Elevated energy coupling and aerobic capacity improves exercise performance in endurance-trained elderly subjects

Area of Science:

• Exercise Physiology
• Gerontology
• Mitochondrial Biology

Background:

• Endurance training (ET) enhances maximal oxygen uptake (V(O(2)max)), mitochondrial capacity, and energy coupling efficiency in adults.
• The impact of ET on leg exercise performance (P(max)) and its relationship with physiological improvements in the elderly remains less understood.

Purpose of the Study:

• To investigate whether leg exercise performance reflects improvements in V(O(2)max), mitochondrial capacity, and energy coupling efficiency following ET in elderly individuals.
• To determine the effects of a 6-month ET program on P(max), V(O(2)max), and energy coupling efficiency in older adults.

Main Methods:

• A 6-month endurance training program was administered to 13 elderly subjects (mean age 69.5 years).
• Measurements included leg power output at V(O(2)max) (P(max)), maximal oxygen uptake (V(O(2)max)), and oxygen uptake relative to resting levels (ΔV(O(2)m-r)).
• Energy coupling efficiency was assessed using the ratio of P(max) to ΔV(O(2)m-r) and delta efficiency during submaximal exercise.

Main Results:

• Endurance training significantly improved P(max) (17%), V(O(2)max) (5.4%), and ΔV(O(2)m-r) (9%) in elderly subjects.
• Evidence of improved energy coupling was observed through elevated leg power output per unit V(O(2)) at aerobic capacity and enhanced delta efficiency during submaximal exercise.
• Improvements in P(max) correlated with enhanced muscle oxidative phosphorylation capacity (ATP(max)) and mitochondrial energy coupling.

Conclusions:

• Leg exercise performance in the elderly significantly benefits from endurance training.
• Improvements in energy coupling and oxidative phosphorylation capacity at both whole-body and muscle levels contribute to enhanced exercise performance in older adults.
• Endurance training is an effective intervention for improving physiological function and exercise capacity in the aging population.