Title: The effect of sex on respiratory-locomotor blood flow during exercise.
Supervisor: Dr. William Sheel
Committee members: Dr. Robert Boushel, Dr. Jordan Guenette
Abstract:
During dynamic exercise, the body must match oxygen delivery to increased metabolic demand, with 85-90% of cardiac output redirected to active muscles at peak exertion. The increased workload on the respiratory muscles, particularly during high-intensity exercise, imposes a significant metabolic cost, requiring a portion of our finite cardiac output. Previous research has demonstrated sex-differences in cardiopulmonary physiology; however, it remains unclear if there are sex-differences in respiratory-locomotor blood flow during exercise.
Twenty participants (n = 10 females, n = 10 males) will be recruited and fitted with venous and arterial catheters, esophageal and gastric balloon catheters, and near-infrared spectroscopy sensors on the sternocleidomastoid and vastus lateralis.
Indocyanine green, a dye visible in the near-infrared spectrum, will be injected into the venous bloodstream while a small amount of arterial blood will be withdrawn and analyzed by a cardiac output computer during both rest and high-intensity exercise. Using indocyanine green concentration curves from the arterial blood, sternocleidomastoid, and vastus lateralis, absolute blood flow to the respiratory and locomotor muscles can be determined.
It is hypothesized that, during exercise, females will divert a greater proportion of blood flow from locomotor muscles to respiratory muscles compared to males.
This research addresses a critical gap in the literature by exploring sex-based differences in respiratory-locomotor blood flow. The findings will enhance our understanding of blood flow distribution patterns and could inform sex-specific rehabilitation in certain respiratory and cardiovascular diseases.