Clinical trial NCT03236285: Microvascular and Metabolic Effects of High-intensity Interval Exercise Training
Official title: Microvascular and Metabolic Effects of High-intensity Interval Training (HIIT) and Intermittent Fasting (FAST) in Overweight or Obese, Sedentary Women With Cardiometabolic Risk Factors: HIIT-FAST, a Randomized Clinical Trial
Study type: INTERVENTIONAL
Overall status: WITHDRAWN
Phase: NA
Conditions: Obesity
Overweight
Physical Activity
Keywords: Obesity
Microcirculation
Endothelial function
Laser speckle imaging
Capillary density
Lead sponsor: National Institute of Cardiology, Laranjeiras, Brazil
Sponsor class: OTHER_GOV
First posted: 2017-08-01
Enrollment: 0
Sex: FEMALE
Minimum age (years): 30
Maximum age (years): 50
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: SUPPORTIVE_CARE

Brief summary: The study investigates the effects of high intensity interval training (HIIT) versus continuous training (CT), combined or not with fasting, on capillary density, microvascular function, cardiometabolic risk markers, functional capacity, and quality of life, in overweight or obese sedentary women with cardiometabolic risk factors. The use of HIIT could promote greater improvements in these parameters than CT. Furthermore, the positive effects of exercise may increase when it is performed in the fasting state, compared to exercise performed in the fed state.

Detailed description: Physical inactivity and increased caloric intake play important roles in the pathophysiology of obesity. Increases of physical activity and modifications of eating behaviors are first-line interventions which, however, are not easily implemented, and lack of time to exercise and difficulties in coping with different diets are common reasons for failure. High-intensity interval training (HIIT) is a "faster" alternative to moderate-intensity continuous training (CT). Conversely, intermittent fasting is also an alternative to more complex diets, as it restricts caloric intake to a specified period of time without major diet composition changes. The combination of HIIT and fasting may therefore provide incremental benefits.

Sedentary women aged ≥ 30 years and ≤50 years, with body mass index ≥25 kg/m2 and cardiometabolic risk factors, will be randomized to HIIT performed in the fasting state, HIIT performed in the fed state, CT in the fasting state or CT in the fed state. Cardiometabolic parameters, anthropometric indices, cardiorespiratory fitness, quality of life and microvascular function (cutaneous capillary density and microvascular reactivity evaluated by laser speckle contrast imaging) will be evaluated before the initiation of the interventions and 4 weeks thereafter.

Eligibility criteria: Inclusion Criteria:

* Female gender
* Age≥ 30 years and ≤50 years
* Premenopausal status
* Body mass index \>25 kg/m2
* At least one of the following:

waist circumference ≥80 cm (women); triglycerides ≥150 mg/dl or treatment for this lipid abnormality; High density-lipoprotein cholesterol \<50 mg/dl (women), or treatment for this abnormality; fasting plasma glucose ≥100 mg/dl

Exclusion Criteria:

* Any cardiovascular disease, including systemic hypertension
* Diabetes mellitus
* Chronic pulmonary disease
* Any systemic disease or condition that might reduce the adherence or tolerance to exercise or fasting
* Orthopedic or neurologic conditions that might impair exercise training
* Pregnancy or breastfeeding
* Abnormalities elicited at exercise treadmill testing that preclude the initiation of exercise training
* Current engagement in any exercise training protocol

Primary outcomes:
measure: Capillary density
timeFrame: 6 months
Secondary outcomes:
measure: Microvascular reactivity assessed by laser speckle contrast imaging
timeFrame: 6 months
Other outcomes:
Locations:
city: Rio de Janeiro
country: Brazil
facility: National Institute of Cardiology, Ministry of Health, Brazil
Study officials:
affiliation: National Innstitute of Cardiology
name: EDUARDO V TIBIRICA, MD, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: De Lorenzo A, Van Bavel D, de Moraes R, Tibirica EV. High-intensity interval training or continuous training, combined or not with fasting, in obese or overweight women with cardiometabolic risk factors: study protocol for a randomised clinical trial. BMJ Open. 2018 Apr 28;8(4):e019304. doi: 10.1136/bmjopen-2017-019304.