Write the next sentence in this paragraph:

How to burn more calories while walking
Take a hilly route.
One of the simplest ways to increase the intensity and total calorie burn of your walk is by walking over some hills. Work on finding a hilly route or using a treadmill and changing the incline to help you burn extra calories on your walk.

Choose your answer from: (1). Try choosing a treadmill with a glide. For example, if you tend to walk on the sidewalks, you could get a treadmill with an on glide unit. (2). Take a walking walk on the treadmill. A walking walk (or a regular walk if you choose to walk) can help your body burn extra calories and work your legs, helping you walk higher. (3). Try taking a 15 minute walk for 30 minutes or 45 minutes over the course of an hour or two. Try walking for one hour around a track, stationary bike or treadmill. (4). Walking hills is a great aerobic exercise. It burns significantly more calories than walking on a flat surface and also specifically helps strengthen the back of your legs and glutes.
(4).