Original articles  BODY COMPOSITION, SPORT NUTRITION AND SUPPLEMENTATION 

The Journal of Sports Medicine and Physical Fitness 2002 March;42(1):38-44

Copyright © 2009 EDIZIONI MINERVA MEDICA

lingua: Inglese

The influence of transient change of total body water on relative body fats based on three bioelectrical impedance analyses methods. Comparison between before and after exercise with sweat loss, and after drinking

Demura S. ¹, Yamaji S. ², Goshi F. ³, Nagasawa Y. ⁴

1Faculty of Education, Kanazawa University, Japan; 2Fukui National College of Technology, Japan; 3Miyagi Gakuin Women’s College, Japan; 4Akita Prefectural College of Agriculture, Japan

Back­ground. The pur­pose of ­this ­study was to ­clarify the influ­ence of ­change of ­total ­body ­water ­caused by exer­cise and ­drinking, on relative body fat (%BF) ­based on ­three bioelectrical impedance analyses (BIA) ­methods, ­between ­hand and ­foot (H-F), ­between ­hand and ­hand (H-H), and ­between ­foot and ­foot (F-F).
­Methods. The sub­jects ­were 30 Jap­a­nese ­healthy ­young ­adults ­aged 18 to 23 ­years (15 ­males, 15 ­females). Meas­ure­ments ­were ­made ­three ­times for ­each BIA ­method; ­before and ­after exer­cise ­with ­sweat, and ­after ­drinking, and ­also ­twice ­according to the under water weighing (UW) ­method, ­before exer­cise and ­after ­drinking. A ped­aling exer­cise, ­with a ­bicycle ergom­eter, was ­used for 60 min­utes as the exer­cise.
­Results. The rela­tion­ship of %BF ­between the UW ­method and ­each BIA ­method was mid-­range or ­more (r=0.765-0.839). How­ever, %BF ­based on the H-F and F-F BIA ­methods ­were ­higher ­than ­that ­based on the UW ­method. ­After ­drinking, %BF of all the BIA ­methods ­were ­higher ­than the UW ­method. %BF of the BIA ­methods ­after exer­cise indi­cated ­values ­lower ­than ­those ­before exer­cise. %BF of the H-F and H-H BIA ­methods ­after ­drinking ­were a ­little ­higher ­than ­those ­before exer­cise, indi­cating ­that ­those meas­ure­ments ­reflect a ­slight ­change of ­body ­water.
Con­clu­sions. It was dem­on­strated ­that %BF of any BIA ­method ­reflect the ­change of ­body ­water ­caused by exer­cise, ­sweating, and ­drinking.