The effect of aging on submaximal exercise performance and recovery

Area of Science:

• Exercise Physiology
• Aging Research
• Cardiorespiratory Function

Background:

• Aging impacts physiological responses to exercise, including gas exchange and heart rate.
• Understanding these age-related differences is crucial for exercise prescription and health management in older adults.

Purpose of the Study:

• To compare the upward drift of gas exchange variables and heart rate during submaximal exercise and subsequent recovery between aged and young individuals.
• To investigate the physiological mechanisms underlying observed differences in exercise response and recovery between age groups.

Main Methods:

• Measurements of ventilation (VE), oxygen consumption (VO2), carbon dioxide production (VCO2), and heart rate (HR) during 70% maximal exercise and recovery.
• Comparison of gas exchange and HR data between a group of aged subjects and a group of young subjects with equivalent age-predicted aerobic capacity.

Main Results:

• Aged subjects showed reduced upward drift in VE, VO2, and HR during exercise compared to young subjects.
• Recovery of VE, VCO2, and VO2 was slower in aged subjects.
• Despite slower recovery, VCO2, VO2, and HR returned to similar relative values in both groups by 10 minutes post-exercise, while VE remained elevated in young subjects.

Conclusions:

• Reduced upward drift in aged individuals may be linked to attenuated glycogenolysis, lactate production, or loss of type II muscle fibers.
• Slower recovery in the elderly is potentially due to age-related decreases in CO2 chemosensitivity, impairing CO2 load elimination.
• These findings highlight distinct cardiorespiratory adaptations to exercise and recovery in aging populations.