Quick Answer. In an officially-sanctioned MLB baseball game, there are 9 innings. If the home team is ahead in the top of the ninth and earns 3 outs, the game ends at 8 1/2 innings. If the game is tied after the away team earns 3 outs in the bottom of the ninth, the game goes into extra innings. Keep Learning.
When you exercise, the muscles you use require more energy. When exercise can be sustained, this demand is met primarily by aerobic means. Aerobic energy production in muscles results in increased gas exchange at the lungs, because more oxygen is taken in and more carbon dioxide is released.
Take your pulse to determine your heart rate during a workout. Photo Credit Jupiterimages/Photos.com/Getty Images. Aerobic exercise causes your heart to beat faster and your muscles to exert themselves, promoting calorie burn. While higher-intensity physical activity burns calories faster, it can be difficult to know how hard to push your body. Your heart rate is a useful measurement that helps you determine your aerobic exercise intensity, and maximize fat burn.