Effect of exercise training intensity on abdominal visceral fat and body composition

Abstract

The metabolic syndrome is a complex clustering of metabolic defects associated with physical inactivity, abdominal adiposity, and aging.

Purpose: To examine the effects of exercise training intensity on abdominal visceral fat (AVF) and body composition in obese women with the metabolic syndrome.

Methods: Twenty-seven middle-aged obese women (mean +/- SD; age = 51 +/- 9 yr and body mass index = 34 +/- 6 kg x m(-2)) with the metabolic syndrome completed one of three 16-wk aerobic exercise interventions: (i) no-exercise training (Control): seven participants maintained their existing levels of physical activity; (ii) low-intensity exercise training (LIET): 11 participants exercised 5 d x wk(-1) at an intensity < or = lactate threshold (LT); and (iii) high-intensity exercise training (HIET): nine participants exercised 3 d x wk(-1) at an intensity > LT and 2 d x wk(-1) < or = LT. Exercise time was adjusted to maintain caloric expenditure (400 kcal per session). Single-slice computed tomography scans obtained at the L4-L5 disc space and midthigh were used to determine abdominal fat and thigh muscle cross-sectional areas. Percent body fat was assessed by air displacement plethysmography.

Results: HIET significantly reduced total abdominal fat (P < 0.001), abdominal subcutaneous fat (P = 0.034), and AVF (P = 0.010). There were no significant changes observed in any of these parameters within the Control or the LIET conditions.

Conclusions: The present data indicate that body composition changes are affected by the intensity of exercise training with HIET more effectively for reducing total abdominal fat, subcutaneous abdominal fat, and AVF in obese women with the metabolic syndrome.

Figures

Figure 1

Distribution of study participants.

Figure 2

Effects 16 weeks of no exercise training (Control, n = 7), low-intensity exercise training (LIET, n = 11), and high-intensity exercise training (HIET, n = 9) on abdominal subcutaneous abdominal fat (B), visceral fat (A), total mid-thigh skeletal muscle (C) and total mid-thigh fat (D) cross-sectional area. The values shown represent the individual percent change (%Δ values (open-circles), the mean %Δvalues (solid square), the median %Δ values (box-split), the lower (bottom of the box) and upper quartiles (top of the box), and the minimum and maximum %Δvalues (lines) by condition. Two-way, mixed-effects analysis of variance of covariance with repeated measures (ANCOVA) was employed to examine mean differences in pre- to posttraining values, with the baseline values serving as the covariate (see methods for details). For all analyses, linear contrasts of the means were constructed to test our a priori hypotheses. Fisher’s Restricted Least Significant Differences criterion was utilized to maintain the a priori type I error rate of 0.05.