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Exercise Training and Fitness in Severe Obesity (INTFMOBE)

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ClinicalTrials.gov Identifier: NCT02254200
Recruitment Status : Completed
First Posted : October 1, 2014
Last Update Posted : July 21, 2015
Sponsor:
Collaborator:
University of Lausanne
Information provided by (Responsible Party):
Istituto Auxologico Italiano

Brief Summary:

Obesity is commonly associated with insulin resistance and hyperinsulinemia, which seem to be linked with an impaired ability to oxidize lipids, particularly in class III obese individuals [Body Mass Index (BMI): > 40 kg*m-2]. Exercise training is an effective strategy to improve insulin sensitivity and to reduce the risk of type 2 diabetes.

This study aimed to compare the effects of two different 2-wk-long training modalities [continuous at the intensity eliciting the maximal fat oxidation (Fatmax) versus adapted high intensity interval training (HIIT)] on aerobic and metabolic fitness of class II and III obese men. It was hypothesized that, because of the nature of HIIT in the stimulation of rapid changes, aerobic fitness, fat oxidation rates during exercise and insulin sensitivity would be improved to a greater extent when adapted HIIT compared to Fatmax training.


Condition or disease Intervention/treatment Phase
Obesity Other: Fatmax group Other: HIIT group Not Applicable

Detailed Description:

Obesity is commonly associated with insulin resistance and hyperinsulinemia, which seem to be linked with an impaired ability to oxidize lipids, particularly in class III obese individuals [Body Mass Index (BMI): > 40 kg*m-2] (1). Exercise training is an effective strategy to improve insulin sensitivity and to reduce the risk of type 2 diabetes (2). It has been suggested that 8 (3) or 10 wk (4) of an individualized moderate exercise training program at intensity (Fatmax) that elicits maximal fat oxidation (MFO) may significantly increase the fat oxidation rates (FORs) during exercise; it may also increase the muscle oxidative capacity in overweight and class I obese men. The effects of an individualized Fatmax training program of a shorter duration have never been investigated.

High-intensity interval training (Wingate-based HIIT) has been shown to induce similar adaptations as traditional training at a moderate intensity following 6 wk of training in healthy adults despite the lower training volume (5). This suggests that HIIT may be a time-efficient alternative (6). Recently, HIIT was also reported to rapidly induce adaptations that are linked to improved health-related outcomes in sedentary and overweight/obese individuals (7, 8).

This study aimed to compare the effects of two different 2-wk-long training modalities [continuous at the intensity eliciting the maximal fat oxidation (Fatmax) versus adapted high intensity interval training (HIIT)] on aerobic and metabolic fitness of class II and III obese men. It was hypothesized that, because of the nature of HIIT in the stimulation of rapid changes, aerobic fitness, fat oxidation rates during exercise and insulin sensitivity would be improved to a greater extent when trained with adapted HIIT compared to Fatmax training.

A group of twenty obese men (BMI≥35 kg*m-2) will be assigned to Fatmax group or to adapted HIIT group. Both groups will perform 8 cycling-sessions matched for mechanical work spread over 14 days [40-50 min continuous exercise at ~60-70% of the maximal heart rate (Fatmax) or 10x60-s cycling intervals a ~90% maximal heart rate interspersed with 60-s recovery (HIIT)]. Aerobic fitness and fat oxidation rates (FORs) during exercise will be assessed prior to and following the training with a maximal incremental test. Blood samples will also be drawn to determine hormones and plasma metabolites levels. Insulin sensitivity was assessed by the homeostasis model assessment of insulin resistance (HOMA).

The experimental design will consist of the following: 1) maximal ramp incremental test, to determine peak power output of each subject. 2) pre training test with blood samples, maximal incremental test (Incr) to determine the whole-body fat oxidation kinetics and Fatmax in the first phase (IncrP1) and the maximal parameters in the second phase (IncrP2) of the test. 3) 2-wk training intervention, Fatmax or HIIT and 4) post-training test, control maximal incremental test with blood samples.

A 3-way repeated-measures ANOVA (time x group x exercise intensity) will be performed to compare the investigated variables.


Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 19 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: Effect of Short-term High-intensity Interval and Fatmax Training on Aerobic and Metabolic Fitness in Obese Subjects
Study Start Date : January 2013
Actual Primary Completion Date : December 2013
Actual Study Completion Date : January 2014

Arm Intervention/treatment
Experimental: Fatmax group
Group who performed a continuous training program at the intensity eliciting the maximal fat oxidation
Other: Fatmax group
For the Fatmax group each session will consist of 40-50 min of continuous exercise with an intensity that corresponded to the individual Fatmax (moderate intensity)

Experimental: HIIT group
Group who performed a continuous training program with high intensity interval
Other: HIIT group
For HIIT group, each session will consist of 10x60-s cycling intervals interspersed with 60-s of recovery. The workloads will be selected to elicit a heart rate of ~90% maximal heart rate during the intervals with a pedal rate of 90-100 revolutions.min-1, whereas during recovery, the participants will be allowed to pedal against a resistance of 50 W




Primary Outcome Measures :
  1. Maximal Oxygen consumption (VO2 max) [ Time Frame: After two-wk-long of Fatmax or HIIT traning ]
    VO2 max at incremental test performed at the end of Fatmax or HIIT training period

  2. Fat oxidation rates (FORs) [ Time Frame: After two-wk-long of Fatmax or HIIT traning ]
    FORs at incremental test performed at the end of Fatmax or HIIT training period


Secondary Outcome Measures :
  1. HOMA-IR [ Time Frame: After two-wk-long of Fatmax or HIIT traning ]
    Insulin sensitivity assessed by homeostasis model assessment of insulin resistance (HOMA-IR) at the end of Fatmax or HIIT training period

  2. Non-esterified fatty acid (NEFA) [ Time Frame: After two-wk-long of Fatmax or HIIT traning ]
    Resting NEFA at the end of Fatmax or HIIT training period

  3. Insulin [ Time Frame: After two-wk-long of Fatmax or HIIT traning ]
    Resting Insulin at the end of Fatmax or HIIT training period



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Ages Eligible for Study:   20 Years to 45 Years   (Adult)
Sexes Eligible for Study:   Male
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • BMI ≥ 35 kg*m-2

Exclusion Criteria:

  • Hypertension (blood pressure > 130/90)
  • Impaired fasting glucose (> 6.1 mmol*L-1)
  • Type 2 diabetes
  • Abnormal ECG readings at rest

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT02254200


Locations
Italy
Istituto Auxologico Italiano, Ospedale San Giuseppe
Verbania, VB, Italy, 28921
Sponsors and Collaborators
Istituto Auxologico Italiano
University of Lausanne
Investigators
Principal Investigator: Stefano Lanzi, MSc University of Lausanne, Department of Physiology
Study Director: Alberto Salvadori, MD Istituto Auxologico Italiano, Pulmonary Rehabilitation Department
Principal Investigator: Franco Codecasa, MD Istituto Auxologico Italiano, Pulmonary Rehabilitation Department
Study Chair: Mauro Cornacchia, MD Istituto Auxologico Italiano, Pulmonary Rehabilitation Department
Study Director: Davide Malatesta, PhD University of Lausanne, Institute of Sport Sciences
Study Chair: Paolo Fanari, MD Istituto Auxologico Italiano, Pulmonary Rehabilitation Department

Publications:

Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: Istituto Auxologico Italiano
ClinicalTrials.gov Identifier: NCT02254200     History of Changes
Other Study ID Numbers: 06C301
First Posted: October 1, 2014    Key Record Dates
Last Update Posted: July 21, 2015
Last Verified: July 2015

Keywords provided by Istituto Auxologico Italiano:
exercise
fat oxidation
indirect calorimetry
insulin sensitivity
weight management

Additional relevant MeSH terms:
Obesity
Overnutrition
Nutrition Disorders
Overweight
Body Weight
Signs and Symptoms