Muscle characteristics in career breath-hold divers: effect of water temperature.
BACKGROUND
In a previous study we reported that Korean female breath-hold divers (BHD) with life-long experience of diving in cold water (10-12 degrees C in winter and 25-27 degrees C in summer) had reduced muscle fiber size and increased capillary density. The hypothesis tested in the present study was whether prolonged habitual diving at a moderate water temperature (MWT, 29-30 degrees C all year round) similarly caused a reduction in muscle fiber size.


METHODS
The subjects were 14 Indonesian BHDs with long experience of diving at MWT, and a control group of 10 age-matched non-diving Indonesian men (CON), selected from the same tribe among which the BHDs lived. Muscle samples obtained from the middle portion of the vastus lateralis muscle were analyzed for muscle morphology by histochemical analysis and the levels of vascular endothelial growth factor (VEGF) protein by Western blotting.


RESULTS
Muscle fiber type composition was identical in both groups, and no difference in cross-sectional area (CSA), VEGF protein, or capillarity between the BHD and the CON was observed.


CONCLUSIONS
The present study demonstrated that prolonged habitual breath-hold diving at MWT does not cause any alteration in muscle fiber composition, fiber size, or capillarity.
Park
Jeong Bae
JB
Department of Social Sports, Jinju International University, Korea.
Kim
Hyo Jeong
HJ
Kim
Jae Cheol
JC
Lutan
Rusli
R
Kim
Chang Keun
CK
D000222:Adaptation, Physiological; D000328:Adult; D000693:Anaerobiosis / Q000502:physiology; D000886:Anthropometry; D015153:Blotting, Western; D001831:Body Temperature; D002196:Capillaries / Q000502:physiology; D003080:Cold Temperature / Q000009:adverse effects; D004242:Diving / Q000502:physiology*; D006801:Humans; D007101:Immersion; D008297:Male; D008875:Middle Aged; D018485:Muscle Fibers, Skeletal / Q000502:physiology*; D018482:Muscle, Skeletal / Q000033:anatomy & histology* / Q000098:blood supply / Q000378:metabolism; D012119:Respiration; D042461:Vascular Endothelial Growth Factor A / Q000096:biosynthesis; D014867:Water
D042461:Vascular Endothelial Growth Factor A; D014867:Water