Even if we’re not thrilled about it, most people have come to grips with the fact that exercise might just be the single most important thing we can do for our health and longevity. But some may still have the idea that if they haven’t been active their whole lives, then there’s little point in starting in middle age, let alone as a senior.

Wrong. Developing healthy lifestyle habits (and stopping the unhealthy ones) have a big impact on health no matter what age you are, or even if you have high blood pressure. In fact, when seniors with high blood pressure took up even moderate walking, it significantly reduced their risk of death, according to a new study.

So there really is no excuse not to take a walk.

This level of fitness is achievable by most elderly individuals engaging in a brisk walk of 20 to 40 minutes, most days of the week.

The researchers studied more than 2,100 men over the age of 70 who had high blood pressure. The men took fitness tests that measured metabolic equivalents — METs. A MET is how much oxygen the body uses per kilogram of body weight in one minute. The higher your “peak MET” value, the better shape you’re in.

“To put this in perspective, the peak MET level of a sedentary 50-year-old is about five to six METs,” said researcher Peter Kokkinos in a press release. “For a moderately fit individual, it's about seven to nine METS, and for a highly fit person, it's 10 to 12 METs. Still, marathon runners, cyclists and other long distance athletes often have MET levels of 20 or higher.”

The participants in the study were followed for nine years, and the number of deaths that occurred during this period were recorded.

And the pattern was clear — the higher the level of fitness, the lower the risk of death. “The death rate is cut in half for those in the highest fitness category,” said Kokkinos.

In fact, for each single MET increase, a person’s risk of death was lowered by 11%. “Although this does not sound like a big drop in the death rate,” said Kokkinos, a researcher at the Veterans Affairs Medical Center, Georgetown University School of Medicine, “the impact of it is revealed when we compared low-, moderate- and high-fit individuals to the least fit, who achieved less or equal to four MET.”

The breakdown went like this: Men in the low-fit category (4.1 to 6 peak METs) had an 18% reduced risk of death; those in the moderately-fit category (6.1 to 8 peak METs) had a 36% lower risk of death; and those in the high-fit category, with peak METs of over 8, had a 48% reduced risk of death.

Keep in mind that all of the participants had high blood pressure. That the death risk was reduced by exercise even in this group shows just how valuable it can be.

So what is moderate exercise for a senior?

“[A] level of fitness is achievable by most elderly individuals engaging in a brisk walk of 20 to 40 minutes, most days of the week,” said author Charles Faselis, an internal medicine doctor also at the Veterans Affairs Medical Center.

But even if you can’t exercise this much, activity seems to add up, so every little bit really does count. Always talk with your doctor before beginning any exercise routine, especially if you have high blood pressure. He or she can help you determine the best type of exercise to begin with, and help you design a long-term goal.

The study was published in Hypertension.