| The purpose of this study was to investigate the effects of creatine
monohydrate supplementation on exercise performance and contractile
variables in aerobic-anaerobic training rats. Twenty 90-day-old male
Sprague Dawley rats were divided into two groups - creatine (Cr) and
controls (K). The creatine group received creatine monohydrate as
a nutritional supplement, whereas the control group was given placebo.
Both groups were trained 5 days a week on a treadmill for 20 days
in a mixed (aerobic-anaerobic) metabolic working regimen (27 m·min-1,
15% elevation for 40 min). The exercise performance (sprint-test),
contractile properties (m. tibialis anterior), oxidative enzyme activity
(SDH, LDH, NADH2) in m. soleus and blood hematological and chemical
variables were assessed in the groups at the end of the experiment.
It was found out that creatine supplementation improved the exercise
performance after 20 days of administration in a dose of 60 mg per
day on the background of a mixed (aerobic-anaerobic) exercise training.
At the end of the trial the Cr-group demonstrated better values for
the variables which characterize the contractile properties of m.
tibialis anterior containing predominantly types IIA and IIB muscle
fibers. On the other hand, a higher oxidative capacity was found out
in m. soleus (type I muscle fibers) as a result of 20-day creatine
supplementation. No side effects of creatine monohydrate supplementation
were assessed by the hematological and blood biochemical indices measured
in this study.
KEY
WORDS: Exercise,
creatine supplementation, rats, performance, muscle contractile
properties.
|
