The thinking has also changed somewhat on whether there’s a threshold minimum workout duration required to reap cardiovascular health benefits from aerobic activity. HHS’s new physical activity guidelines eliminated the long-standing recommendation that exercise had to last at least 10 minutes to count toward your daily total. (4) The new guidelines emphasize that small bouts of activity throughout the day can add up to big health benefits.
Relax your shoulders and bend your elbows. Bring your arms up to a 90-degree angle, but no more. Straight arms can lead to swelling or numbness of the fingers. Swing your arms naturally with each step, and should be bent at the elbow at a 90? angle. Your elbows should be close to the torso, with the hands going no higher than the center of the chest on the forward swing, or past the back of the hip on the back swing. Faster arms will make faster feet.
You know how sometimes it takes a glass of wine or a square (or three) of dark chocolate to blunt the edge of a rough day? Well, going for a walk is a zero-calorie strategy with the same benefits, says Dr. Jampolis. "Research shows that regular walking actually modifies your nervous system so much that you'll experience a decrease in anger and hostility," she says. What's more, when you make your walks social—you stride with, say, your partner, a neighbor, or a good friend—that interaction helps you feel connected, says Dr. Jampolis, which boosts mood. Finally, walking outdoors exposes you to natural sunlight, which can help stave off Seasonal Affective Disorder (SAD)—making it a potential antidote for the winter blues, says Dr. Jampolis.
Now see the effects of taking your walking speed up to brisk walking paces of 4 mph or more. You will burn more calories per mile as you increase your speed, but the biggest factor will still be how much you weigh. One benefit of walking faster is that you can walk farther in the same amount of time. If you walk for a set amount of time, that will mean burning more calories during an exercise session.
Walking programs have generally been studied for effectiveness. The Ottawa Panel recently concluded that aerobic walking combined with stretching and strengthening exercises, education, or behavioral programs is recommended to improve pain relief, functional status, and the quality of life of adult individuals with OA.32 Cycling is another form of aerobic exercise that can be beneficial. Low-intensity cycling was shown to be as effective as high-intensity cycling in improving function and gait, decreasing pain, and increasing aerobic capacity in subjects with knee OA.36 Cycling should be considered for those with arthritis who may have difficulty with a walking program because of joint pain.

Fitness trackers and fitness equipment can tally your calories burned while exercising, but they’re not always accurate. “Using a variety of sources and taking a ‘midpoint’ might help keep you honest,” says Hilaton. “I think it is important to keep in mind that all of these estimates of calories burned are just that: estimates. There are a lot of variables that go into the actual number of calories burned by any given individual in any exercise beyond speed and duration.” For a starting point, calculate your numbers with our Calories Burned Running Calculator.

Many people aim for a daily goal of 10,000 steps (or about 5 miles)—and an industry of fitness tracking devices has emerged to support them—but that magic number didn’t originate from scientific research, says John Schuna Jr., Ph.D., assistant professor of kinesiology at Oregon State College of Public Health. “It was first used in a Japanese marketing effort associated with one of the first commercial pedometers.” The device was called “manpo-kei,” which literally means "10,000 steps meter" in Japanese. 
On the other hand, some people like to know with more precision how their body is doing during exercise. If that's the case for you, then taking your heart rate during exercise and using a target heart rate training zone might be just the ticket. Target heart rate zones range anywhere from 50% to 100% of your maximum heart rate (your maximum heart rate is based on your age). Aerobic exercise is anything less than 85%, and anaerobic exercise is anything above that. A nice starting point for a sedentary individual is somewhere in the range from 50% to 65% (you can always increase as you get more fit) and 65% to 85% for more conditioned individuals. 

If you currently praise coffee for keeping your digestive system going strong, get ready to start thanking your morning walk instead. That's because a regular walking routine can greatly improve gastric mobility, says Tara Alaichamy, DPT, a physical therapist at Cancer Treatment Centers of America. "One of the very first things an abdominal surgery patient is required to do is to walk because it utilizes core and abdominal muscles, encouraging movement in our GI system," she says. (Check out these 7 things your poop says about your health.)