Obesity (BMI > 35)INCRETraINNCT07761923
Preserving Muscle Mass During Incretin-Induced Weight Loss
A study testing Unilateral Resistance Training in people with Obesity (BMI > 35), run by Karolinska Institutet at 1 site in Sweden.
Trial summary
Treatment with incretin-based obesity medications leads to clinically meaningful weight loss and reduced cardiometabolic risk. However, the weight lost includes not only adipose tissue but also skeletal muscle, which may impair physical function and metabolic health. Read more about this study
- Who is it for?
- Ages 18 to 64 years, women only
- Conditions the study is for
- Obesity (BMI > 35)
- What is being tested?
- Unilateral Resistance Training
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 20 participants
- Where
- 1 siteSweden
- Study dates
- 21 Oct 2026to 1 Jan 2029
- Phase
- Interventional
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 64 years
- Women only
- No healthy volunteers
- Adult
Who may be able to join
- Women aged 18-64 years with obesity, BMI ≥35 kg/m²
- Planned initiation of incretin-based obesity pharmacotherapy as part of routine clinical care.
- Able to participate in supervised unilateral resistance training.
- Able to complete physical function tests.
- Able to attend study visits at the study center.
- Able to provide written informed consent in the Swedish language.
Who cannot join
- Contraindication to magnetic resonance imaging.
- Medical condition preventing resistance training or physical-function testing.
- Medical condition preventing skeletal muscle or adipose-tissue biopsy.
- A weight reduction >5% during the last 3 months.
- Patients diagnosed with any known serious chronic illness, including type 1 or 2 diabetes (or a randomly measured fasting plasma glucose >7 mmol/L).
- Angina pectoris, coronary heart disease or congestive heart failure (NYHA Class III- IV).
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- Severe renal impairment (creatinine clearance (GFR) <30 mL/min).
- Severe hepatic impairment.
- Inflammatory bowel disease.
- Gastroparesis.
- Cancer.
- Chronic obstructive lung disease.
- Severe psychiatric disorders.
- Previous bariatric surgery.
- A history of idiopathic acute pancreatitis.
- The use of medications that cause clinically significant weight gain or loss.
- A family or personal history of multiple endocrine neoplasia type 2 or familial medullary thyroid carcinoma.
- Osteoarthritis, which is judged to be too severe to manage the exercise programme.
- Pregnancy, expecting pregnancy or breast feeding.
- Hypersensitivity to the planned incretin-based medication or any of its excipients.
- Regular exercise training at high intensity (eg, spinning) >2 hours per week.
- Inability to understand the study information in Swedish or provide informed consent.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Sweden1 site
Karolinska University Hospital Huddinge
Stockholm, Stockholm County
Eric B Emanuelsson, PhD, +46730266626, eric.emanuelsson@ki.se
About this study
Official title: Resistance Exercise Training to Preserve Muscle Mass and Physical Function During Incretin-Based Weight Loss
Treatment with incretin-based obesity medications leads to clinically meaningful weight loss and reduced cardiometabolic risk. However, the weight lost includes not only adipose tissue but also skeletal muscle, which may impair physical function and metabolic health.
Resistance training is an effective strategy to maintain or increase skeletal muscle mass during weight loss, but its effects during treatment with incretin-based obesity medications have not been studied. This study will investigate whether unilateral resistance training during incretin-based receptor agonist treatment can preserve or improve skeletal muscle volume. The study will also examine whether training affects muscle strength and fatigue tolerance, body composition, cardiac structure and function, and molecular profiles in skeletal muscle, adipose tissue and blood.
Participants will be women with obesity who are about to start treatment with an incretin-based receptor agonist as part of routine clinical care. During the 13-week intervention, participants will perform supervised unilateral resistance training twice weekly, training one leg while the other leg serves as an internal control. Assessments before treatment start and after 13 weeks include whole-body and cardiac magnetic resonance imaging, blood sampling, skeletal muscle and adipose tissue biopsies, knee-extensor strength and fatigue tests, and questionnaires. An additional intermediate sampling of blood and tissue (week 4-6) will be collected only in participants who consent to an extra visit.
- Conditions
- Obesity (BMI > 35)
- Being tested
- Unilateral Resistance Training
- Keywords
- Obesity, Incretins, Skeletal muscle, Resistance training, Exercise training
- Medical subject headings
- Obesity
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Unilateral Resistance TrainingBehavioural
Supervised resistance training of one leg, two sessions per week for 13 weeks, during incretin-based receptor agonist treatment. The trained leg will be randomly assigned, and the contralateral leg will serve as an internal within-participant control.
| Study group | Role | What they receive |
|---|---|---|
| Incretin treatment combined with unilateral resistance training | Experimental | Participants will initiate incretin-based receptor agonist treatment as part of routine clinical care. The study intervention consists of supervised unilateral resistance training performed twice weekly for 13 weeks. No incretin-based medication is assigned or administered by the study. Receives: Behavioral: Unilateral Resistance Training |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Anterior Thigh Skeletal Muscle Volume
Change in skeletal muscle volume (L) of the anterior thigh muscles, measured by magnetic resonance imaging from baseline to 13 weeks. The primary comparison will be the difference in change from baseline to 13 weeks between the trained leg and the untrained contralateral leg.
Images are analysed by an independent image-analysis service using standardised, automated segmentation, blinded to which leg was trained.
Measured: From baseline to 13 weeks
Secondary outcomes (9)
Change in isometric knee extension strength
Change in lower-limb muscle strength measured using isometric (Nm) knee extension tests.
Measured: From baseline to 13 weeks
Change in isokinetic knee extension strength
Change in lower-limb muscle strength measured using isokinetic (Nm) knee extension tests at 60°/s and 270°/s (Nm).
Measured: From baseline to 13 weeks
Change in muscle fatigue tolerance
Change in peak torque (Nm) during repeated maximal concentric isokinetic contractions at 180°/s, assessed over 30 repetitions. Initial peak torque will be defined as the highest peak torque recorded during the first three repetitions, and final peak torque will be defined as the mean peak torque recorded during the last five repetitions. The decline in torque-generating capacity will be calculated as the absolute and relative decrease from initial to final peak torque.
Measured: From baseline to 13 weeks
Change in whole-body skeletal muscle volume
Change in whole-body skeletal muscle volume (L) measured by magnetic resonance imaging.
Images are analysed by an independent image-analysis service using standardised, automated segmentation.
Measured: From baseline to 13 weeks
Change in total body fat volume
Change in total body fat volume (L) measured by magnetic resonance imaging. Images are analysed by an independent image-analysis service using standardised, automated segmentation.
Measured: From baseline to 13 weeks
Change in liver fat fraction
Change in liver fat fraction (%) measured by magnetic resonance imaging. Images are analysed by an independent image-analysis service using standardised, automated segmentation.
Measured: From baseline to 13 weeks
Change in abdominal subcutaneous adipose tissue volume
Change in abdominal subcutaneous adipose tissue volume (L), measured by magnetic resonace imaging. Images are analysed by an independent image-analysis service using standardised, automated segmentation.
Measured: From baseline to 13 weeks
Change in visceral adipose tissue volume
Change in visceral adipose tissue volume (L) measured by magnetic resonance imaging. Images are analysed by an independent image-analysis service using standardised, automated segmentation.
Measured: From baseline to 13 weeks
Change in skeletal muscle fat infiltration
Change in anterior thigh muscle fat infiltration (%), measured by magnetic resonance imaging. Images are analysed by an independent image-analysis service using standardised, automated segmentation, blinded to which leg was trained.
Measured: From baseline to 13 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted12 Aug 2026
- Study start21 Oct 2026 (estimated)
- Primary completion1 Dec 2028 (estimated)
- Study completion1 Jan 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Obesity (BMI > 35)Studies of the same condition, open and under way.
- More trials run by Karolinska InstitutetThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- All participants undergo incretin-based receptor agonist treatment as part of routine clinical care and complete a 13-week unilateral leg resistance training intervention. One leg is trained and the contralateral leg serves as an internal within-participant control. The trained leg is randomly allocated (dominant or non-dominant). MRI analyses are performed externally by an independent image-analysis service using standardised, automated segmentation; the service has no access to information on which leg was trained.
- Masking
- None (open label)
- Enrolment
- 20 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Karolinska Institutet
- Sponsor type
- University, hospital or other
- Collaborators
- Region Stockholm
- Responsible party
- Principal investigator, Eric Emanuelsson, Karolinska Institutet
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07761923
- Sponsor's protocol ID
- 2026-03191-01
- Acronym
- INCRETraIN
- Status last verified
- Oct 2026
- First submitted
- 30 Jul 2026
- Last updated
- 16 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided: De-identified individual participant data may be made available upon reasonable request after publication, depending on ethical approval, participant consent, Swedish and EU data protection regulations, and institutional policies at Karolinska Institutet and Region Stockholm.