Long-Term Effects of Semaglutide on Body Composition and Performance in Running

What Was Tested

In this not phased trial, researchers set out to test Semaglutide.

This randomized placebo-controlled parallel intervention study aims to investigate the long-term effects of semaglutide on body composition, muscle mass, volume and function, running economy, and performance as well as on hormonal markers in well-trained male and female runners.

It had two arms (groups): Semaglutide (experimental) and Placebo (placebo comparator).

Participants will receive semaglutide treatment for 12 weeks. This will be followed by a 4-week follow-up period without treatment.

Participants will receive placebo treatment for 12 weeks. This will be followed by a 4-week follow-up period without treatment.

The registry classes the interventions as drug.

More on the Plan

Furthermore, participants will complete a follow-up period consisting of 4 weeks without treatment.

Before and after the intervention period as well as the follow-up period, participants will complete 2 experimental days (6 experimental days in total).

On experimental days, change in body composition, with a particular focus on muscle mass, will be assessed using DXA scans and ultrasound imaging of v. lateralis.

In addition, specific performance tests (200-m, 3-km, 10-km) and running economy, as well as hormonal markers in serum and urine will be measured.

Who Took Part

The registry lists 41 planned participants were the target.

It was open to people of any sex aged from 18 years up to 45 years.

Healthy volunteers could join, not only people with the condition.

Examples of who could join: Healthy experienced triathletes or distance runners (training history +5 years and weekly training volume \>10 h/week). Aged 18 to 45 years. Body mass index (BMI) between 21.0-26.0 kg/m2.

The full record lists 3 inclusion and 6 exclusion criteria; among the exclusions: chronic use of medication (except for occasional use of analgesics or antihistamines); chronic disease (e.g. diabetes, disordered eating behavior (ede-q \>2.5 for females and 1.7 for males)); abnormal kidney function, or ecg abnormalities.

How the Study Was Run

It was run as a randomized, parallel-group and triple-blind study.

Because people in this Semaglutide study were split into groups at random, differences between the groups are less likely to reflect who happened to join each one.

The Semaglutide group and the comparison group ran side by side rather than switching.

Neither the participants nor the staff measuring them knew who was on Semaglutide, so expectations could not easily colour the readings.

Those kept unaware of assignments: participant, care provider and investigator.

It started in 2026-10-14 with completion listed for 2027-12-30.

It ran at 1 site in Denmark.

Its stated primary purpose is basic science.

What Was Measured

The main thing measured (primary outcome): Change in total lean mass measured by dual-energy X-ray absorptiometry (DXA).

It also tracked 4 secondary outcomes, for example Change in muscle thickness measured by ultrasonography, Change in running performance, Change in maximal voluntary isometric quadriceps contraction torque and Change in one-repetition maximum (1RM) leg press strength.

What This Means in Plain Language

Put simply, this is a not phased, randomized trial of Semaglutide in 41 people.

Its status is not yet recruiting; no results are posted to the registry yet, so nothing here describes outcomes.

More context: the Semaglutide compound page, all human trials.