Please choose the correct ending to complete the given sentence: Health: [header] How to do a butterfly stretch [title] Exercise. [step] The butterfly stretch is useful as a cooling down stretch. Before doing it, you will want to have done at least five to ten minutes of light to moderate cardio activity, such as walking or cycling.

Ending1: [substeps] [substeps] Get on all fours with your knees bent and arms straight. Keep your knees in or out of alignment with your body. Ending2: Good cardio activities include jogging, swimming, and ballet. [substeps] If you don't feel like you can do high intensity exercises, yoga, or light weight exercises will likely provide no such benefits. Ending3: Stretches like this before you are warmed up can result in an injury. [title] Sit on the floor with both legs straight out in front of you. Ending4: Doing this will also help strengthen and firm your abdominal muscles, which can make your workout easier. [substeps] Cycling is an exercise that helps stretch your core, shoulders, and back, while also encouraging your muscles to contract.

Answer format: ending1/ending2/ending3/ending4