Question: Painkilling chemicals that occur naturally in the body are known as A. hormones. B. triglycerides. C. endorphins. D. platelets. Answer: The correct answer is C. endorphin's. Question: Specificity is important to a fitness program because it A. makes the workout more enjoyable. B. allows you to choose the right types of activities to improve a particular fitness element. C. increases the demands you place on your body. D. helps you to exercise beyond your regular daily abilities. Answer: Correct answer is B. allows you to choose the right types of activities to improve a particular fitness element. Question: Olympic athletes have lower resting heart rates because A. their lungs tend to be naturally larger. B. they have a lot of muscle mass due to weightlifting. C. they exercise regularly, which improves the efficiency of their heart. D. they tend to eat low-fat diets. Question: Correct answer is C. they exercise regularly, which improves the efficiency of their heart. Question: What does a measure of your cardio-respiratory endurance tell a fitness professional? A. Your anaerobic fitness, or how well your leg and arm muscles work B. How long you can sustain a weightlifting program C. What type of exercises you've been doing D. Your aerobic fitness, or how efficiently your heart is working Answer: Correct answer is D. Your aerobic fitness, or how efficiently your heart is working. Question: Which type of fat may help lower the risk of heart disease? A. Saturated fat B. Trans fat C. Unsaturated fat D. Cholesterol Answer: Correct answer is C. Unsaturated fat.