Short Bursts of Intense Exercise May Slash Type 2 Diabetes Risk, Study Finds

A new study suggests that how hard you exercise matters just as much as how long you exercise when it comes to preventing serious diseases.

For years, health guidelines have focused mostly on the total amount of exercise people should get each week. The standard recommendation for adults is about 150 minutes of moderate activity. But these guidelines often don’t say much about how intense that exercise should be.

Now, research published in the European Heart Journal finds that people who do even small amounts of vigorous activity each day may have a much lower risk of developing eight major diseases.

“In our study, even a small proportion of vigorous activity—just over 4% of total activity, which may translate to only a few minutes per day—was associated with meaningful health benefits,” said Dr. Minxue Shen, a professor at Xiangya School of Public Health in China and co-author of the study.

Vigorous exercise doesn’t have to mean extreme workouts. It simply means you’re breathing hard and can only speak a few words at a time. Everyday tasks like carrying heavy groceries or walking quickly up stairs can count.

Compared to people who did no vigorous exercise at all, those who did had a lower risk of death, heart disease, type 2 diabetes, dementia, and other conditions. For some diseases, both total exercise and intensity mattered. But for others, like immune-related conditions, the benefit came almost entirely from how hard people worked out.

The study is observational, meaning it doesn’t prove that exercise intensity directly causes lower disease risk. But the findings line up with other research suggesting that intensity is a key part of staying healthy.

Researchers looked at data from the UK Biobank, which tracks health information for half a million adults. They focused on two groups: about 96,000 people who wore fitness trackers for a week, and about 375,000 people who reported their own activity levels.

Participants were between 56 and 62 years old on average, and just over half were women. The tracker group was followed for about nine years, and the self-report group for over 14 years. During that time, researchers tracked who developed any of eight chronic conditions: type 2 diabetes, dementia, chronic kidney disease, atrial fibrillation, immune-mediated inflammatory diseases (like rheumatoid arthritis), fatty liver disease, heart disease, and chronic respiratory disease (like COPD).

In both groups, people who did more vigorous exercise had lower risks of disease, even when their total amount of exercise was the same.

“This study moves beyond the simple question of ‘How much exercise?’ and really examines how the intensity of that exercise matters,” said Dr. Denice Ichinoe, an assistant professor at the Kirk Kerkorian School of Medicine in Las Vegas who was not involved in the study. “Moving more is essential, but how hard you move can further influence long-term health outcomes.”

The more vigorous activity people did, the greater the benefit. But the effect leveled off once vigorous activity made up about 4% to 5% of total activity, suggesting that extreme amounts aren’t needed.

In the fitness tracker group, people who got more than 4% of their activity from vigorous exercise had about a 31% lower risk of major heart problems, a 60% lower risk of type 2 diabetes, and a 63% lower risk of dementia compared to those who did no vigorous exercise.

Higher-intensity activity was linked to roughly a 60% lower risk of type 2 diabetes, a 63% lower risk of dementia, and a 46% lower risk of death. These benefits were seen even at low levels of vigorous activity.

Different diseases responded differently to exercise. For immune-related diseases and dementia, the risk reduction came almost entirely from intensity. For metabolic conditions like diabetes, both intensity and total activity played a role.

Some people may find the idea of vigorous exercise overwhelming, but there are simple ways to start. Dr. Ichinoe recommends beginning with a regular routine of moderate exercise on most days, then adding one or two sessions of more intense activity each week. Choosing activities you enjoy is key for sticking with it. A simple way to check intensity is the “talk test”: moderate activity lets you talk, but vigorous activity means you can only say a few words at a time.

Older adults who aren’t regularly active, especially those with balance issues, should check with a doctor before starting a new routine. People with heart disease, diabetes, joint problems, or unexplained chest pain or shortness of breath should also talk to their doctor first.

Even without a formal exercise plan, small changes can help. “Walk faster for a few minutes, take the stairs quickly, or do a brief uphill walk,” Shen said. “Even just 15 to 20 minutes total spread across the week—a few minutes at a time—can provide meaningful health benefits.”