HIIT Versus MICT on Abdominal Fat Mass and Lipid Oxidation in Postmenopausal Women (MATISSE)
Condition: Overweight; Post Menopausal Women
MeSH terms: Overweight
Study type: Interventional

Summary: 
      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: 
      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.
    

Intervention name(s): Training programs
Intervention type(s): Other
Intervention description(s): High Intensity Interval Training program (HIIT) vs. Moderate Intensity Continuous Training program (MICT) vs. High Intensity Interval Training program + Resistance Training program (HIIT+RT)
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Participant)
Primary purpose: Prevention
Keywords: interval training; abdominal fat mass; postmenopausal women; lipids oxidation