Short bursts of vigorous activity—like climbing stairs or very fast walking—may cut the risk of cancer.

Scientists measured vigorous activity using a wrist accelerometer in 22,398 people who reported no leisure-time exercise on questionnaires.

Over the next 6½ years, those whose accelerometers registered an average of 4½ minutes a day of vigorous activity—each bout lasting a minute or less—had a 20 percent lower risk of cancer than those whose accelerometers registered none. Their risk of breast, colorectal, or uterine cancer (which have stronger links to exercise) was 31 percent lower.

What to do

No time to exercise? Try walking up stairs, uphill, or as fast as possible, or carrying groceries or children for a minute or two. This kind of study can’t prove that vigorous exercise bouts can prevent cancer, but it’s a small price to pay for a big potential payoff.