Final answer:
Sedentary lifestyles contribute to poor health by involving little activity, resulting in weakened muscles and an inefficient cardiovascular system, leading to various health issues such as weight gain and heart disease.
Step-by-step explanation:
Sedentary lifestyles contribute to poor health because they involve little activity. When a person engages in little physical activity, their muscles become weak and their cardiovascular system becomes less efficient. This can lead to weight gain, heart disease, diabetes, and other health problems. Regular physical activity, on the other hand, can improve circulation, strengthen muscles, and boost overall health and well-being.
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