The effects of exercise training in addition to energy restriction on functional capacities and body composition in obese adults during weight loss: a systematic review.

Clint T Miller,John Reynolds,Itamar Levinger,Nora E Straznicky,Steve F Fraser,John B Dixon,Steve E Selig,German E Gonzalez

doi:10.1371/journal.pone.0081692

Clint T Miller, John Reynolds + Show 6 more

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https://doi.org/10.1371/journal.pone.0081692

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Abstract

BackgroundObesity is associated with impairments of physical function, cardiovascular fitness, muscle strength and the capacity to perform activities of daily living. This review examines the specific effects of exercise training in relation to body composition and physical function demonstrated by changes in cardiovascular fitness, and muscle strength when obese adults undergo energy restriction.MethodsElectronic databases were searched for randomised controlled trials comparing energy restriction plus exercise training to energy restriction alone. Studies published to May 2013 were included if they used multi-component methods for analysing body composition and assessed measures of fitness in obese adults.ResultsFourteen RCTs met the inclusion criteria. Heterogeneity of study characteristics prevented meta-analysis. Energy restriction plus exercise training was more effective than energy restriction alone for improving cardiovascular fitness, muscle strength, and increasing fat mass loss and preserving lean body mass, depending on the type of exercise training.ConclusionAdding exercise training to energy restriction for obese middle-aged and older individuals results in favourable changes to fitness and body composition. Whilst weight loss should be encouraged for obese individuals, exercise training should be included in lifestyle interventions as it offers additional benefits.

Highlights

Increasing obesity and central adiposity leads to a greater risk of developing obesity-related morbidities and disabilities [1,2]
Obese individuals often experience the vicious cycle of low exercise capacity, physical disability and breathlessness leading to physical inactivity, in turn leading to further weight gain [9] and loss of physical function [10,11]
Inclusion and exclusion criteria Only randomised controlled trials (RCTs) that met the following criteria were included in this review: (i) published in English, (ii) cohorts were adults aged 18 years and older, (iii) the same energy restriction intervention was used in the energy restriction only and, combined exercise training with energy restriction arms of the study, (iv) mean body mass index (BMI) of participants $ 30 kg.m2, (v) Dual-energy X-ray absorptiometry (DXA), or magnetic resonance imaging (MRI), (vi) a minimum of two groups comprising energy restriction only and energy restriction plus exercise training

Summary

Introduction

Increasing obesity and central adiposity leads to a greater risk of developing obesity-related morbidities and disabilities [1,2]. Reduced capacity for activities of daily living may occur prior to the development of these conditions and may be related to adverse metabolic and biomechanical changes associated with obesity [7,8]. Midlife obesity alone can lead to a 5 times greater risk of developing old age frailty compared with healthy weight peers [12]. There appears to be an additive effect of obesity and low strength for the development of mobility disability and walking speed during aging. Obesity is associated with impairments of physical function, cardiovascular fitness, muscle strength and the capacity to perform activities of daily living. This review examines the specific effects of exercise training in relation to body composition and physical function demonstrated by changes in cardiovascular fitness, and muscle strength when obese adults undergo energy restriction

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