Some people prefer interval training because
a. the intensity of the exercise doesn't increase, only the time does. b. they can exercise at a steady, but slow, pace for longer periods of time. c. it's performed with speed and may not cause boredom. d. they've found that this type of training is best for beginners

Life expectancy in the united states is (76.4 for men and 81.1 for women). life expectancy is not the same as healthy life expectancy. healthy life expectancy is the number of years a person is expected to live in this number is obtained by subtracting years spent in poor health from overall life expectancy. the world health organization (who) calculates healthy life expectancy in 194 countries. the united states ranks twenty-ninth in the world using this measurement, with an average of of healthy life expectancy. singapore ranks number one (76 years), and japan is number two (75 years).