Randomized Controlled Trial of Training Intensity in Adiposity

Abstract

The purpose of the study was to examine the effects of training intensity on abdominal fatness reduction and improvements of metabolic risk factors in Korean women (N=45, aged 45.4±7.3 yrs). Subjects were randomly assigned to control (CON, N=15) or low-intensity exercise (LIEX, N=15) or high-intensity exercise (HIEX, N=15). The LIEX and HIEX groups participated in a 12-wk exercise intervention at intensities of 40-50% and 70-75% of VO (2)max, respectively. Outcome assessments performed at baseline and at the end of 12-wk period included abdominal adipose tissues, VO (2)max, blood lipids, fasting glucose and insulin, and LPL- and HSL-mRNAs in abdominal subcutaneous adipose tissue (SAT). Unlike the CON group, women in the exercise groups had significant improvements in VO (2)max (+11%, P<0.001), SAT (-12%, P=0.026), TG (-23%, P=0.002), HDLC (+7.2%, P=0.013), insulin (-23%, P=0.037), and HOMA-IR (-25%, P=0.015) relative to baseline values. Changes in baseline CRF were in a dose-dependent manner based in intensity (-1.2±1.7, 2.1±2.8, and 4.7±3.2 ml/kg/min for CON, LIEX, and HIEX, respectively, P<0.001). We found no evidence that LIEX- and HIEX differ in their effects on abdominal adiposity, risk factors, and LPL- and HSL-mRNA expressions in SAT. In conclusion, the current findings suggest that low- and high-intensity exercise are equally effective in reducing abdominal adiposity and in improving risk factors.