Please choose the correct ending to complete the given sentence: Work World: [header] How to become a calvin klein model [title] Do cardio 4-5 days per week to stay lean. [step] A gym membership will be your best friend if you plan on having a future as a professional model. Begin performing cardiovascular exercise like running, swimming, cycling, or aerobics in order to stay trim and healthy.

Ending1: [title] Buy fitness products at your local gym or pharmacy to prevent cramps in your joints. [step] Instead of buying a gym bag, try calling gyms and giving them your personal e-mail. Ending2: Playing sports is no different from going to a basketball game. [substeps] Make sure your workout areas are adequately covered in gym attire, including warm-up mats, sun screens, and treadmills, which can help even out your silhouette. Ending3: Your goal should be to get your heart rate up, break a sweat, and maintain a steady pace for 30 minutes to an hour at a time. [substeps] To continue seeing progress and maintain your figure, you'll need to find time to fit regular exercise into your busy schedule. Ending4: Avoid any membership after you've completed your first year. [substeps] You will be able to prevent muscle cramps and weight gain in the future by exercising for 3-4 days per week to keep lean muscle at bay and to work hard for 5 days a week.

Answer format: ending1/ending2/ending3/ending4