Obese
Conditions
Brief summary
This study aims to investigate the efficacy of a novel home-based high-intensity interval training (Home-HIT) intervention in obese individuals, with elevated cardiovascular disease (CVD) risk. It was hypothesised that Home-HIT would 1) have high adherence to the prescribed exercise intensity (compliance), 2) improve markers of CVD risk, and 3) lead to favourable skeletal muscle adaptations.
Detailed description
The applicability of current high intensity interval training (HIT) protocols to the sedentary obese population has been disputed by public health experts. Existing HIT interventions have been successful only under optimal conditions with high levels of supervision and specialised equipment, creating further barriers to exercise in those most in need. We aimed to eliminate many of these barriers by modifying existing HIT protocols to create a new home-based HIT (Home-HIT) intervention tailored to individuals with low fitness and mobility. It was hypothesised that Home-HIT would 1) have high adherence to the prescribed exercise intensity (compliance) and 2) improve markers of cardiovascular disease (CVD) risk. 32 Obese adults with at least 3 additional CVD risk factors (age 36±2 y; BMI 34.3±0.8 kg∙m-2; VO2peak 24.6±1.0 ml∙kg∙min-1), completed one of three 12-week training programmes 3x/week: Home-HIT (n=9); Laboratory-based supervised HIT (Lab-HIT; n=10) or home-based moderate intensity continuous training (Home-MICT; n=13). Adherence and compliance were monitored online in almost real time using a heart rate (HR) monitor and mobile app. The Home-HIT group completed 4 progressing to 8 1min intervals interspersed with 1min of rest in an unsupervised place of their choosing. The intervals were composed of simple bodyweight exercises that required no equipment. Changes in VO2peak, insulin sensitivity, body composition, flow-mediated dilation (FMD) and aortic pulse wave velocity (PWV) were assessed. Muscle biopsies were taken to assess changes in capillarisation, mitochondrial density, intramuscular triglyceride (IMTG) content and eNOS and GLUT4 protein expression using quantitative immunofluorescence microscopy.
Interventions
BEHAVIORALTraining mode
type of exercise training completed for 12 weeks
Sponsors
Liverpool John Moores University
Study design
Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 55 Years
Healthy volunteers
No
Inclusion criteria
* obesity (BMI \>30 kg/m2) * age 18-55
Exclusion criteria
* diagnosed CVD and other contraindications to participate in an exercise intervention * BMI \<30 kg/m2
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| change in aerobic fitness | change in baseline aerobic fitness at 12 weeks | change in maximal aerobic capacity following the training |
| Adherence and compliance to the exercise training intervention | adherance and compliance to the training over the 12 weeks | Session completion rate (adherence) and ability to meet target heart rates (compliance) |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| change in baseline FMD | change in baseline FMD at 12 weeks | endothelial function measured using flow-mediated dilation (FMD) |
| change in vascular stiffness | change in baseline vascular stiffness at 12 weeks | change in vascular stiffness with training |
| change in body fat percentage | chage in baseline body fat percentage at 12 weeks | change in body fat percentage using DXA with training |
Countries
United Kingdom
Outcome results
None listed