Journal of Applied Physiology, Vol 55, Issue 3 891-896, Copyright © 1983 by American Physiological Society
Effects of prior dynamic leg exercise on static effort of the elbow flexors
J. W. Yates, L. B. Gladden and M. K. Cresanta
The isometric endurance of the elbow flexors was determined in a control
condition and subsequent to a maximal effort exercise bout on a cycle
ergometer in seven subjects. Maximum voluntary contraction (MVC), peak rate
of tension development (+dP/dt), peak rate of tension relaxation (-dP/dt),
one-half contraction time, and one-half relaxation time were also measured.
Each subject was tested on four occasions: two control and two experimental
sessions. During the control sessions each subject held 40% of MVC to
exhaustion, whereas the experimental session included a 1-min maximal
effort exercise bout on a cycle ergometer 6 min prior to the isometric
endurance task. Arterialized blood samples were drawn and analyzed for
lactate, pH, PCO2, and PO2. Plasma bicarbonate was calculated from the
Henderson-Hasselbalch equation. Subsequent to the cycle ergometer bout,
blood lactate concentration rose from 0.8 to 11 mM, pH decreased from 7.43
to 7.20, PCO2 decreased from 40 to 32 Torr, and plasma bicarbonate
decreased from 26 to 12 mM. When compared with the control values, no
significant changes were evident for any muscle contractile properties
following the cycle ergometer bout. However, isometric endurance was
significantly reduced from 115.0 +/- 7.2 to 86.3 +/- 7.3 s.(ABSTRACT
TRUNCATED AT 250 WORDS)
