| Summary: | 碩士 === 國立體育學院 === 運動科學研究所 === 82 === To examine the effects of skin temperature (Tsk) on bio-
electric impedance analysis（BIA）of resistance（R）and
reactance Xc ）, and BIA prediction equation. Twenty young
females, with age ( mean±SD ): 19.7 ±0.9 Yr, height: 160.1 ±
6.2 cm, weight: 56.8 ± 9.3 Kg, volunteered as subjects. All
subjects underwent skin temperature and BIA measuremeants under
three temperature conditions: 1) 24.9 ℃ (nomal,N), 2) 17.3
℃, (cold, C), and 3) 35.3 ℃ (hot, H). The measured R and
Xc values were used to compute fat-free mass (FFM) according
to the equations of Lukaski (1987) and Guo (1989). The
estimated FFM values were compared with the underwater
weighing method (UW). Data was tested by repeated
measurements of one-way ANOVA. If the result was
significant Tukey post-hoc test was used. Results of this
study shows that: 1)the mean Tsk and the four measured sites
( calf, thigh, bicept, and chest ) were significantly decreased
from N to C and increased from N to H; 2) the BIA measured R
values were significantly increased from N to C ( △ 25 Ω )
and decreased from N to H ( △ 20 Ω ). The Xc values
were significantly increased from N to C ( △ 6 Ω ) and
decreased from C to H ( △ 7 Ω ); 3) the FFM computed by two
BIA prediction equations were significantly decreased from N to
C and increased from N to H; 4) the Lukaski prediction equation
significantly underestimated FFM by 1.2 Kg; and 5) the
Guo rediction lquation significantly underestimated FFM by
3.0 Kg. We conclude that 1) varying skin temperature by
altering ambient temperture significantly changed the BIA
measurement of R and Xc; and 2) varying skin temperture
significantly affected the FFM determination. Thus, we
recommend that BIA measurement should be taken under
standardized ambient conditions, to avoid the effect of skin
temperature. We observed that both Lukaski(1987) and
Guo(1989) equations underestimated FFM of young Chinese female.
|
|---|
