People who walk for exercise should aim for a pace of 100 steps per minute to ensure their workout is intense enough, according to researchers.

Many people who want to keep fit use a pedometer to keep track of how many steps they take. However, the device gives no information on how intensely they're exercising — that is, whether their heart rate is being raised enough to improve physical fitness.

In the new study, researchers found that the average walker should aim for 100 steps per minute at a minimum in order to get a moderate-intensity workout.

Experts recommend that adults get at least 30 minutes of moderate activity, five times per week. If those 30 minutes are achieved in one session, that means taking a minimum of 3,000 steps per session. However, the researchers point out in the American Journal of Preventive Medicine, walkers can also break those steps down into several shorter exercise sessions throughout the day.

"Because health benefits can be achieved with bouts of exercise lasting at least 10 minutes, a useful starting point is to try and accumulate 1,000 steps in 10 minutes, before building up to 3,000 steps in 30 minutes," lead researcher Dr. Simon J. Marshall, of San Diego State University, said in a news release from the journal.

A simple pedometer and a wristwatch, he added, offer walkers a way to ensure they are working out intensely enough.

The findings are based on exercise tests given to 97 healthy adults with an average age of 32. In general, men needed to walk at a pace of 92 to 102 steps per minute to achieve a moderately intense workout for their hearts. The range for women was between 91 and 115 steps per minute.

"We believe that these data support a general recommendation of walking at more than 100 steps per minute on level terrain to meet the minimum of the moderate-intensity guideline," Marshall said.