Central and peripheral hemodynamics in exercising humans: leg vs arm exercise

Abstract

In humans, arm exercise is known to elicit larger increases in arterial blood pressure (BP) than leg exercise. However, the precise regulation of regional vascular conductances (VC) for the distribution of cardiac output with exercise intensity remains unknown. Hemodynamic responses were assessed during incremental upright arm cranking (AC) and leg pedalling (LP) to exhaustion (W max ) in nine males. Systemic VC, peak cardiac output (Q peak ) (indocyanine green) and stroke volume (SV) were 18%, 23%, and 20% lower during AC than LP. The mean BP, the rate-pressure product and the associated myocardial oxygen demand were 22%, 12%, and 14% higher, respectively, during maximal AC than LP. Trunk VC was reduced to similar values at W max . At W max , muscle mass-normalized VC and fractional O 2 extraction were lower in the arm than the leg muscles. However, this was compensated for during AC by raising perfusion pressure to increase O 2 delivery, allowing a similar peak VO 2 per kg of muscle mass in both extremities. In summary, despite a lower Q peak during arm cranking the cardiovascular strain is much higher than during leg pedalling. The adjustments of regional conductances during incremental exercise to exhaustion depend mostly on the relative intensity of exercise and are limb-specific.

Arm and Intensity-Matched Leg Exercise Induce Similar Inflammatory Responses

“…Similar patterns of leukocyte mobilization have been found when modulating core temperature or exercise intensity, with the modes inducing the most pronounced adrenaline response resulting in the largest increase in monocyte numbers (27) or cytokine secretion (23,25). The nonselective upregulation of leukocyte numbers in the recovery period is likely due to the exercise-induced increase in cardiac output which is related to leukocyte demargination (8)-even though not measured in the present study, arm exercise is associated with lower maximum cardiac output than leg exercise at both submaximal and maximal intensities (5), which may explain the differences found in absolute circulating monocyte numbers.…”

Sitting position affects performance in cross-country sit-skiing

“…The current study showed higher HR in KL in SUB but no difference in MAX. In maximal time-trial arm cycling elicits, lower peak heart rate and V O 2 (Zinner et al 2016) and lower peak stroke volume which implies lower cardiac output (Calbet et al 2015) compared to leg cycling. In addition, mean blood pressure has also been observed to be higher in arm cycling compared to leg cycling (Calbet et al 2015).…”

“…In maximal time-trial arm cycling elicits, lower peak heart rate and V O 2 (Zinner et al 2016) and lower peak stroke volume which implies lower cardiac output (Calbet et al 2015) compared to leg cycling. In addition, mean blood pressure has also been observed to be higher in arm cycling compared to leg cycling (Calbet et al 2015). An increased sympathetic response in arm cycling gives a higher vasoconstrictor tone in non-active muscles and hence larger resistance in the vessels (Sawka 1986).…”

“…An increased sympathetic response in arm cycling gives a higher vasoconstrictor tone in non-active muscles and hence larger resistance in the vessels (Sawka 1986). Both active muscle mass normalized vascular conductance and fractional oxygen extraction are lower during arm exercise than leg or whole body exercise (Calbet et al 2015). This is compensated for in arm cycling by a higher perfusion pressure to increase oxygen delivery to the arms.…”

The effects of slow loaded breathing training on exercise blood pressure in isolated systolic hypertension

“…Although most exercise studies commonly involve cycle or treadmill exercise, we have chosen arm cranking, partly because upper limb work is known to be particularly challenging for the cardiovascular system (Calbet et al, ) and partly because upper limb work is a significant part of the daily lives of many of the patients who live and work in the rural community.…”