Regular exercise reduces the risk of many chronic health conditions, including obesity and heart disease. Some physical activity is better than none, but most health benefits occur with at least 150 minutes per week of moderate-intensity physical activity, such as brisk walking, or 175 minutes of vigorous intensity activity, including jogging or running. Walking or running can be performed outside or on a treadmill. For general health and weight loss purposes, treadmill training is just as advantageous as road training, and the treadmill provides added benefits, such as increased safety and convenience.
Benefits of Walking
Walking on a treadmill offers many of the health benefits of running, if performed at moderate intensity and for a sufficient length of time. Furthermore, moderate-intensity activities, including walking, are safer than vigorous intensity activities, such as running, and may increase likelihood of sticking to an exercise program in the long-term. For the most health benefits, you should walk at a speed that causes you to break into a light sweat and quicken your breathing. Walking on a treadmill at a moderate-intensity 3.5 mph for 30 minutes per day, or 2.5 hours per week, offers substantial health benefits, and walking for five hours per week provides even greater benefits.
Benefits of Running
Compared with walking, running on a treadmill burns more calories in less time. In general, one minute of vigorous aerobic activity is equal to two minutes of moderate activity. Running for an hour at a speed of 5 mph burns 584 calories in a 160 pound person, compared with the 277 calories burned by walking at 3.5 mph for an hour. Epidemiologic studies, including those reviewed in a 2005 meta-study published in "American Journal of Cardiology," show that vigorous-intensity aerobic exercise provides greater heart-protective benefits than moderate-intensity exercise.
Treadmill Workout Intensity
To determine whether your treadmill workout is difficult enough to provide substantial health benefits, you can measure the intensity of your walking or jogging routine by using the "talk test." If you can participate in a conversation but would have difficulty singing, you are probably working out at a moderate intensity. If you can't say more than a couple words without pausing for a breath, you are working out vigorously.
Effects on Weight Loss
Although running vs. walking burns more calories, some studies, including a trial published in "British Journal of Sports Medicine," and a study published in "Journal of the American Medical Association," indicate that moderate-intensity aerobics may provide equivalent weight loss benefits to vigorous-intensity exercise in overweight people. The "British Journal of Sports Medicine" trial evaluated the effects of moderate and vigorous exercise on fat oxidization in obese boys, finding that more vigorous exercise did not burn more fat. Researchers theorized that the muscles of obese people may have a more limited capacity to burn fat than those of lean people. The "JAMA" study, which examined the effects of moderate and vigorous exercise on overweight women, also found that vigorous and moderate activities provided equivalent weight loss benefits.
Benefits of Light Physical Activity
While moderate-intensity activities, including brisk treadmill walking, offer greater health benefits than light-intensity exercise, such as walking at a slower pace, there is evidence that even light exercise provides some health benefits. A 2010 study published in "International Journal of Epidemiology" found that even light-intensity exercise reduces risk of an early death, especially in previously sedentary people.