It is recommended by the center for disease control (cdc) to exercise 1 time per week for 3 hours. question 11 options: a) true b) false question 12 (2.5 points) question 12 unsaved when starting an exercise program, you should begin as hard and as fast as you can in order to quickly get your body used to the exercise. question 12 options: a) true b) false question 13 (2.5 points) question 13 unsaved your heart is a muscle that becomes more efficient with exercise. question 13 options: a) true b) false question 14 (2.5 points) question 14 unsaved it can be dangerous to over-exercise. question 14 options: a) true b) false question 15 (2.5 points) question 15 unsaved when we exercise, we should try to get our heart rates into the: question 15 options: a) danger zone (dz) b) target heart rate zone (thr) c) the upside down (tud) question 16 (2.5 points) question 16 unsaved if you are feeling lightheaded or dizzy it means you are working in your target heart rate zone and should just keep going. question 16 options: a) true b) false