Please choose the correct ending to complete the given sentence: Sports and Fitness: [header] How to improve your 5 k race time [title] Engage in hill training. [step] Hill training is a form of training where you run up and down hill. This can help build endurance and muscle, resulting in faster speeds.

Ending1: [title] Use your 10 k training sessions to improve endurance. [step] Mountain cycling is a variation of hill training that uses the long distance bike. Ending2: Also, you may encounter a hill during a 5k, so hill training can help you prepare. [substeps] Find a steep hill in a safe area near you. Ending3: Additionally, it helps you identify which road to use more easily. [substeps] Contrary to popular belief, hill classes increase the quality of your fitness. Ending4: Hill training will also give you the flexibility to engage in high-altitude races. [title] Aim for a healthy weight loss diet.

Answer format: ending1/ending2/ending3/ending4