At the University of Copenhagen, 130 adults with severe obesity finished a low-calorie diet, losing about 13.7 kg (30 lb) on average. Researchers then randomly assigned them to a year of exercise, the GLP-1 drug liraglutide, both, or a placebo.
Only the exercisers saw their carotid artery walls thin by 6-7%. Those on liraglutide alone kept the weight off but showed no such vascular improvement, according to the prespecified secondary analysis published in Nature Metabolism in July 2026.
The combined exercise-plus-liraglutide group did better still, adding improvements in endothelial function markers and further weight loss on top of the artery gains.
The trial used liraglutide, an earlier-generation GLP-1 drug sold under the brand name Saxenda. Results may look different with newer, more potent drugs like semaglutide, the active ingredient in Ozempic and Wegovy.
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The measure that moved
Carotid intima-media thickness, the artery-wall measure used in this trial, is a well-established marker of atherosclerosis and is used to estimate a person's risk of future stroke and heart disease. A reduction is generally taken as a favorable signal.
Participants in the two exercise groups trained about 2.5 hours a week, mostly spinning and circuit training. That is a modest volume by fitness standards.
Inflammation fell in exercisers, too
The active groups also showed reduced levels of two inflammatory markers, interleukin-6 and interferon-gamma, both linked to chronic low-grade inflammation in the blood vessels. The medication-only group did not.
The research team's overall conclusion, described in the University of Copenhagen's release, was that medication can help maintain weight loss, but exercise is what delivers the added cardiovascular benefits.
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Signe Torekov, professor at the University of Copenhagen's Department of Biomedical Sciences and one of the researchers behind the study, framed the required dose in everyday terms, saying that swapping a few hours of screen time each week for physical activity was enough to improve cardiovascular health.
What it means for people on GLP-1s
The trial does not argue against GLP-1 drugs. Weight loss on liraglutide still brought metabolic benefits, and adding exercise on top produced the best cardiovascular profile in the study.
But dropping weight on the medication alone left arteries unchanged over the year of follow-up. Anyone taking a GLP-1 for weight loss should talk to their doctor before changing anything, and the researchers' takeaway is simple. Keep moving.
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