What could be causing my decline in physical performance as a former competitive runner?

Causes of Physical Performance Decline in Former Competitive Runners

The most likely cause of your decline in physical performance as a former competitive runner is age-related physiological changes, particularly decreased aerobic capacity which declines at approximately 10% per decade after age 25, compounded by potential low energy availability if training has continued without adequate nutritional support.1

Age-Related Physiological Changes

• Aerobic cardiovascular function naturally declines with age, with maximal oxygen consumption (VO2max) decreasing at an average rate of 10% per decade after age 25, regardless of continued training status 1
• This decline accelerates from about age 70 onwards, though regular physical activity can attenuate this decline compared to sedentary individuals 2
• Muscular changes underlying performance declines include progressive loss of muscle mass, decreased force and power-generating capacity, reduced flexibility, and decline in specific tension 2
• Cardiovascular system changes include decreased stroke volume, reduced cardiac output, and increased cardiac and vascular stiffness 2

Relative Energy Deficiency in Sport (RED-S)

• If you've maintained training without adequate nutritional support, low energy availability (EA) can significantly impact performance 1
• The RED-S model identifies 10 negative performance effects of low EA: increased injury risk, decreased training response, impaired judgment, decreased coordination, decreased concentration, increased irritability, depression, decreased glycogen stores, decreased muscle strength, and decreased endurance performance 1
• Studies have shown that athletes with low EA experience significant performance decrements - one study of swimmers showed a 9.8% decline in performance times in those with ovarian suppression (a marker of low EA) versus an 8.2% improvement in those with normal hormonal function 1
• Resting metabolic rate decreases in energy deficiency, further compromising performance capacity 1

Functional Decline Markers

• Decreased mobility performance is a significant marker of functional decline in aging adults 3
• Gait speed, stride length, and other physical performance metrics show measurable declines that correlate with overall functional status 4
• Low physical performance is associated with increased disability risk, falls, and hospitalization in longitudinal studies 4

Biomechanical Adaptations

• Long-term runners often experience biomechanical changes that can affect performance efficiency 1
• Changes in stride length, trunk gradient, and joint angles during running can reduce running economy 1
• These biomechanical alterations may be more pronounced after years of competitive running and can contribute to decreased performance 1

Cardiovascular Considerations

• Masters athletes (typically over 35 years old) may develop cardiovascular changes that affect performance 1
• Recent studies show that long-term endurance exercise can be associated with increased incidence of atrial fibrillation, atherosclerotic plaques, and aortic dilation, particularly in men 2
• Chronotropic incompetence (inadequate heart rate response to exercise) can develop with age and significantly impact performance 1

Assessment and Management Approach

• Evaluate energy availability by assessing nutritional intake relative to exercise energy expenditure 1
• Ensure adequate caloric intake with proper macronutrient distribution, particularly focusing on sufficient carbohydrates to maintain glycogen stores 1
• Consider iron status, as iron deficiency (with or without anemia) is common in endurance athletes and can significantly impact performance 1
• Assess physical impairments that contribute to functional decline, including muscle force production, flexibility, and cardiovascular fitness 5
• Implement targeted interventions for identified physical impairments to improve activities of daily living and athletic performance 5

Key Considerations for Former Competitive Runners

• Performance expectations should be adjusted based on age-related physiological changes 1
• Nutritional needs must be reassessed as metabolism changes with age and activity levels 1
• Recovery requirements typically increase with age, necessitating more rest between intense training sessions 2
• Monitoring for signs of overtraining or energy deficiency is crucial for maintaining performance and health 1