Study: Walking could lower your risk of type 2 diabetes, and your speed may affect how much
When it comes to walking and type 2 diabetes risk, it's not just how much you do it that helps — it's also how fast you move, a new study has found.
Brisk walking is associated with a nearly 40% lower risk of developing type 2 diabetes later in life, according to the study published Tuesday in the British Journal of Sports Medicine.
"Previous studies have indicated that frequent walking was associated with a lower risk of developing type 2 diabetes in the general population, in a way that those with more time spent walking per day were at a lower risk," said the study's lead author Dr. Ahmad Jayedi, a research assistant at the Social Determinants of Health Research Center at the Semnan University of Medical Sciences in Iran.
But prior findings haven't offered much guidance on the optimal habitual walking speed needed to lower diabetes risk, and comprehensive reviews of the evidence are lacking, the authors said.
The study authors reviewed 10 previous studies conducted between 1999 and 2022, which assessed links between walking speed — measured by objective timed tests or subjective reports from participants — and the development of type 2 diabetes among adults from the United States, the United Kingdom and Japan.
After a follow-up period of eight years on average, compared with easy or casual walking those who walked an average or normal pace had a 15% lower risk of developing type 2 diabetes, the researchers found. Walking at a "fairly brisk" pace meant a 24% lower risk than those who easily or casually walked. And "brisk/striding walking had the biggest benefit: a 39% reduction in risk.
Easy or casual walking was defined as less than 2 miles (3.2 kilometers) per hour. Average or normal pace was defined as 2 to 3 miles (3.2 to 4.8 kilometers) per hour. A "fairly brisk" pace was 3 to 4 miles (4.8 to 6.4 kilometers) per hour. And "brisk/striding walking" was more than 4 (6.4 kilometers) per hour. Each kilometer increase in walking speed above brisk was associated with a 9% lower risk of developing the disease.
That faster walking may be more beneficial isn't surprising, but the researchers' "ability to quantify the speed of walking and incorporate that into their analysis is interesting," said Dr. Robert Gabbay, chief scientific and medical officer for the American Diabetes Association, via email. Gabbay wasn't involved in the study.
The study also affirms the idea that "intensity is important for diabetes prevention," said Dr. Carmen Cuthbertson, an assistant professor of health education and promotion at East Carolina University who wasn't involved in the study, via email. "Engaging in any amount of physical activity can have health benefits, but it does appear that for diabetes prevention, it is important to engage in some higher intensity activities, such as a brisk walk, to gain the greatest benefit."
Understanding the benefits of brisk walking
The study doesn't prove cause-and-effect, Gabbay said, but "one can imagine that more vigorous exercise could result in being more physically fit, reducing body weight and therefore insulin resistance and lowering the risk of diabetes."
Dr. Michio Shimabukuro, a professor and chairman of the department of diabetes, endocrinology and metabolism at the Fukushima Medical University School of Medicine, agreed — adding that "increased exercise intensity due to faster walking speeds can result in a greater stimulus for physiological functions and better health status." Shimabukuro wasn't involved in the study.
Walking speed may also simply reflect health status, meaning healthier people are likely to walk faster, said Dr. Borja del Pozo Cruz, principal investigator of health at the University of Cadiz in Spain, who wasn't involved in the research.
"There is a high risk of reverse causality, (wherein) health deficits are more likely to explain the observed results," del Pozo Cruz added. "We need randomized controlled trials to confirm — or otherwise — the observed results."
Lowering your diabetes risk
The overall message "is that walking is an important way to improve your health," Gabbay said. "It may be true that walking faster is even better. But given the fact that most Americans do not get sufficient walking in the first place, it is most important to encourage people to walk more as they're able to."
If you want to challenge yourself, however, using a fitness tracker — via a watch, pedometer or smartphone app — can help you objectively measure and maintain your walking pace, experts said.
If you can't get a fitness tracker, an easy alternative for tracking exercise intensity is the US Centers for Disease Control and Prevention's "talk test," which relies on understanding how physical activity affects heart rate and breathing. If, while walking, you're able to talk with a labored voice but not sing, your pace is probably brisk.