%0 Journal Article
%T Continuous Exercise but Not High Intensity Interval Training Improves Fat Distribution in Overweight Adults
%A Shelley E. Keating
%A Elizabeth A. Machan
%A Helen T. O'Connor
%A James A. Gerofi
%A Amanda Sainsbury
%A Ian D. Caterson
%A Nathan A. Johnson
%J Journal of Obesity
%D 2014
%I Hindawi Publishing Corporation
%R 10.1155/2014/834865
%X Objective. The purpose of this study was to assess the effect of high intensity interval training (HIIT) versus continuous aerobic exercise training (CONT) or placebo (PLA) on body composition by randomized controlled design. Methods. Work capacity and body composition (dual-energy X-ray absorptiometry) were measured before and after 12 weeks of intervention in 38 previously inactive overweight adults. Results. There was a significant group ℅ time interaction for change in work capacity ( ), which increased significantly in CONT ( %) and HIIT ( %) but not PLA ( %). There was a near-significant main effect for percentage trunk fat, with trunk fat reducing in CONT by % and in PLA by %, but not in HIIT (increase of %) ( ). There was a significant reduction in android fat percentage in CONT ( %) and PLA ( %) but not HIIT (increase of %) ( ). Conclusion. These data suggest that HIIT may be advocated as a time-efficient strategy for eliciting comparable fitness benefits to traditional continuous exercise in inactive, overweight adults. However, in this population HIIT does not confer the same benefit to body fat levels as continuous exercise training. 1. Introduction Epidemiological data show that the majority of the adult population fails to meet recommended physical activity levels [1]. This contributes to the global epidemic of overweight/obesity and associated cardiovascular disease. A reason often cited for failure to participate in regular exercise is a perceived lack of time [2]. High intensity interval training (HIIT) could potentially provide health benefits in a time-efficient manner. This involves repeated bursts of vigorous exercise interspersed with low intensity recovery. There is growing evidence from healthy populations that HIIT leads to a range of cardiovascular and metabolic benefits that are similar to or greater in magnitude than those achieved with regular continuous aerobic exercise. These benefits include increased cardiorespiratory fitness [3每9] and work capacity [10], increased muscle mitochondrial biogenesis and GLUT-4 levels [11], and improved insulin sensitivity [4, 6, 7]. Relative to the effect of continuous aerobic exercise, HIIT has also been shown to induce comparable improvements in fitness and insulin sensitivity in clinical populations, including those with overweight/obesity [12每17], cardiovascular disease [18每21], metabolic syndrome [17], and type 2 diabetes [22每24]. In some of these studies [7, 21, 23] the benefits of HIIT were achieved with programs requiring similar training time, but most found a benefit with 50每60%
%U http://www.hindawi.com/journals/jobe/2014/834865/