Muscles adaptation to aging and training: architectural changes - a randomised trial.

Area of Science:

• Muscle physiology and aging research.
• Exercise science and biomechanics.

Background:

• Aging leads to muscle mass reduction, affecting quadriceps and triceps surae.
• Investigating the impact of aging and resistance training on muscle anatomy.

Purpose of the Study:

• To determine how aging and resistance training influence quadriceps and triceps surae muscle cross-sectional area and volume.
• To compare the effects of moderate and high-load resistance training in older men and moderate-intensity training in younger men.

Main Methods:

• 12-week resistance training intervention with older (55% or 80% 1RM) and younger (55% 1RM) men.
• Standardized training volume across all groups.
• Magnetic resonance imaging (MRI) used to calculate muscle volume from anatomical cross-sectional area and muscle length.

Main Results:

• Older men had greater non-contractile material in triceps surae compared to younger men.
• All training groups (young and old) showed increased quadriceps and triceps surae volumes.
• Moderate-intensity training in older adults yielded comparable gains to high-intensity training and greater gains than in younger adults.

Conclusions:

• Age-related muscle loss is muscle-specific.
• Equivalent training volumes at moderate or high intensities promote muscle hypertrophy in older adults.
• Moderate-intensity resistance exercise can reverse age-related muscle mass decline.