Please choose the correct ending to complete the given sentence: Sports and Fitness: [header] How to run longer without getting tired [title] Train within your limits. [step] Whether you are only beginning to run or have already made a practice of it, design a training schedule based on your current abilities. Forget " no pain, no gain.

Ending1: " plan out your training hours and schedule it in an all-out run over the course of several weeks. For example, consider having three days a week run over and five days a week running outside of the road. Ending2: " here are some things to notice : [substeps] Walk for 30 minutes then slowly increase the duration of your running every two hours until your stamina has doubled. Your running range should be at least around 30 to 60 miles (8 to 25 km) and you need maximum endurance. Ending3: " resist the urge to push yourself too hard too fast. Keep your runs sensible and achievable, especially in the beginning. Ending4: " instead, set aside some time for cardio exercises, which increase stamina, speed, and endurance. Start with a short run at the beginning of your week and increase the intervals as you get more used to running.

Answer format: ending1/ending2/ending3/ending4