You’ve heard the recommendation: Federal health guidelines call for engaging in at least 150 minutes of “moderate-intensity” physical activity each week. But how can you tell if your exercise program meets that standard?
San Diego State University researcher Simon Marshall has come up with a practical rule of thumb for figuring out "moderate intensity" as it applies to walking: Take at least 100 steps per minute. That pace – amounting to brisk walking – is enough to raise your heart rate sufficiently to boost your heart.
Marshall’s prescription – detailed in a special health report from Harvard Medical School, “Exercise: A Program You can Live With” – is based on a study of 97 women and men. Each walked on a treadmill four times at four different speeds – from 2.4 miles per hour to 4.1 mph – while a machine measured the energy participants expended. The volunteers also wore pedometers to count their steps.
The researchers determined that walkers who took at least 100 steps per minute met the national standard for moderate-intensity exercise.
To calculate your steps per minute:
• Use a watch and an inexpensive pedometer – a device that records your steps – to track your walking pace.
• A heart monitor can also determine when your heart rate is between 50 percent and 85 percent of your maximum heart rate (220 minus your age) – a level that indicates you are engaging in moderate-intensity exercise
• Try what’s called the "talk test." You are exercising at moderate intensity if you are breathing faster than normal but can still say a sentence or two out loud. If you aren't out of breath, you are walking at low intensity; if you have trouble finishing a sentence, you are exercising at high intensity.