Hemodynamic responses of quadriplegics to maximal arm-cranking and FNS leg cycling exercise

Eight healthy male adults (25–34 yr) were studied to compare hemodynamic responses to static exercise (30% MVC in leg extension), static-dynamic exercise (one-arm cranking, 66 and 79% VO2 max-arm), and dynamic exercise (two-leg cycling, 58 and 82% VOmax-legs). Leg extension (LE) strength was measured by a spring scale. Cranking and cycling were performed on a Quinton bicycle ergometer. VO2 was measured using an automated open-circuit system. Heart rate (HR) was monitored from a CM-5 ECG lead, and arterial pressure (Pa) was measured from an indwelling brachial artery catheter. Cardiac output (Q) was measured using a CO2-rebreathing procedure. Total peripheral resistance (TPR) was calculated using the mean arterial pressure (Pa) as the systemic pressure gradient. In 30% LE, a significant (P less than 0.05) Pa increase occurred (pressor response) mediated primarily by an increase in Q. One-arm cranking and two-leg cycling at similar relative VO2 demands resulted in nearly identical increases in Pa due to different contributions of Q and TPR. Q and the arteriovenous O2 difference varied as a function of VO2 regardless of the mode of exercise (static or dynamic). On the other hand, the HR response, which accounted for increased Q in the exercises containing a static component, and Pa varied with mode of exercise. Any generalized scheme of cardiovascular control during exercise must account for the potential influence of dynamic and static components of the exercise.

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Moderate-intensity Arm-cranking Exercise may not Improve Arterial Function in Healthy Adult Men

International Journal of Sports Medicine ◽

10.1055/a-0664-8823 ◽

2018 ◽

Vol 39 (13) ◽

pp. 962-966

Author(s):

Hajime Miura ◽

Miduki Ishikawa ◽

Kenichi Deguchi

Keyword(s):

Healthy Adult ◽

Acute Effect ◽

Moderate Intensity ◽

Upper Arm ◽

Arm Cranking ◽

Cycling Exercise ◽

Arterial Function ◽

Adult Men ◽

Leg Cycling ◽

Arm Cranking Exercise

AbstractEndurance exercises, such as cycling or running, are useful for improving arterial function. However, people suffering from partial paralysis or arthritis are unable to perform these kinds of lower-limb exercises. In the present study, we explored the acute effect of upper-arm exercise on arterial stiffness in healthy men. Fourteen healthy adult men performed two experimental trials. The order of experiments was randomized between a 30-min arm-cranking exercise at 50% V̇O2max (A-trial) and a 30-min leg-cycling exercise at 50% V̇O2max (C-trial). The brachial to ankle pulse wave velocity (baPWV), brachial systolic/diastolic blood pressure and heart rate were obtained with subjects in the supine position. The baseline hemodynamic values were not markedly different between the two trials. Compared with the baseline value, the baPWV was significantly reduced at 30 and 60 min after the C-trial. In the A-trial, however, there were no significant changes in the baPWV throughout the trial. These results indicate that acute 50% V̇O2max arm-cranking exercise induced relatively little change in the baPWV, which was the opposite of the finding observed with leg-cycling exercise. Therefore, in order to improve arterial function via aerobic upper-arm exercises, the exercise mode/intensity or other approaches should be considered.

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Oxygen uptake and heart rate kinetics during heavy exercise: a comparison between arm cranking and leg cycling

European Journal of Applied Physiology ◽

10.1007/s00421-002-0690-5 ◽

2002 ◽

Vol 88 (1-2) ◽

pp. 100-106 ◽

Cited By ~ 32

Author(s):

Donald Schneider ◽

Andrew Wing ◽

Norman Morris

Keyword(s):

Heart Rate ◽

Oxygen Uptake ◽

Heavy Exercise ◽

Arm Cranking ◽

Leg Cycling ◽

Rate Kinetics ◽

Heart Rate Kinetics

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Arm muscle sympathetic nerve activity during preparation for and initiation of leg-cycling exercise in humans

Journal of Applied Physiology ◽

10.1152/jappl.1994.77.3.1403 ◽

1994 ◽

Vol 77 (3) ◽

pp. 1403-1410 ◽

Cited By ~ 33

Author(s):

R. Callister ◽

A. V. Ng ◽

D. R. Seals

Keyword(s):

Power Output ◽

Peak Power ◽

General Pattern ◽

Peak Power Output ◽

Movement Initiation ◽

Nerve Activity ◽

Cycling Exercise ◽

Target Power ◽

Leg Cycling ◽

Exercise In Humans

We tested the hypothesis that sympathetic vasoconstrictor nerve activity to nonactive skeletal muscle (MSNA) decreases immediately before and remains suppressed during initiation of conventional large muscle upright dynamic exercise in humans. In 11 healthy young subjects, adequate recordings of MSNA from the radial nerve in the arm were obtained during upright seated rest (control) and throughout 1 min of leg-cycling exercise at one or more submaximal workloads (range 33–266 W; approximately 10–80% of peak power output). MSNA was analyzed during four consecutive time intervals; control, preparation for cycling (end of control to onset of pedal movement), initiation of cycling (onset of pedal movement to attainment of target power output), and the initial 60 s of cycling at target power output. MSNA decreased (P < 0.05) abruptly and markedly in all subjects [to 19 +/- 4% (SE) of control levels] during the preparation period before the 33-W load and remained suppressed throughout the period of initiation of cycling in 8 of 11 subjects; MSNA increased during the initiation period in three subjects in whom diastolic arterial pressure fell below control levels. This general pattern was observed at all loads. MSNA remained at or below control levels throughout the 1 min of cycling exercise at 33–166 W. MSNA increased above control levels during the latter portion of the 1 min of cycling only at loads > or = 60% of peak power output.(ABSTRACT TRUNCATED AT 250 WORDS)

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