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Assessment of Pulmonary Capillary Blood Volume, Membrane Diffusing Capacity, and Intrapulmonary Arteriovenous Anastomoses During Exercise
Published on: February 20, 2017
A sex-specific relationship between capillary density and anaerobic threshold
Jennifer L Robbins1, Brian D Duscha, Daniel R Bensimhon
1Duke University Medical Center, Division of Cardiology, Durham, North Carolina 27710, USA. j.robbins@duke.edu
Exercise training improves oxygen consumption (Vo(2)) and capillary density, but their relationship is complex. This study found that while capillary density correlates with improved anaerobic threshold in men, women show an inverse relationship, suggesting sex-specific effects.
Area of Science:
- Exercise Physiology
- Skeletal Muscle Biology
- Cardiovascular Health
Background:
- Exercise training enhances peak oxygen consumption (Vo(2)) and skeletal muscle capillary density.
- The direct relationship between these adaptations remains unclear, possibly due to peak Vo(2) being influenced by central hemodynamics rather than solely muscle oxidative potential.
Purpose of the Study:
- To investigate the relationship between changes in skeletal muscle capillary density and anaerobic threshold following exercise training.
- To determine if these relationships are sex-specific, considering baseline differences.
Main Methods:
- 28 sedentary, overweight, dyslipidemic adults (17 men, 11 women) underwent 6 months of high-intensity exercise.
- Changes in capillary density, peak Vo(2), and Vo(2) at anaerobic threshold were assessed.
- Relationships between these variables were analyzed, with a focus on sex-specific effects.
Main Results:
- No significant relationship was found between changes in peak Vo(2) and capillary density in either sex.
- Men showed a positive correlation between increased Vo(2) at anaerobic threshold and enhanced capillary density (r = 0.635, P < 0.01).
- Women exhibited an inverse relationship between these variables (r = -0.636, P < 0.05).
Conclusions:
- Enhanced skeletal muscle capillary density is linked to improved submaximal exercise performance (anaerobic threshold) in men post-training.
- The relationship between capillary density and submaximal exercise capacity differs between men and women, indicating sex-specific physiological adaptations to exercise.
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