HIIT Versus MICT on Abdominal Fat Mass and Lipid Oxidation in Postmenopausal Women (MATISSE)

Study Overview
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Brief Summary
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Postmenopausal women, as men, are more prone to central or android obesity than premenopausal women. Abdominal fat mass accumulation is associated with an increase of cardiovascular disease (CVD) risk. Most exercise programs designed for weight loss have focused on about 30 min several times per week of moderate intensity continuous training (MICT). Disappointingly, such exercise programs have led to either none or low fat loss. Accumulating evidence suggests that high intensity interval training (HIIT) should be an effective exercise protocol for reducing body fat of overweight individuals, especially at the abdominal level. Resistance Training (RT) is associated with increased muscle mass and strength gain in main muscles groups. Thus, RT seems to be an interesting strategy to fight against deconditioning and autonomy loss with age. Development of muscle mass enhances resting metabolism rate. Thus, RT could raise daily energy expenditure ie. substrates' oxidation including lipids. The aim of our study was to compare the effects of a 12-week moderate intensity continuous training (MICT) program with high intensity interval training (HIIT) program combined or not with a resistance training (RT) program on total abdominal and visceral fat mass and substrate utilization in postmenopausal women. It is hypothesized that HIIT compared to MICT program would result in significantly greater whole body and regional fat mass losses (abdominal and visceral) and would improve lipid oxidation at rest and during prolonged moderate exercise. It is also hypothesized that HIIT associated with RT could be the best strategy to reduce fat mass.

Detailed Description
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Overweight and obesity are dramatically spreading worldwide, and these trends are occurring in both developed and developing countries. Fat mass and more particularly abdominal fat mass is related to the development of cardio-vascular diseases (CVD). Postmenopausal women, as men, are more prone to central or android obesity. Most exercise programs designed for weight loss have focused on about 30 min several times a week of moderate intensity continuous training (MICT). Disappointingly, such exercise programs have led to either none or low fat losses. Accumulating evidence suggests that high intensity interval training (HIIT) could be an effective exercise protocol for reducing adipose tissue of overweight individuals, especially at the abdominal level. HIIT involves brief high-intensity, anaerobic exercise followed by brief but slightly longer bouts of very low-intensity exercise. Resistance training (RT) program are currently proposed in order to reduce fat mass / preserve fat-free mass. Their beneficial effects have been demonstrated, especially in the elderly. Through development (or maintenance) of muscle mass, RT increases resting metabolism rate, daily energy expenditure, and substrate (fatty acids) oxidation. The aim of the study was to compare the effects of a 12-week moderate intensity continuous training (MICT) program with high intensity interval training (HIIT) combined or not with resistance training (RT) program on total, abdominal and visceral fat mass and substrate utilization at rest and during exercise in postmenopausal women. 36 postmenopausal women will be randomly assigned to MICT (n= 12) or HIIT (n= 12) or HIIT + RT (n= 12) group. Subjects performed three sessions per week during 12 weeks, on bicycle. MICT: For the MICT protocol, each subject performed 35 min at 50% maximal aerobic power (MAP). HIIT: For the HIIT protocol, each subject performed repeated cycles of sprinting for 8 s and pedaling slowly for 12 s (between 20 and 30 rpm) for a maximum of 60 repeats per session. HIIT+RT: For the HIIT+RT protocol, each subject performed HIIT protocol. Then they performed a single set of 8 exercises with 1 or 2min resting period between exercises. Each set consisted of 8-12 repetitions at about 80% maximum repetition (MR). Total body and regional fat content will be measured using dual-energy x-ray absorptiometry (DEXA) before and after the intervention (3 months). The investigators will examine the effects of HIIT, MICT and HIIT + RT programs on: Total fat mass (and appendicular fat mass) (DEXA) Total fat free mass (and appendicular fat free mass) (DEXA) Glycemic profile (plasma HbA1c, plasma glucose) Lipid profile (TG, HDL, LDL, total cholesterol) Substrates oxidation at rest and during moderate exercise (40min, 50% of maximal oxygen consumption VO2 max) Statistical analysis Appropriate sample size has been calculated given previous results about fat mass loss during HIIT in women and considering the dropouts observed in this type of protocol. Gaussian distribution of the data will be tested by the Kolmogorov-Smirnov test. Data will be presented as mean ± standard deviation (SD). Comparisons between groups will be made with Mann & Whitney U test or ANOVA when appropriate. Relationships between data will be assessed by Pearson correlation. Significance will be accepted at the p<0.05 level. Statistical procedures will be performed using Statistica software.

Official Title
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Effect of High-Intensity Interval Training and Moderate-Intensity Continuous Training on Abdominal Fat Mass and Energy Substrates Utilization in Postmenopausal Women

Conditions
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Overweight, Post Menopausal Women

Intervention / Treatment
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* Other: Training programs


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Postmenopausal women (55- 82 years) BMI ≥ 25 and < 40 Able to follow an exercise protocol Eating behavior and physical activity stable since at least 3 month Exclusion Criteria: Subject not able to perform exercise after medical examination Subject not able to perform bicycle exercise (pains) Chronic infection Use of β-blocker Medical treatment that could interfere with the different outcome measures Hormonal Replacement Therapy (HRT) Regular consumption of alcohol Refusal to sign the consent form

Ages Eligible for Study
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Minimum Age: 55 Years
Maximum Age: 82 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: High Intensity Interval Training program (HIIT)<br>Subjects perform three sessions of training during 12 weeks: 35 min at 50% maximal aerobic power on bicycle. | Other: Training programs<br>* High Intensity Interval Training program (HIIT) vs. Moderate Intensity Continuous Training program (MICT) vs. High Intensity Interval Training program + Resistance Training program (HIIT+RT)<br>|
| Experimental: Moderate Intensity Continuous Training program (MICT)<br>Subjects perform three sessions of training during 12 weeks: repeated cycles of sprinting for 8s and pedaling slowly for 12s (between 20 and 30 rpm) for a maximum of 60 repeats per session. | Other: Training programs<br>* High Intensity Interval Training program (HIIT) vs. Moderate Intensity Continuous Training program (MICT) vs. High Intensity Interval Training program + Resistance Training program (HIIT+RT)<br>|
| Experimental: HIIT + Resistance Training program (RT)<br>Subjects perform three sessions of training during 12 weeks: Each subject performed HIIT protocol and then a single set of 8 exercises with 1 ou 2min resting period between exercises. Each set consisted of 8-12 repetitions at about 80% maximum repetition. | Other: Training programs<br>* High Intensity Interval Training program (HIIT) vs. Moderate Intensity Continuous Training program (MICT) vs. High Intensity Interval Training program + Resistance Training program (HIIT+RT)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from baseline abdominal fat mass (g) after 3 months of training (T3-T0/T0 x 100) | Total abdominal fat mass will be measured in all patients using DEXA based on the methodology of Martin and Jensen (1991; L1-L2 to pubic rami) before (baseline, T0) and after 3 months of training (T3). | Baseline T0, 3 months after protocol starting | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Lipids oxidation evaluated by gas exchange measurements | Evolution of lipids oxidation at rest and during prolonged moderate intensity (40min, 50% of VO2max) using an automated gas analysis system. Carbon dioxide (CO2) production and oxygen consumption (CO2) are expressed in L/min. Respiratory exchange ratio is the ratio between CO2 production and O2 consumption (RER = VCO2/VO2). | 1 week, 3 months after protocol starting | 
| Visceral fat mass | Change from baseline in visceral fat mass (g) (estimated from DEXA) | Baseline T0, 3 months after protocol starting | 
| Total fat mass | Change from baseline in total fat mass (g) (determined from DEXA) | Baseline T0, 3 months after protocol starting | 
| Fat-free mass | Change from baseline in total fat-free mass (g) (determined from DEXA) | Baseline T0, 3 months after protocol starting | 
| Plasma HbA1c | Change from baseline in plasma HbA1c | Baseline T0, 3 months after protocol starting | 
| Glucose level | Change from baseline in plasma glucose measurement | Baseline T0, 3 months after protocol starting | 
| Plasma triglycerides | Change from baseline in plasma triglycerides | Baseline T0, 3 months after protocol starting | 
| Plasma total cholesterol | Change from baseline in total cholesterol | Baseline T0, 3 months after protocol starting | 
| Plasma HDL-cholesterol | Change from baseline in HDL-cholesterol | Baseline T0, 3 months after protocol starting | 
| Plasma LDL-cholesterol | Change from baseline in LDL-cholesterol | Baseline T0, 3 months after protocol starting | 
| Insulin level | Change from baseline in plasma insulin measurement | Baseline T0, 3 months after protocol starting | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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interval training, abdominal fat mass, postmenopausal women, lipids oxidation