In the study, researchers looked at two groups of women — those with good exercise capacity and those with poor exercise capacity. Women with good exercise capacity were able to exercise at an intensity of 10 metabolic equivalents (METs) or better during a stress echocardiogram. MET level is a measure of how much energy is burned during an activity — it’s also a proxy for the intensity of a physical activity.

Anything over 6 METs is considered vigorous exercise. Running a 10-minute mile is about 10 METs. Mountain biking uphill is 14 METs. Researchers found that women with poor exercise capacity were almost four times more likely to die from cardiovascular disease compared to women with good exercise capacity.

Poor exercisers were also twice as likely to die from cancer and more than four times as likely to die from other causes, compared to women with a higher fitness level.

Most of the women in the study were between 50 and 75 years old. Researchers followed the women on average for about 5 years.

While the study found that having a higher exercise capacity is a good thing, the researchers didn’t look at what women did to reach that level of fitness.

Vigorous exercise simply challenges the body more so than moderate exercise, and the response therefore is greater so as to better prepare for that next vigorous challenge. The body responds to exercise in a way that prepares it for similar challenges in the future.

These responses include a greater flow of blood to the muscles — which carries oxygen and fuel — as well as increased muscle mass and strength.

Body fat is also reduced as fat is converted to fuel, and insulin signaling improves, which can reduce the risk of type 2 diabetes.

There’s also a boost to your exercise capacity.

Vigorous exercise — for example, high-intensity training — tends to be superior to lower intensity exercise for increasing maximal MET level. 

It also takes less time to get similar health benefits from vigorous exercise than from moderate-intensity activities.

However, this doesn’t mean vigorous exercise is the only way to go. 

Intensive is Exercise Safe for All Ages

Aging exercisers often have the potential for even greater benefits to health than their younger counterparts, mostly because they tend to be more de-conditioned. 

Researchers noted that vigorous exercise — along with strength training — can slow and sometimes reverse the decline in muscle mass that begins after age 30 and becomes more pronounced with age.

One of the most well-known is HIIT or high intensity interval training.

Few studies have compared HIIT to just continuous vigorous exercise — like biking up a mountain for half an hour.

He said many people find HIIT attractive for two reasons — the exercise sessions can be short and there’s a built-in low-intensity “recovery” period.

Some HIIT workouts, though, involve a lot of movement — think burpees and jumping jacks. This can be hard on the joints, especially if you are middle-aged or older, or have more weight.

Exercising Harder, but Safely

The risk of injury increases with greater amounts and intensities of activity beyond the guideline-recommended minimum level. But done appropriately, vigorous exercise can be safe.

People should check with a doctor before starting a vigorous exercise program. And listen to your body and stop if something doesn’t feel right.

Increasing the intensity of your workouts gradually is usually safer. It also helps you stick with it.

There is nothing to be gained by going ‘all out’ several times a week. In general, it is usually considered best to do a combination of exercise intensities; some lower and longer, with some higher and shorter.

But even if vigorous exercise is not your thing, don’t trade in regular movement for binge watching television.

The casual exerciser shouldn’t despair. There are great benefits to even a little bit of exercise, even if it doesn’t increase your fitness to a high degree.

Sit less, move more — every minute counts.

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