Question

which statement about warming up before physical activity is true?
a warm - up is a period of semistrenuous activity that prepares the body for physical activity.
a warm up should last about 15 to 20 minutes before being physically active.
stretching is important for flexibility and keeps muscles from tightening up during physical activity.
a warm - up increases the amount of oxygen to the brain by raising body temperature.

Explanation:

Warming - up involves light - to - moderate activity to prepare the body for physical exertion. Stretching during warm - up helps improve flexibility and prevent muscle tightness during exercise. A warm - up is not semistrenuous, usually lasts 5 - 10 minutes, and while it raises body temperature, it doesn't directly increase oxygen to the brain in the way stated.

Answer:

C. Stretching is important for flexibility and keeps muscles from tightening up during physical activity.