Try intervals to maximize the fitness benefit of walking

Don't have time for regular 60-minute walks? No problem. Research shows that shorter walks with periods of higher-intensity movement mixed in—an approach to exercise known as interval training—can garner even greater health benefits than longer, lighter-intensity ones.

Picking up the pace

Studies suggest that interval walking can support good health in several different ways. It may help to:

• Improve fitness
• Reduce body fat percentage
• Increase or maintain muscle and strength
• Improve heart and blood vessel health
• Lower the likelihood of developing diseases related to lifestyle, such as diabetes, heart disease, and obesity

And if you already have a chronic condition, interval training may help to manage symptoms.

Why a little burst of effort can mean a lot

It’s not known exactly why interval walking (and other kinds of interval training) may have more perks than longer, slower workouts. But there are a few theories.

During a workout, stimulating your muscles leads to a process that makes mitochondria work more effectively. Mitochondria are parts of human cells that are important for boosting metabolism, which is the way your body converts food into energy. Their action may also play a role in reducing your risk of high blood sugar and obesity.

Another possibility is that increased activity for short periods helps open the large blood vessels of the heart, reducing the risk of coronary artery disease. Researchers have also found that interval training can help lower your heart rate after training. A high heart rate—even without other risk factors—is a predictor of sickness and death from heart disease.

Higher-intensity exercise has been shown to be more effective than lower-intensity activity in improving body composition and reducing fat. It may work particularly well for fat around the abdomen, where buildup can be particularly dangerous.

Intervals 101

Doing interval training can be a little trickier to figure out than other exercise regimens (like getting 150 weekly minutes of moderate-intensity exercise at a steady pace). But there are several ways to make sure you are increasing your pace the right amount.

First, it helps to know your maximum heart rate. You can figure this out by subtracting your age from 220. That would be about 180 beats per minute for an average 40-year-old person, and 85 percent of that would be about 153 beats per minute.

A wearable fitness tracker can also help you determine your heart rate. If you don’t have one, you can count your pulse at your wrist for 30 seconds and double that number to get your beats per minute.

Once you know your maximum heart rate, shoot for a mix of high- and lower-intensity exercise.

• High-intensity exercise involves working at a pace that is 70 percent to 85 percent of your maximum heart rate. During this workout, you should only be able to say a few words without pausing to catch your breath.
• Lower-intensity exercise is 50 percent to 70 percent of your maximum heart rate. During this workout, you should be able to talk but not sing.

In much of the research on interval walking, participants walked a total of 30 minutes to an hour at least three times a week. Interval work can range from alternating between low- and high-intensity periods of one minute each to longer intervals of up to four minutes. The idea is that you push yourself during the intervals, then give our body (and breath) a chance to catch up while you walk during the slower periods.

A variety of interval workout plans can be found online, or you can talk to your healthcare provider or a personal trainer to determine a walking regimen to fit your needs, goals, and fitness level. Always speak to a healthcare provider before starting an interval program, especially if you have existing health conditions. Be extra cautious if you have diabetes, heart disease, or high blood pressure.