Hybrid Exercise Training for Weight Loss

Study Overview
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Brief Summary
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In this study the investigators utilized a novel hybrid HIIT (high intensity interval training) exercise training approach, the Hybrid Interval Training (DoIT) workout that combines interval training, resistance exercise training and functional training in order to test the hypothesis that DoIT will be able to: i) reduce body mass, ii) improve body composition and iii) alter energy balance, of previously inactive, overweight/obese women.

Detailed Description
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In a controlled randomized, two-group, repeated measures design, 65 healthy, sedentary, premenopausal overweight or obese women were randomly assigned to one of three groups: (a) a control group (C, N=21) that participated only in measurements, (b) a training group (TR, N=14) that participated in a supervised 40-week DoIT workout exercise training program and (c) a training-detraining group (TRD, N=14). During the first 20 weeks, TR and TRD followed exactly the same training protocol. At the end of this period, TR continued training for 20 more weeks whereas TRD terminated training for 20 weeks (detraining). Anthropometric, metabolic, daily nutritional intake, habitual physical activity and performance measurements were performed in all groups at baseline, at 20 weeks and 40 weeks.

Official Title
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The Effects of a Novel Hybrid Exercise Training Program on Body Composition, Body Weight and Energy Balance in Sedentary Overweight/Obese Women

Conditions
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Circuit-based High Intensity Interval Training, Body Composition, Resting Metabolic Rate, Habitual Physical Activity, Performance

Intervention / Treatment
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* Behavioral: DoIT workout
* Behavioral: DoIT workout - Detraining
* Behavioral: Control - No training


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: (a) were sedentary (<7,500 steps/day; VO2max <30 ml/kg/min), b) premenopausal women aged 30-45 years, c) were overweight or obese class 1 (BMI=25-34.9 kg/m2), d) were non-smokers for ≥6 months before the study, e) not following a diet intervention or using nutritional supplements/medications before (≥6 months) and during the study, f) had no weight loss greater >10% of body mass ≤6 months before the study, g) participated in ≥80% of total exercise sessions, and h) had no symptoms of depression. Exclusion Criteria: a) a recent febrile illness, b) history of muscle lesion, c) lower limb trauma, d) signs, symptoms or diagnosis of serious health complications or physical disability or other medical condition compromising safe participation in exercise training.

Ages Eligible for Study
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Minimum Age: 30 Years
Maximum Age: 45 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: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Control<br>Participated only in measurements at baseline, at 20 weeks and at 40 weeks. | Behavioral: Control - No training<br>* No training was performed during a 40-week period. Participation only in measurements.<br>|
| Experimental: Training<br>Participated in a supervised 40-week DoIT workout exercise training program and in measurements at baseline, at 20 weeks and at 40 weeks. | Behavioral: DoIT workout<br>* A hybrid small-group (5-10 women/session) training modality, that combines interval training, resistance exercise and functional training and performed according to a periodized model of exercise prescription as an alternative approach for weight management. FFIT was performed 3 times/week with 48 hours recovery between sessions for 40 weeks.<br>|
| Experimental: Training-Detraining<br>Participated in a supervised 20-week DoIT workout exercise training program and then entered a 20-week detraining period. They also participated in measurements at baseline, at 20 weeks and at 40 weeks. | Behavioral: DoIT workout - Detraining<br>* A hybrid small-group (5-10 women/session) training modality, that combines interval training, resistance exercise and functional training, performed according to a periodized model of exercise prescription for a 20-week period (3 times/week). Immediately after a 20-week detraining period (no training was performed) was followed.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in body mass |  | At baseline, at 20 weeks and at 40 weeks. | 
| Change in body mass index |  | At baseline, at 20 weeks and at 40 weeks. | 
| Change in waist circumference |  | At baseline, at 20 weeks and at 40 weeks. | 
| Change in hip circumference |  | At baseline, at 20 weeks and at 40 weeks. | 
| Change in waist-to-hip ratio |  | At baseline, at 20 weeks and at 40 weeks. | 
| Change in body fat. | Body fat assessed by whole-body dual-energy X-ray absorptiometry (DXA). | At baseline, at 20 weeks and at 40 weeks. | 
| Change in fat mass | Fat mass assessed by whole-body dual-energy X-ray absorptiometry (DXA). | At baseline, at 20 weeks and at 40 weeks. | 
| Change in fat-free mass | Fat-free mass assessed by whole-body dual-energy X-ray absorptiometry (DXA). | At baseline, at 20 weeks and at 40 weeks. | 
| Change in resting metabolic rate | Measured using a portable open-circuit indirect calorimeter with a ventilated hood system. | At baseline, at 20 weeks and at 40 weeks. | 
| Change in exercise-induced caloric expenditure. | Measured using a portable indirect calorimetry system | At baseline, at 20 weeks and at 40 weeks. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in maximal strength (1RM) | Measured bilaterally on a horizontal leg press. | At baseline, at 20 weeks and at 40 weeks. | 
| Change in maximal oxygen consumption (VO2max) | Assessed by a portable open-circuit spirometry system. | At baseline, at 20 weeks and at 40 weeks. | 
| Change in blood lactate concentration |  | Pre-exercise, during the exercise and post-exercise at baseline, at 20 weeks and at 40 weeks. | 
| Change in habitual physical activity | Seven-day habitual physical activity was assessed by accelerometry | At baseline, at 20 weeks and at 40 weeks. | 
| Change in dietary intake | Assessed using 7-day diet recalls | At baseline, at 20 weeks and at 40 weeks. |