This project will determine the independent and combined effects of high intensity interval training and time-restricted eating on blood sugar regulation among women in reproductive-age who have overweight or obesity. The intervention period will be seven weeks. Before and after the intervention, blood sugar regulation, body composition and physical fitness will be measured and compared between groups who are doing either high intensity interval training, time-restricted eating, both high intensity interval training and time-restricted eating, or who are in a control group. Physical activity, sleep quality, continuous glucose monitoring, adherence to the interventions and hunger/satiety will also be measured.
In a follow-up study, we will invite randomized participants to come in for new assessments of physical fitness, body composition and fasting blood samples, and they will be asked to complete questionnaires about adherence to the interventions two years after intervention-end. The first participants will come in to the laboratory for the two-year follow up in November 2021.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
NONE
Enrollment
131
Three weekly, supervised exercise sessions with high intensity. Each session will last for 30-45 minutes. Intervention period will be seven weeks.
Restricted daily window of caloric intake to maximum 10 hours. Intervention period will be seven weeks.
Department of circulation and medical imaging , NTNU
Trondheim, Norway
Glycaemic control
Total area under the plasma glucose curve over two hours after a 75 g oral glucose tolerance test
Time frame: From baseline to after 7 weeks intervention
Insulin sensitivity
Insulin sensitivity estimated by homeostatic model assessment for insulin resistance (fasting serum insulin concentration (μU/mL) x fasting plasma glucose levels (mmol/L)/22.5)
Time frame: From baseline to after 7 weeks intervention
Insulin levels after ingestion of glucose
Total area under the serum insulin two hours after a 75 g oral glucose tolerance test
Time frame: From baseline to after 7 weeks intervention
Cardiorespiratory fitness
Peak oxygen uptake at a maximum effort exercise test, measured in mL/min/kg and L/min
Time frame: From baseline to after 7 weeks intervention
Body mass
In kg
Time frame: From baseline to after 7 weeks intervention
Body fat mass
In kg
Time frame: From baseline to after 7 weeks intervention
Body fat percentage
In percent of total body mass
Time frame: From baseline to after 7 weeks intervention
Fat-free body mass
In kg
Time frame: From baseline to after 7 weeks intervention
Fat-free body mass percentage
In percent of total body mass
Time frame: From baseline to after 7 weeks intervention
Systolic blood pressure
Average of three measurements, in mmHg
Time frame: From baseline to after 7 weeks intervention
Diastolic blood pressure
Average of three measurements, in mmHg
Time frame: From baseline to after 7 weeks intervention
Resting heart rate
Average of three measurements, in beats/min
Time frame: From baseline to after 7 weeks intervention
Cholesterol in blood
Total fasting cholesterol in blood
Time frame: From baseline to after 7 weeks intervention
High density lipoprotein cholesterol in blood
Fasting high density lipoprotein cholesterol i blood
Time frame: From baseline to after 7 weeks intervention
Low density lipoprotein cholesterol in blood
Fasting low density lipoprotein cholesterol i blood
Time frame: From baseline to after 7 weeks intervention
Triglycerides in blood
Fasting low density lipoprotein cholesterol i blood
Time frame: From baseline to after 7 weeks intervention
Average glucose levels
Glycated haemoglobin (HbA1c)
Time frame: From baseline to after 7 weeks intervention
Insulinemia
Fasting insulin in blood
Time frame: From baseline to after 7 weeks intervention
24 hour glycaemic control
Average interstitial glucose levels during 24 h, area under the curve
Time frame: From baseline to the last 14 days of the intervention period
Postprandial glycaemic control
Average interstitial glucose levels 3 hours after the first meal of the day, area under the curve
Time frame: From baseline to the last 14 days of the intervention period
Nocturnal glycaemic control
Average interstitial glucose levels from 23:00 h to 06:00 h
Time frame: From baseline to the last 14 days of the intervention period
Self-reported physical activity
International Physical Activity Questionnaire
Time frame: From baseline to after 7 weeks intervention
Measured physical activity
Measure by Sensewear activity monitor
Time frame: From baseline to the last 14 days of the intervention period
Sleep
Self-reported: Pittsburgh Sleep Quality Index
Time frame: From baseline to after 7 weeks intervention
Chronotype
Self-reported: Hornestberg Morningness Eveningness Questionnaire
Time frame: From baseline to after 7 weeks intervention
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