Clinical trial NCT03557736: Home-Based HIT in Obese Individuals
Official title: Effects of a 12-Week Home-Based High-Intensity Interval Training Programme in Obese Individuals With Elevated Cardiovascular Disease Risk: A Pilot Study
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Obese
Lead sponsor: Liverpool John Moores University
Sponsor class: OTHER
First posted: 2018-06-15
Enrollment: 32
Sex: ALL
Minimum age (years): 18
Maximum age (years): 55
Standard ages: ADULT
Accepts healthy volunteers: no
Allocation: NON_RANDOMIZED
Intervention model: PARALLEL
Primary purpose: BASIC_SCIENCE

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.

Eligibility criteria: 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

Primary outcomes:
measure: change in aerobic fitness
timeFrame: change in baseline aerobic fitness at 12 weeks
measure: Adherence and compliance to the exercise training intervention
timeFrame: adherance and compliance to the training over the 12 weeks
Secondary outcomes:
measure: change in baseline FMD
timeFrame: change in baseline FMD at 12 weeks
measure: change in vascular stiffness
timeFrame: change in baseline vascular stiffness at 12 weeks
measure: change in body fat percentage
timeFrame: chage in baseline body fat percentage at 12 weeks
Other outcomes:
Locations:
city: Liverpool
country: United Kingdom
facility: Liverpool John Moores University
state: Merseyside
Study officials:
References:
citation: Scott SN, Shepherd SO, Hopkins N, Dawson EA, Strauss JA, Wright DJ, Cooper RG, Kumar P, Wagenmakers AJM, Cocks M. Home-hit improves muscle capillarisation and eNOS/NAD(P)Hoxidase protein ratio in obese individuals with elevated cardiovascular disease risk. J Physiol. 2019 Aug;597(16):4203-4225. doi: 10.1113/JP278062. Epub 2019 Jul 15.