Post-exercise Hyperemia after Ischemic and Non-ischemic Isometric Handgrip Exercise

Abstract

Post-exercise related time course of muscle oxygenation during recovery provides valuable information on peripheral vascular disease. The purpose of the present study was to examine post-exercise hyperemia (forearm blood flow; FBF, Doppler ultrasound) assessed by peak FBF, excess FBF and the time constant for FBF (FBF Tc ) following isometric handgrip exercise (IHE). Post-exercise hyperemia was assessed in an ischemic and non-ischemic state at different exercise intensities and durations. Peak FBF and excess FBF were defined as the maximum FBF during recovery, and the total amount of FBF volume, respectively. FBF Tc represents the time to reach approximately 37% of the change in FBF between peak FBF and resting FBF (delta peak FBF). Ten subjects performed IHE at "10% and 30% maximum voluntary contraction (MVC)" for 2 min with or without arterial occlusion (AO), followed by 2 min of AO alone (Study I). In Study II, six subjects performed 30%MVC-IHE with AO for "100%, 66%, 33% and 10% of the exhausted exercise duration" (time to exhaustion). In Study I, although peak FBF and excess FBF were significantly higher in ischemic than non-ischemic IHE for both 10% and 30%MVC (pϽ0.05), FBF Tc was similar in the ischemic and non-ischemic conditions. The peak FBF, excess FBF and FBF Tc were all significantly higher at 30% than at 10%MVC (pϽ0.05). In Study II, the peak FBF and excess FBF increased linearly compared to the absolute and relative exercise durations for ischemic IHE. FBF Tc increased exponentially when compared to the absolute and relative exercise durations. These data suggest the ischemic exercise has a larger hyperemic response compared to the non-ischemic exercise. In conclusion, the peak FBF, excess FBF and FBF Tc seen during post-exercise hyperemia are closely correlated with exercise intensity and duration, not only in non-ischemic, but also in the ischemic exercise. In combination with the ischemic exercise, these parameters could potentially prove to be valuable indicators of peripheral vascular disease.

Stretching Exercises Enhance Vascular Endothelial Function and Improve Peripheral Circulation in Patients With Acute Myocardial Infarction

“…24,25) A single bout of aerobic exercise is well known to enhance vascular endothelial function, resulting in improvement of peripheral blood flow. [26][27][28] These reports support our hypothesis that the stretching exercises improved NO-dependent vasodilation in arterioles and capillaries, resulting in increased peripheral blood flow through these vessels.…”

Effect of Duration of Muscle Relaxation during Intermittent Isometric Exercises on Deoxygenation and Lactate Accumulation in Active Muscles

“…Exercise hyperaemia is caused by the accumulation of vasodilator metabolites (e.g. lactate, potassium, and inorganic phosphate) produced in active muscles, as well as by a reduction in PO2 and pH 9,10) . Production of vasodilator metabolites is markedly increased at a muscle contraction strength of 25% MVC or higher 9) .…”

“…During the muscle relaxation phase of IIE, relief of the mechanical compression of the muscle vasculature resulting from the increase in intramuscular pressure and exercise hyperaemia 9,10) would cause a temporary increase in muscle blood fl ow, to a level exceeding that at rest before exercise. The increased muscle blood fl ow supplies the muscles with large amounts of oxygen and removes the accumulated lactate from the muscles.…”

Determination of Limb Hemodynamics During Rhythmical Muscle Contractions Assessed by Doppler Ultrasound

“…V mean was defined by averaging the mean blood velocity trace (Osada & Rådegran, 2002;Rådegran, 1997). V max was defined as the maximum outer envelope (Leyk et al, 1992;Osada et al, 1999;Osada et al, 2003). The V max obtained in the present study was expressed as the blood velocity measured at the center of the vessel.…”

“…Doppler ultrasound has furthermore been used to examine the hyperaemic response at the onset of exercise (Hughson et al, 1993;Rådegran & Saltin, 1998), steady-state (Osada & Rådegran, 2002) and recovery after exercise (Osada et al, 2003). At the onset of exercise as well as recovery after exercise, variations in blood flow may be influenced by changes in blood pressure, heart rate or strength of muscle contractions.…”