Abstract
Serum creatine kinase (CK) activity and subjective ratings of muscle soreness were
assessed in 28 college women following three different arm flexion exercise regimens.
The subjects were randomly assigned to an eccentric, isometric, or concentric exercise
regimen. Each regimen was equated for total work time and work-to-rest ratio. Blood
samples for determination of serum CK activity and perceived soreness ratings were
obtained prior to and 5, 10, and 25 h following each exercise. Significant increases
in perceived soreness ratings were observed for each exercise regimen. The magnitude
of the post-exercise increase in perceived soreness was greatest for the eccentric
and the isometric exercises with minimal soreness following the concentric exercise.
A small but significant increase in serum CK activity was observed following the three
exercises (eccentric = 35.8%, concentric = 37.6%, isometric = 34.0%). The post-exercise
serum CK increases did not differ significantly among the three regimens. The rise
in serum CK activity suggests that muscle damage occurred during all three tasks.
However, due to multiple factors which can affect serum CK levels, the increase in
serum CK activity may not provide a sensitive indicator of the magnitude of the injury.
Key words
serum creatine kinase - muscle soreness
