Does Metformin Minimize Muscle and Ability to Crush Cardio? – Muscle and fitness

If you are one of the more than 150 million people worldwide who use metformin to do so improvement of insulin sensitivity and enjoys exercising, you might be surprised to learn that a new study suggests that the drug may weaken some of the important benefits of exercise.

Here’s what you need to know.

The study, led by a team from Rutgers Universityappears to show that metformin may reduce exercise-based improvements in several areas, such as vascular health and blood sugar control. While the traditional advice has been to combine metformin with exercise for a two-pronged approach to fighting type 2 diabetes, Rutgers researchers say the evidence is not that simple.

‘Most healthcare providers assume that one plus one equals two’ said Steven Malin, a professor and lead author of the study. “The problem is that most evidence shows that metformin reduces exercise benefits.”

How was this Metformin study conducted?

72 adults at risk for metabolic syndrome (a variety of conditions that increase the risk of diabetes and heart disease) were divided into four groups:

• People doing intense exercise on a placebo
• People who do high-intensity exercise on metformin
• People performing low-intensity exercise on a placebo
• People performing low-intensity exercise on metformin

Over the course of 16 weeks, scientists monitored changes in blood vessel function under insulin stimulation to help dilate blood vessels and release oxygen, hormones and nutrients after meals.

What were the results?

Exercise alone was shown to improve vascular insulin sensitivity, allowing greater blood flow to the muscles, but in the groups taking metformin the benefits were reduced. Metformin reduced aerobic fitness gains and even reduced its positive effects on inflammation and fasting glucose levels in those who combined the drug with exercise. “Blood vessel function improved with physical training, regardless of intensity,” says Professor Malin. “Metformin weakened that observation, suggesting that one type of exercise intensity is also not better with the drug for blood vessel health.”

These results are disappointing for those who take metformin and enjoy exercising, because exercise lowers blood sugar levels and improves physical function. “If you exercise and use metformin and your blood glucose does not drop, then that is a problem,” says Professor Malin. “People who took metformin also did not become fitter. This means that their physical function does not improve and that can pose long-term health risks.”

The reasons for these effects are not yet fully understood, but it is thought that metformin could block parts of the mitochondria and the system that normally regulates blood sugar levels and oxidative stress.

So what should we make of these findings? Professor Malin says people shouldn’t stop taking metformin to make gains, or stop exercising, but it does mean the medical community will need to come up with future strategies to improve the response to exercise while taking the drug. “We need to figure out how best to recommend exercise with metformin,” concluded Professor Malin.

Previous experiments have suggested this that the timing of metformin intake could help. One study found that moderate-intensity exercise in the morning combined with metformin before breakfast was more effective at lowering blood sugar levels for several weeks compared to taking metformin after breakfast. “We also need to consider how other medications interact with exercise,” Malin said.