|
|
|
|
JOURNAL
OF
SPORTS SCIENCE &
MEDICINE
|
 |
|
Research
article
|
EFFECT OF HEAT PRECONDITIONING BY MICROWAVE HYPERTHERMIA ON HUMAN SKELETAL MUSCLE AFTER ECCENTRIC EXERCISE |
|||||||||
Norio Saga, Shizuo Katamoto and Hisashi Naito  |
|||||||||
Department of Exercise Physiology, Graduate School of Health and Sports Science, Juntendo University, Chiba, Japan. |
|||||||||
|
|||||||||
© Journal of Sports Science and Medicine (2008) 7, 176 - 183 Search Google Scholar for Citing Articles |
|||||||||
|
|
| ABSTRACT | |||
| The purpose of this study was to clarify whether heat preconditioning
results in less eccentric exercise-induced muscle damage and muscle soreness,
and whether the repeated bout effect is enhanced by heat preconditioning
prior to eccentric exercise. Nine untrained male volunteers aged 23 ± 3
years participated in this study. Heat preconditioning included treatment
with a microwave hyperthermia unit (150 W, 20 min) that was randomly applied
to one of the subject's arms (MW); the other arm was used as a control (CON).
One day after heat preconditioning, the subjects performed 24 maximal isokinetic
eccentric contractions of the elbow flexors at 30°·s-1 (ECC1). One week
after ECC1, the subjects repeated the procedure (ECC2). After each bout
of exercise, maximal voluntary contraction (MVC), range of motion (ROM)
of the elbow joint, upper arm circumference, blood creatine kinase (CK)
activity and muscle soreness were measured. The subjects experienced both
conditions at an interval of 3 weeks. MVC and ROM in the MW were significantly
higher than those in the CON (p < 0.05) for ECC1; however, the heat preconditioning
had no significant effect on upper arm circumference, blood CK activity,
or muscle soreness following ECC1 and ECC2. Heat preconditioning may protect
human skeletal muscle from eccentric exercise-induced muscle damage after
a single bout of eccentric exercise but does not appear to promote the repeated
bout effect after a second bout of eccentric exercise.
Key words: delayed-onset muscle soreness, muscle damage, repeated bout effect, heat shock proteins. |
|