Overweight and Obesity
Conditions
Brief summary
This human intervention study will test if 12 weeks of supervised HIIT-based intervention improves skeletal muscle NOGD capacity in obese subjects.
Detailed description
19 overweight-obese (BMI =\> 27kg/m2), sedentary females and males aged 45-75yr will be enrolled in this study. Participants will train 3 times/week under supervision during 12 weeks. Before, after and during this 12-week training period, there will be multiple metabolic measurements.
Interventions
BEHAVIORALHigh-intenstiy interval training
High-intensity interval training is a training of 30 minutes involving 10 bouts of 1 minute high intensity cycling (80-90% of maximum heart rate) interspersed by 2 minutes rest.
Sponsors
Netherlands Organisation for Scientific Research
Maastricht University
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
PREVENTION
Masking
NONE
Intervention model description
1 group of participants that performs 12 weeks of HIIT with metabolic measurements before and after this training period
Eligibility
Sex/Gender
ALL
Age
45 Years to 75 Years
Healthy volunteers
Yes
Inclusion criteria
* Signed informed consent * Age 45 - 75 years old * Overweight to obese (BMI =\> 27kg/m2) * Sedentary - subjects do not perform any regular physical activity weekly(\<3 times per week, \<150 min/week).
Exclusion criteria
* Unstable body weight (weight gain or loss \> 3 kg in the past three months) * Participation in an intensive weight-loss program or in vigorous exercise program during the last year before starting the study. * HbA1c \> 6.5% and glucose clearance rate \>350 ml/kg/min (by OGTT). * Previously diagnosed with type 2 diabetes * Active cardiovascular disease. This will be determined by the questionnaires and by screening on medication. * Use of beta-blockers * Anticoagulant therapy * Systolic blood pressure \>160 mmHg or diastolic blood pressure \>100 mmHg * Abuse of alcohol (\> 3 units (1 unit = 10 gr ethanol) per day) * Any contra-indication to Magnetic Resonance Imaging (MRI) scanning * Participation in another biomedical study within 1 month before the first study visit, which may interfere with the outcomes of the present study. * Use of any medication affecting the glucose homeostasis and whole body metabolism or diseases that may significantly interfere with the main aim of the study. * Chronic renal dysfunction (creatinine \>2 increased (normal value 64-104 µmol/l) * Subjects who do not want to be informed about unexpected medical findings during the screening / study, or do not wish that their physician is informed, cannot participate in the study. * Subjects will be included only when the dependent medical doctor of this study approves participation after evaluating all data obtained during the screening.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Non-oxidative glucose disposal | 9 hours | Measured during a 2-step hyperinsulinemic-euglycemic clamp combined with indirect calorimetry |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Skeletal muscle glycogen content | 1 hour | Assessed from skeletal muscle biopsies |
| Skeletal muscle insulin sensitivity | 9 hours | Measured during a 2-step hyperinsulinemic-euglycemic clamp |
| 24 hour glycaemic profile | 48 hours | continuous glucose monitor |
| Metabolic Flexibility during exercise assessed by indirect calorimetry. | 30 minutes | Participants will undergo a standardized cycling test at low, moderate and high intensity (30%-50%-70%) during 10 minutes each. Throughout the test, indirect calorimetry will be performed in order to measure changes in substrate oxidation during exercise. |
| Ectopic Fat accumulation in the liver assessed by magnetic resonance spectroscopy. | 1 hour | Participants will undergo a magnetic resonance spectroscopy scan from which hepatic fat content will be quantified. In the 1H-MRS spectra, the water signal, that is dominating the proton spectra, will be suppressed using frequency-selective pre-pulse and the spectra will be fitted to quantify the lipid peak. A separate spectrum will be measured without water suppression to quantify the unsuppressed water signal. The CH2/Water ratio will be used as parameter of intrahepatic lipid content. |
| Maximal Acetylcarnitine formation in the upper-leg at rest and after exercise assessed by Magnetic Resonance Spectroscopy Scan | 1 hour | Magnetic resonance imaging (MRI) will be used to guide the spectroscopy measurements and fine shimming will be performed to optimize the magnetic field homogeneity within the region of interest. A volume of interest will be selected within the m. vastus lateralis from the MRI images and the 1H-MRS spectra will be acquired from this region of interest. The intensity of the creatine signal will be used as internal reference. |
| Skeletal muscle mitochondrial function assessed by Magnetic Resonance Spectroscopy Scan using 31P-MRS methodology, based on the phosphocreatine (PCr) recovery kinetics after exercise. | 1 hour | The participant is positioned in the scanner with a home-built exercise device to perform consecutive knee-extensions, in which the participant has to lift a weight whilst laying in the scanner (50-60% max leg capacity of the subjects) for 5 minutes. Scout images of the upper leg are acquired and fine-tuned shimming is applied. Before, during and after exercise, spectra are acquired every 4 seconds. The restoration of PCr is driven almost purely by oxidative metabolism, the time to restore the normal amount reflects mitochondrial function (a faster restoration time means better mitochondrial function). |
Other
| Measure | Time frame | Description |
|---|---|---|
| Effect of consumption of insulinogenic, CHO-rich drink post-exercise | 12 weeks | Investigate whether the consumption of a insulinogenic, CHO-rich drink post-training prevention adverse effects related to blood glucose fluctuation while maintaining the effects of 12 weeks of HIIT on NOGD. |
Countries
Netherlands
Outcome results
None listed