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NCT Number: NCT03527446

Acute and Chronic Metabolic Flexibility in Individuals Living With Obesity: The i-FLEX Study

Regular exercise is a cornerstone in the prevention and the management of cardio-metabolic risk factors. Some of the beneficial effect of exercise training occurs through metabolic flexibility' enhancement. Metabolic flexibility is the ability to respond or adapt to conditional changes in metabolic demand, and previous literature has shown that individuals living with obesity have an impaired metabolic flexibility compared to lean individuals. However, there is a lack of empirical evidence on the impact of sprint interval training on metabolic flexibility and whether this translates into clinically meaningful outcomes.

This study will evaluate the impact of 4-week sprint interval training in normal weight individuals as well as individuals living with obesity on acute and chronic metabolic flexibility, irisin secretion and insulin sensitivity.

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Key information

Conditions

Obesity Behavior Body Weight Exercise Glucose Metabolism Disorders Hyperinsulinism Insulin Resistance Insulin Sensitivity Metabolic Diseases Motor Activity Nutrition Disorders Nutritional and Metabolic Diseases Obesity; Endocrine Overnutrition Overweight Pathological Conditions, Signs and Symptoms Signs and Symptoms

Age range

19 year–60 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

University of New Brunswick - Kinesiology

Fredericton, New Brunswick, E3B 5A3, Canada

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Adults (Ages 19-60)
  • Physically inactive for individuals living with obesity (not meeting Canadian Physical Activity Guidelines)
  • Normal Weight (BMI ≥ 18.5 < 25.0 km/m2)
  • Obesity (BMI ≥ 30.0 km/m2)

Exclusion criteria

  • Individuals with Type 2 Diabetes.
  • Individuals with impaired glucose tolerance.
  • Individuals living with obesity that partake in regular exercise training / meet the Canadian Physical Activity Guidelines.
  • Individuals with a condition or injury that may impact the ability to perform exercise or may be worsened by exercise.
  • Individuals currently being treated with corticosteroids or atypical antipsychotics, as these agents significantly influence carbohydrate metabolism.
  • have experienced >10% weight loss or enrolled in weight loss program within six months of enrolment.
  • require use of medication(s) known to affect insulin sensitivity or secretion within the last 30 days.
  • Medication(s) known to cause weight gain.
  • weight loss medication(s).

Treatment and study plan

Sprint Interval Training

Behavioral

The 4-week sprint interval intervention will consist of a work-rest ratio of four 30-s intervals of exercise at maximal capacity and 4-min of passive recovery at 50% of maximal capacity between intervals. There will be three sessions per week.

Primary outcomes

  1. Change in Metabolic Flexibility

    Time frame: Baseline and post-intervention (4 weeks)

    Chronic and acute metabolic flexibility will be quantified from the respiratory quotient (RQ) at rest and from the respiratory exchange ratio (RER) during a 4-6 minutes steady rate exercise bout.

  2. Change in Insulin Sensitivity

    Time frame: Baseline and post-intervention (4 weeks)

    Insulin sensitivity will be measure with the Matsuda Index

Secondary outcomes

  1. Change in Irisin

    Time frame: Baseline and post-intervention (4 weeks)

    This hormone will be quantified in the plasma during one acute session of exercise.

Sponsors and collaborators

Lead sponsor

University of New Brunswick

Other

Registry information

Official study title

Sprint Interval Training: Insulin Sensitivity and Acute-Chronic Metabolic Flexibility in Individuals Living With Obesity: The i-FLEX Study

Acronym: i-FLEX

Important dates

Study start
2018
Primary completion
2020
Study completion
2020
First posted
May 17, 2018
Registry last updated
Mar 25, 2020

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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