Back and Chest Muscle Quality Is Linked to Heart Attack Risk, Study Finds

Back and Chest Muscle Quality Is Linked to Heart Attack Risk

Back and chest muscle quality is linked to heart attack risk, having high-quality back and chest muscles might do more than support mobility and strength—it may also reveal clues about your heart health, according to a recent study.

For the study, which was published in the journal Radiology, researchers used AI tools to find that people with denser chest and back muscles were also less likely to have a heart attack or die over the next decade.

The finding doesn’t prove that dense muscle in these areas prevents heart attacks, but it uncovers an association between muscle quality and heart-protective benefits.

What Did the Study Find?

Researchers set out to examine the routine CT scans of the heart and blood vessels of 1,722 adults with an average age of about 58.

“We wanted to know if other information that is available on routine heart scans could be useful for patients,” Michelle Williams, MBChB, PhD, a professor of cardiovascular imaging at the University of Edinburgh and the primary author of the study, told HEALTH.

An AI tool called “TotalSegmentator” assessed the scans, mapping 25 body systems, including muscle, bone, fat, lungs, and heart chambers. After a 10-year follow-up, researchers checked whether certain body compositions could predict who died or who had a heart attack.

One finding stood out: Muscle quality—a measure of how much fat muscle tissue contains—in participants’ torsos predicted heart attacks. Specifically, higher torso muscle density was associated with a roughly 31% lower heart attack risk for every 10-point increase in muscle density. About 39% of people with denser torso muscles had a lower mortality risk over 10 years.

In contrast, people with lower muscle density had higher risks of both death and heart attack. People with coronary artery disease also tended to have more fat around their torsos and less dense muscle.

Notably, how much muscle someone had didn’t matter much. “It was the quality of muscle that counted,” said Karly Mendez, PhD, a senior human performance specialist and exercise physiologist at Memorial Hermann Sports Medicine Institute.

What Exactly Is “Muscle Quality?”

Higher-quality muscle will look “clean” on a CT scan, said Mendez, meaning it will have less fat infiltration, or fat stuck between and within muscle fibers.

“This difference matters because fat inside muscle is tied to insulin resistance, inflammation, and reduced physical function,” Mendez said. In other words, muscles with less fat infiltration are more metabolically active and functional.

People who exercise regularly tend to have higher muscle quality because “muscles become more dense if they are used more,” Williams said.

Density is different from muscle mass, however, which refers to the size and weight of the body’s muscles.

What Should You Make of the Findings?

The study findings were promising, but the research only found an association between muscle quality and heart attacks—not causation.

Denser muscles could simply be a marker of people who exercise regularly, eat well, and maintain a healthier body composition, all of which could also lower heart attack risk.

Similarly, lower muscle density may be a symptom of other heart attack risk factors, not a driver of them, said Srinivas Prasad, MD, an interventional cardiologist at Orlando Health. Risk factors could include poor overall health, aging, inactivity, underlying illness, inflammation, or metabolic issues, Mendez said.

In general, more research is needed before muscle density can be considered a cardiovascular risk factor in clinical practice.

How Can You Improve Muscle Quality?

Still, reducing fat within your muscles may have broader health benefits. Experts recommend whole-body strength training to improve muscle quality rather than focusing solely on chest-specific exercises.

“Progressive resistance training is the most solid, evidence-backed way to build denser muscle over time,” Mendez said. This typically involves two to three sessions targeting major muscle groups and gradually adding weight and resistance over time.

Not only can strength training improve muscle density, but a robust body of past research shows it may improve other heart health markers, such as blood pressure, cholesterol levels, and insulin sensitivity.

Prasad recommends finding exercises you enjoy and sticking with them long-term. “Consistency beats optimization,” he said.

Other ways to improve muscle quality include:

• Eating enough protein to support muscle repair and growth
• Cardio, like walking, running, or swimming
• Getting enough sleep and reducing stress

Keep in mind that improving muscle quality takes time. “It’s a long game,” Mendez said, “not something you fix in a few weeks.”