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Reduced blood flow to contracting skeletal muscle in ageing humans: is it all an effect of sand through the hourglass?
Author(s) -
Nyberg Michael,
Hellsten Ylva
Publication year - 2015
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jp270594
Subject(s) - blood flow , ageing , skeletal muscle , medicine , nitric oxide , blood pressure , cardiology
The ability to sustain a given absolute submaximal workload declines with advancing age, likely to be due to a lower level of blood flow and O 2 delivery to the exercising muscles. Given that physical inactivity mimics many of the physiological changes associated with ageing, separating the physiological consequences of ageing and physical inactivity can be challenging; yet, observations from cross‐sectional and longitudinal studies on the effects of physical activity have provided some insight. Physical activity has the potential to offset the age‐related decline in blood flow to contracting skeletal muscle during exercise where systemic blood flow is not limited by cardiac output, thereby improving O 2 delivery and allowing for an enhanced energy production from oxidative metabolism. The mechanisms underlying the increase in blood flow with regular physical activity include improved endothelial function and the ability for functional sympatholysis – an attenuation of the vasoconstrictor effect of sympathetic nervous activity. These vascular adaptations with physical activity are likely to be an effect of improved nitric oxide and ATP signalling. Collectively, precise matching of blood flow and O 2 delivery to meet the O 2 demand of the active skeletal muscle of aged individuals during conditions where systemic blood flow is not limited by cardiac output seems to a large extent to be related to the level of physical activity.