Andy
Senior Member (Voting rights)
Introduction
Cardiovascular adjustments during exercise are an essential part of an integrated physiological response which supports muscular work. Fatigue resistance and exercise tolerance are influenced by the matching of blood flow (perfusion) to increased metabolic demands of contracting muscles. In healthy individuals, acute reduction in muscle perfusion impairs muscle endurance (1-3), fatigability (1, 4, 5) and exercise tolerance (6-8). These performance characteristics are severely impaired in patients with peripheral arterial disease who have blunted muscle hyperaemic responses (9-11). There are excellent reviews about skeletal muscle fatigue focused on intracellular (12), neural (13, 14) and cardiovascular mechanisms (15, 16), but they do not focus on effects of perfusion per se.
Contractility is the force output for a given level of muscle activation (17, 18). Unlike fatigue, a decline in force output during repeated contractions (14, 19), contractility can increase or decrease and is bi-directional. Four studies published between 1962-2013 investigated the effect of perfusion on contractility and provide consistent evidence of its reversibility. As explored in this perspective31article, this evidence suggests that muscle contractility is powerfully modulated by perfusion with implications for understanding cardiovascular adjustments during exercise, postural effects on performance, as well as exercise-related cardiovascular pathology.
Open access
Cardiovascular adjustments during exercise are an essential part of an integrated physiological response which supports muscular work. Fatigue resistance and exercise tolerance are influenced by the matching of blood flow (perfusion) to increased metabolic demands of contracting muscles. In healthy individuals, acute reduction in muscle perfusion impairs muscle endurance (1-3), fatigability (1, 4, 5) and exercise tolerance (6-8). These performance characteristics are severely impaired in patients with peripheral arterial disease who have blunted muscle hyperaemic responses (9-11). There are excellent reviews about skeletal muscle fatigue focused on intracellular (12), neural (13, 14) and cardiovascular mechanisms (15, 16), but they do not focus on effects of perfusion per se.
Contractility is the force output for a given level of muscle activation (17, 18). Unlike fatigue, a decline in force output during repeated contractions (14, 19), contractility can increase or decrease and is bi-directional. Four studies published between 1962-2013 investigated the effect of perfusion on contractility and provide consistent evidence of its reversibility. As explored in this perspective31article, this evidence suggests that muscle contractility is powerfully modulated by perfusion with implications for understanding cardiovascular adjustments during exercise, postural effects on performance, as well as exercise-related cardiovascular pathology.
Open access