Muscle strength and pressor response

Int J Sports Med. 2009 May;30(5):320-4. doi: 10.1055/s-0028-1111109. Epub 2009 Feb 6.

Abstract

The purpose of this study was to determine if muscle strength influences the hyperemic response to dynamic exercise. Men with low (n=8) and high (n=9) maximal forearm strength performed dynamic handgrip exercise as the same absolute workload increased in a ramp function (0.5 kg x min (-1)). Forearm blood flow (FBF) was measured instantaneously by ultrasound Doppler and blood pressure was measured by auscultation. The pressor response to exercise was greater (P<0.05) for low strength men at workloads >1.5 kg allowing volumetric FBF (ml x min (-1)) and vascular conductance to increase in proportion to absolute workload similar to high strength men. When FBF was expressed relative to forearm volume (ml x min (-1).100 ml (-1)) the hyperemic response to exercise (slope of relative FBF vs. workload) was greater in low strength men (3.2+/-1.5 vs. 1.7+/-0.4 ml x min (-1).100 ml (-1) x kg (-1), P<0.05) as was relative FBF at workloads >1.5 kg. However, when relative FBF was compared across relative work intensity, no difference was found between low and high strength groups. Together, these findings suggest men with low strength require a greater pressor response to match blood flow to exercise intensity as compared to high strength men.

MeSH terms

  • Adult
  • Auscultation
  • Blood Pressure*
  • Exercise Test
  • Forearm / blood supply
  • Forearm / physiology
  • Humans
  • Hyperemia / metabolism
  • Male
  • Muscle Contraction / physiology*
  • Muscle Strength / physiology*
  • Ultrasonography, Doppler
  • Young Adult