A 20-minute bike ride to work, as part of your daily exercise routine, gives your body a complete workout. As well as toning muscles in your legs, thighs and calves, you benefit from the cardiovascular activity and effectively burn calories.
The amount of calories you burn biking in 20 minutes depends on how much you weigh and how fast you cycle. A leisurely bike ride of 10 mph or less will burn fewer calories than cycling faster in a 20-minute period. A 150-lb. person biking at less than 10 mph will burn 90 calories in 20 minutes, according to the Calories Burned Biking website. By increasing the speed to 12 to 14 mph, that person will burn 198 calories in 20 minutes. A 200-lb. person will burn 120 calories with a leisurely bike ride, but traveling between 12 and 14 mph will burn 264 calories in 20 minutes. A 240-lb. person will burn 144 calories in 20 minutes, while more vigorous biking will burn 317 calories.
If your bike ride incorporates some hilly terrain, you'll have to work harder and burn more calories. Calories burned could also be affected by factors like pushing against a headwind, which causes greater resistance or by wearing a heavy backpack. By gradually increasing the speed of your cycling, you'll see greater weight loss over those 20 minutes.
Cycling for 20 minutes a day is beneficial, as the Department of Health and Human Services recommends at least 2 1/2 hours per week of moderate activity, such as leisurely bike riding, or 1 1/4 hours of vigorous aerobic exercise, such as biking between 14 and 16 mph. In addition, a strength-training exercise is recommended at least twice a week. For weight loss, you may need to increase your activity more, according to MayoClinic.com.