Please choose the correct ending to complete the given sentence: Sports and Fitness: [header] How to get the best workout on a treadmill [title] Determine your maximum heart rate before you begin your treadmill workout. [step] All you have to do is subtract your age from 220. So, if you are 40 years old, your maximum heart rate is 180.

Ending1: If you are over 40, your maximum heart rate is 80. Make sure to keep that in mind, however, before beginning your workout routine. Ending2: If you are 35, your maximum heart rate is 165. If you are older, your maximum heart rate is 120. Ending3: If you are 47, your heart rate is 250. So, if you are 74, your heart rate is 176. Ending4: [title] Run or walk on the treadmill until you reach at least 70 percent of your maximum heart rate. [step] The american college of sports medicine says that when you hit this target, you maximize the amount of fat and calories you burn.

Answer format: ending1/ending2/ending3/ending4