Capillaries are very tiny blood vessels — so small that a single red blood cell can barely fit through them. They help to connect your arteries and veins in addition to facilitating the exchange of ...

Data sources Cochrane Central, PsycINFO, Embase, Medline and CINAHL. Eligibility criteria Peer-reviewed, randomised controlled trials, in English (1990–present), which examined the effects of exercise ...