mass in older men.
• To assess changes in strength, muscle hypertrophy, and protein turnover.

Main Methods:

• Twelve healthy untrained men (60-72 years) underwent a 12-week strength training program (3 days/week, 80% of one repetition maximum).
• Evaluations included one repetition maximum (1 RM) tests, isokinetic dynamometry, computerized tomography (CT) scans, and vastus lateralis muscle biopsies.
• Urinary 3-methyl-L-histidine excretion was measured to assess myofibrillar protein turnover.

Main Results:

• Significant increases in extensor (107.4%) and flexor (226.7%) strength were observed (P < 0.0001).
• Isokinetic peak torque increased at both 60°/s and 240°/s (P < 0.05).
• CT scans revealed increases in total thigh area (4.8%), total muscle area (11.4%), and quadriceps area (9.3%).
• Muscle biopsies showed significant hypertrophy in both type I (33.5%) and type II (27.6%) muscle fibers (P < 0.001).
• Urinary 3-methyl-L-histidine excretion increased by 40.8% (P < 0.05), indicating elevated myofibrillar protein turnover.

Conclusions:

• Strength conditioning effectively enhances muscle strength and mass in older men.
• The observed improvements are linked to significant muscle hypertrophy and increased myofibrillar protein turnover.
• These findings support resistance training as a strategy to improve muscle health in aging populations.