Analysis of body-composition techniques and models for detecting change in soft tissue with strength training.
The purpose of this study was to compare the ability of various body-composition assessment techniques to detect changes in soft tissue in older, weight-stable women (50-70 y of age) completing a 1-y randomized, controlled trial of progressive resistance training. The intervention group (n = 20) performed high-intensity strength-training 2 d/wk with five different exercises; the control group (n = 19) was untreated. Hydrostatic weighing, 24-h urinary creatinine, computed tomography of thigh sections, total body potassium, and tritium dilution techniques were used to measure increases in total fat-free mass (FFM) and the muscle and water components of FFM. A decrease in fat mass (by hydrostatic weighing) was seen in the strength-trained women compared with the control subjects (P - 0.01-0.0001). Anthropometry, bioelectric impedance, dual-energy X-ray absorptiometry, and total body nitrogen and carbon did not measure any significant change in soft tissue. The choice of a body-composition technique is important when designing a study expected to affect soft tissue, because not all techniques available are precise enough to detect small changes.
Nelson
M E
ME
Jean Mayer US Department of Agriculture Human Nutrition Research Center on Aging at Tufts University, Boston, MA 02111, USA.
Fiatarone
M A
MA
Layne
J E
JE
Trice
I
I
Economos
C D
CD
Fielding
R A
RA
Ma
R
R
Pierson
R N
RN
Evans
W J
WJ
D015502:Absorptiometry, Photon; D000368:Aged; D000886:Anthropometry; D001823:Body Composition / Q000502:physiology*; D015992:Body Mass Index; D001835:Body Weight; D003404:Creatinine / Q000652:urine; D017097:Electric Impedance; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D008875:Middle Aged; D009501:Neutron Activation Analysis; D010806:Physical Education and Training; D011865:Radioisotope Dilution Technique; D013848:Thigh / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed; D014316:Tritium
D014316:Tritium; D003404:Creatinine