Clinical trial NCT03527446: Acute and Chronic Metabolic Flexibility in Individuals Living With Obesity: The i-FLEX Study
Official title: Sprint Interval Training: Insulin Sensitivity and Acute-Chronic Metabolic Flexibility in Individuals Living With Obesity: The i-FLEX Study
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Obesity
Obesity; Endocrine
Insulin Sensitivity
Exercise
Keywords: Metabolic flexibility
Insulin sensitivity
Sprint interval training
Obesity
Exercise intensity
Lead sponsor: University of New Brunswick
Sponsor class: OTHER
First posted: 2018-05-17
Enrollment: 34
Sex: ALL
Minimum age (years): 19
Maximum age (years): 60
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: NON_RANDOMIZED
Intervention model: PARALLEL
Intervention model description: Individuals living with obesity (BMI ≥ 30 km/m2; n=15) as well as normal weight (BMI ≥ 18.5 \< 25.0 km/m2; n=15) adults (aged between 19 to 60 years) will be recruited to participate in the study. All participants will be asked to come in for a total of two visits and participate in a 4-week intervention.
Primary purpose: PREVENTION

Brief summary: 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.


Eligibility criteria: 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).

Primary outcomes:
measure: Change in Metabolic Flexibility
timeFrame: Baseline and post-intervention (4 weeks)
measure: Change in Insulin Sensitivity
timeFrame: Baseline and post-intervention (4 weeks)
Secondary outcomes:
measure: Change in Irisin
timeFrame: Baseline and post-intervention (4 weeks)
Other outcomes:
Locations:
city: Fredericton
country: Canada
facility: University of New Brunswick - Kinesiology
state: New Brunswick
Study officials:
affiliation: University of New Brunswick
name: Martin Senechal, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Muoio DM. Metabolic inflexibility: when mitochondrial indecision leads to metabolic gridlock. Cell. 2014 Dec 4;159(6):1253-62. doi: 10.1016/j.cell.2014.11.034.