What does 'don't hold your breath' mean?

Read the rough-draft paragraph. exercising daily is one of the best ways to the body fight fatigue, illness, stress, and weight gain. whether taking a bike ride, enjoying a walk, or going for a swim, the type of activity is not as important as exercising consistently. often, people begin the new year with the resolution of exercising, but within a few months that commitment is quickly forgotten. the key is to choose something that is accessible, enjoyable, and affordable. exercising just thirty minutes a day not only strengthens the heart and lungs, but it also to boost one’s energy. another way to feel more energized is to eat a balanced diet. since no single food item can supply the body with everything it needs, it is important to eat a variety of foods. so to maintain a long, happy life, get out there and get moving, and enjoy a wide range of healthy meals. which statement best describes the mistake the writer makes in this paragraph?