Is Your Diabetes Pill Cancelling Your Workout Gains? New Rutgers Study Warns About Metformin and Exercise

@Nurpur India,
Published on November 20,  2025,
By Pawan

A 16‑week Rutgers trial in adults at risk for diabetes has found that metformin can significantly reduce the usual gains in aerobic fitness, vascular health, and glucose control that people typically get from regular exercise, possibly by altering how mitochondria adapt to training.

 Experts say exercise is still essential, but patients and clinicians may need to rethink how and when metformin is used in active individuals.newatlas+4

                                           

 New Rutgers Study Warns About Metformin and Exercise

       
                                                 

Highlight key points

• Scientists discover metformin may block key exercise benefits: A new Rutgers‑led human trial suggests that metformin can significantly blunt expected gains in fitness, vascular health, and blood sugar control from structured exercise, especially in adults at risk for diabetes.sciencedaily+1​
• Metformin reduced metabolic and cardiovascular improvements from training: Compared with placebo, metformin users showed smaller improvements in aerobic capacity, vascular insulin sensitivity, fasting glucose, and inflammatory markers after 16 weeks of supervised workouts.pharmacytimes+2​
• Participants on metformin saw weaker gains in fitness, blood vessel function, and glucose control: Those exercising without the drug improved VO2max and blood vessel function, while the metformin groups often saw no fitness gains and muted vascular and glycemic changes.technologynetworks+2​
• Mitochondrial effects may explain the interference: Metformin works partly by inhibiting mitochondrial activity, which may dampen the cellular stress and signaling that drive exercise‑induced adaptations in muscles and blood vessels.pmc.ncbi.nlm.nih+2​
• Exercise is still essential, but personalization matters: Experts urge patients not to stop metformin on their own but to discuss individualized plans that balance medication benefits with preserving as much of exercise’s unique health impact as possible.bjsm.bmj+2​

Source: Rutgers University, peer‑reviewed exercise–metformin trials, and major health news coverage.sciencedaily+2

​

Is Your Diabetes Pill Cancelling Your Workout Gains? New Rutgers Study Warns About Metformin and Exercise

Is Your Diabetes Pill Cancelling Your Workout Gains? New Rutgers Study Warns About Metformin and Exercise”sciencedaily+1​

New research from Rutgers suggests metformin, the world’s most prescribed diabetes drug, may blunt key fitness, blood vessel, and blood sugar benefits of exercise by interfering with mitochondrial activity, raising big questions about how best to combine medication and workouts for diabetes prevention.pubmed.ncbi.nlm.nih+2​

What this new metformin–exercise study found

Rutgers researchers recently ran a double‑blind, placebo‑controlled trial in adults with elevated risk for metabolic syndrome to see what happens when you pair metformin with structured exercise training.

 Over 16 weeks, participants were randomly assigned to low‑ or high‑intensity aerobic exercise, combined with either metformin (up to 2,000 mg/day) or placebo.sciencedaily+2

those who exercised with placebo showed clear improvements in aerobic fitness (VO2max), blood vessel function, and markers of glucose and inflammation, confirming the powerful preventive role of regular training. 

By contrast, participants taking metformin saw blunted or even absent gains in several of these key areas, despite doing the same workouts.pharmacytimes+3​

Source: Rutgers University news release and related coverage.rutgers+1​

Key finding: Metformin may block core exercise benefits

The most striking result was that metformin users did not enjoy the usual boost in cardiorespiratory fitness that comes with months of steady exercise. 

In placebo groups, VO2max—a gold‑standard measure of how well the heart, lungs, and muscles use oxygen—rose significantly, but in both low‑ and 

high‑intensity metformin groups, VO2max failed to improve.technologynetworks+2

​

Researchers also saw that metformin dampened improvements in vascular insulin sensitivity, meaning blood vessels did not become as responsive to insulin as they did in people who exercised without the drug.

This pattern suggests that for some cardiometabolic outcomes, adding metformin to training could turn a “double benefit” into a partial trade‑off.empr+3​

Source: Trial report and expert summaries.pubmed.ncbi.nlm.nih+2​

Blood vessel health: gains blunted, not erased

Exercise usually improves how arteries and tiny capillaries respond to blood flow and insulin, helping lower blood pressure and reduce cardiovascular risk.

 In this study, exercise alone improved these measures across intensities, confirming that both moderate and vigorous activity can remodel the vascular system in beneficial ways.pharmacytimes+2

​

When metformin entered the picture, however, these vascular gains were significantly smaller. Measures of conduit artery and microvascular insulin sensitivity improved less in participants taking metformin,

 suggesting the drug interfered with the full range of vessel adaptations that exercise normally triggers.empr+2

​

Source: Journal article on vascular insulin sensitivity after exercise plus metformin.academic.oup+1

​

Glucose control and inflammation: not the full win expected

One might expect that combining metformin—long hailed for its glucose‑lowering power—with exercise would lead to superior blood sugar results. 

Yet the Rutgers team saw that metformin actually attenuated some of the exercise‑induced improvements in fasting glucose and inflammatory markers such as endothelin‑1 and TNF‑alpha.pmc.ncbi.nlm.nih+3

​

Participants who only exercised experienced meaningful drops in fasting blood sugar and pro‑inflammatory molecules, but these benefits were smaller when metformin was on board. 

The results align with earlier work in prediabetes and insulin‑resistant patients where metformin dampened training‑related improvements in insulin sensitivity and glycated hemoglobin.frontiersin+4

​

Source: Study data and prior cardiometabolic trials.pmc.ncbi.nlm.nih+1

​

Fitness and body composition: where metformin falls short

On the fitness front, the new trial adds to a growing pattern: metformin often fails to enhance, and may even blunt, gains in aerobic capacity and muscle performance. 

In healthy older adults and older people with prefrailty, previous research also found that metformin reduced the impact of resistance and aerobic training on strength and endurance outcomes.thelancet+2

​

Body fat changes in the Rutgers study were more nuanced. Exercise alone reduced body fat in most groups, but when metformin was paired with low‑intensity workouts, fat loss was minimal, whereas some earlier work suggested metformin might sometimes aid weight reduction when combined with training.newatlas+2

​

Source: New human trial, prior exercise–metformin interaction studies.thelancet+2

​

Why would a diabetes drug fight exercise? The mitochondrial clue

The big question is mechanistic: how could a drug that improves average glucose control interfere with exercise, one of the best tools for diabetes prevention? 

Rutgers scientists suspect the answer lies in mitochondria—the energy‑producing powerhouses inside cells that adapt strongly to physical training.pmc.ncbi.nlm.nih+2

​

Metformin partly works by inhibiting parts of the mitochondrial respiratory chain, reducing oxidative stress and limiting excess glucose output from the liver. 

However, exercise also relies on mitochondrial signaling and mild, transient oxidative stress to trigger long‑term adaptations like improved endurance and insulin sensitivity, so metformin’s mitochondrial “brake” may blunt these signals and reduce the training response.pmc.ncbi.nlm.nih+2

​

Source: Mechanistic explanations from Rutgers and basic science studies.rutgers+1

​

Mitochondria, exercise, and metformin: what lab models show

Animal and cellular experiments give a deeper look at this tug‑of‑war. In high‑fat‑diet mouse models, exercise training typically restores mitochondrial efficiency, boosts antioxidant defenses, and improves insulin signaling in the brain and muscles.frontiersin+1

​

Metformin in some contexts has also been shown to normalize mitochondrial function and reduce damaging reactive oxygen species, but its chronic inhibition of certain mitochondrial complexes can limit the degree of adaptation seen with repeated exercise stress. 

This complex interaction suggests metformin may be beneficial in specific tissues or disease states while still constraining the full training response in others, such as working skeletal muscle.pmc.ncbi.nlm.nih+1

​

Source: Preclinical work on mitochondrial adaptations to exercise and metformin.frontiersin+1

​

Not all studies agree: a messy evidence landscape

It is important to note that not every study paints metformin as an “exercise blocker.” In some trials involving people with established type 2 diabetes, 

combinations of metformin and exercise have improved glucose metabolism and cardiac function compared with either treatment alone, particularly regarding left ventricular performance and overall cardiopulmonary capacity.bjsm.bmj+1​

Meta‑analyses and randomized trials also show considerable individual variability, with some participants responding well to combined therapy and others seeing blunted gains. 

Differences in age, baseline fitness, disease stage, exercise type (aerobic vs resistance), dose, and timing of metformin may all shape whether it helps or hinders specific outcomes.bjsm.bmj+1

​

Source: Mixed clinical data on combined metformin–exercise treatment.pmc.ncbi.nlm.nih+1

​

What the Rutgers authors actually concluded

The Rutgers group emphasized that exercise remains a cornerstone of diabetes prevention and cardiovascular health but warned that metformin may limit some of the metabolic, vascular, and fitness improvements normally expected from training. 

They stressed that these findings do not mean patients should abandon the drug, especially those with established diabetes who rely on it to control high blood sugar.medicalnewstoday+2

​

Instead, the team called for more personalized approaches that consider how medications and lifestyle therapies interact in real‑world patients. They also highlighted the need to study whether adjusting metformin dose, timing relative to workouts, 

or the type and intensity of exercise might preserve more of the training benefits while maintaining glycemic control.sciencedaily+2

​

Source: Rutgers news release and clinician commentary.medicalnewstoday+1​

What this means if you take metformin and exercise

For people using metformin for prediabetes or type 2 diabetes, these results can sound discouraging, but they should be seen as a prompt for conversation, not a reason to panic.

 Exercise still improves mood, mobility, strength, balance, and many aspects of health that were not measured in the Rutgers trial, and metformin continues to have a strong safety and benefit record as a first‑line diabetes drug.foxnews+2

​

The new findings simply suggest that the combination may not always be additive for fitness, vascular function, and glucose control, especially in early metabolic disease. 

That makes it even more important to work with a clinician who understands exercise physiology and can tailor a plan to your goals, whether that is lowering A1C, boosting endurance, preventing heart disease, or all three.foxnews+3

​

Source: Clinical commentary on the new study and current diabetes guidelines.medicalnewstoday+1

​

Practical questions to ask your doctor

If you are on metformin and committed to regular workouts, consider raising these targeted questions in your next appointment.foxnews+1​

• Do the benefits of metformin clearly outweigh any potential blunting of exercise gains in my specific situation (A1C level, cardiovascular risk, weight, and fitness goals)?pmc.ncbi.nlm.nih+1​
• Are there alternative or additional strategies—such as GLP‑1 receptor agonists, SGLT2 inhibitors, or lifestyle‑first approaches—that might fit my health profile and activity level?bjsm.bmj+1​
• Could adjusting the timing of my metformin dose relative to my workouts reduce its impact on training adaptations, or is that not supported by evidence yet?clinicaltrials+1​

Source: Expert commentary on shared decision‑making in diabetes therapy.medicalnewstoday+1

​

Should anyone stop metformin because of this?

Experts caution strongly against stopping or changing any diabetes medication without medical supervision, even in light of provocative new data like this.

 Abruptly discontinuing metformin can lead to loss of glycemic control, higher blood sugars, and increased risk of complications, especially in people with established diabetes or multiple cardiovascular risks.foxnews+2

​

Instead, the message is to treat exercise as a powerful “drug” in its own right and recognize that drug–exercise interactions matter. 

Future guidelines may evolve to make more nuanced recommendations depending on whether a person is in the prediabetes prevention window, early type 2 diabetes, or later stages of the disease.frontiersin+3

​

Source: News coverage and guideline perspectives.medicalnewstoday+1​

How this challenges older diabetes prevention advice

For years, clinicians were encouraged to pair metformin with exercise on the assumption that combining two proven tools would stack their benefits for people at risk of diabetes. 

The Rutgers data show the math is more complicated: in some cases, one plus one might be closer to one‑and‑a‑half, at least for certain markers like VO2max and vascular insulin sensitivity.pubmed.ncbi.nlm.nih+3

​

This adds to a broader shift in medicine toward appreciating how lifestyle and pharmacologic interventions interact, rather than viewing them as independent levers. 

As more large‑scale trials test drug–exercise combinations head‑to‑head, treatment algorithms for prediabetes and type 2 diabetes may be refined to prioritize strategies that preserve as much of exercise’s unique biology as possible.bjsm.bmj+2

​

Source: Historical and current diabetes prevention recommendations.rutgers+1​

Also Read: Unlock Your Best Chest: The Ultimate Guide to Pectus Excavatum Fitness That Transforms Posture and Strength

What people at risk for diabetes can do right now

If you are in the prediabetes or “high risk” category—the same type of population studied by Rutgers—this research underscores the ongoing importance of lifestyle change. 

Weight management, regular aerobic activity, resistance training, and a diet rich in minimally processed foods remain the most potent tools for delaying or preventing type 2 diabetes onset.clinicaltrials+3

​

Discuss with your provider whether metformin is truly necessary at your current risk level or whether a period of intensive lifestyle intervention alone might be appropriate, given your motivation and support system. 

At the same time, remember that even if metformin modestly blunts some exercise markers, moving your body every day is still far better than remaining inactive in terms of overall health.pmc.ncbi.nlm.nih+3​

Source: Diabetes prevention program data and clinical summaries.frontiersin+1​

Limitations of the Rutgers study

Like any trial, this new research has limits that general readers and patients should keep in mind. 

The study followed a relatively small group of adults for 16 weeks, which is enough time to detect changes in fitness and vascular function but not long enough to track hard outcomes like heart attacks, strokes, or diabetes diagnoses.newatlas+2

​

Participants were a specific at‑risk population, not a cross‑section of all people with type 2 diabetes, so results may not apply equally to every demographic or disease stage. 

The protocol also involved supervised, structured training, which may not reflect real‑world adherence patterns, and did not directly test different metformin timing or dosing strategies.clinicaltrials+2

​

Source: Trial methodology and commentary on external validity.pubmed.ncbi.nlm.nih+1

​

The bigger picture: exercise remains irreplaceable

Even with metformin potentially blunting some specific metrics, no pill can replicate the full spectrum of exercise benefits. 

Regular physical activity improves muscle mass, bone density, mental health, sleep, and functional independence in ways that go far beyond glucose numbers or artery measurements.thelancet+2

​

The new Rutgers findings are best seen as a push to protect those benefits, not a reason to back off the gym. Going forward, the goal will be to design prevention and treatment plans that harness both modern medications and our body’s own adaptive machinery without forcing them to work at cross‑purposes.rutgers+3​

Source: Broad exercise science and clinical perspectives.thelancet+1

Read More information for New Rutgers Study Warns About Metformin and Exercise

---

Tags:#Metformin,#ExerciseScience,#DiabetesPrevention,#FitnessNews,#RutgersResearch,#MetabolicHealth,#CardiovascularHealth,#Mitochondria,#Type2Diabetes,#NurpurFitnessNews,

​

Trusted Source Tag : 

​

1. https://www.rutgers.edu/news/why-your-daily-walk-might-not-work-well-if-youre-metformin
2. https://www.sciencedaily.com/releases/2025/11/251117095648.htm
3. https://www.medicalnewstoday.com/articles/metformin-diabetes-lower-exercise-benefits
4. https://pubmed.ncbi.nlm.nih.gov/41160096/
5. https://newatlas.com/diabetes/diabetes-medication-fitness/
6. https://www.pharmacytimes.com/view/metformin-may-diminish-the-cardiometabolic-benefits-of-exercise
7. https://www.technologynetworks.com/drug-discovery/news/metformin-cancels-out-exercise-benefits-406820
8. https://www.empr.com/news/metformin-blunts-exercise-mediated-increases-in-insulin-sensitivity/
9. https://academic.oup.com/jcem/advance-article-abstract/doi/10.1210/clinem/dgaf551/8276136
10. https://pmc.ncbi.nlm.nih.gov/articles/PMC4906084/
11. https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2020.00519/full
12. https://www.thelancet.com/journals/lanhl/article/PIIS2666-7568(25)00014-5/fulltext?rss=yes
13. https://pmc.ncbi.nlm.nih.gov/articles/PMC6795285/
14. https://bjsm.bmj.com/content/58/23/1452
15. https://www.foxnews.com/health/popular-diabetes-drug-could-block-exercise-benefits-new-study-warns
16. https://clinicaltrials.gov/study/NCT03355469
17. https://www.news-medical.net/news/20251107/Diabetes-drug-blunts-exercise-induced-health-improvements.aspx
18. https://www.instagram.com/reel/DRQJfCbjwBE/
19. https://timesofindia.indiatimes.com/life-style/health-fitness/health-news/diabetes-drug-cancelling-your-workout-gains-study-explains-why/articleshow/125200096.cms
20. https://www.adcesconnect.org/newjerseycoordinatingbody/blogs/geraldine-pierre/2025/11/09/new-research-why-your-daily-walk-might-not-work-as

 

Trending News

Loading...