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.
When you're doing aerobic activity, such as walking or biking, exercise intensity correlates with how hard the activity feels to you. Exercise intensity is also shown in your breathing and heart rate, whether you're sweating, and how tired your muscles feel. There are two basic ways to measure exercise intensity: 1  How you feel. Exercise intensity is a subjective measure of how hard physical activity feels to you while you're doing it â your perceived exertion. 2  Your heart rate. Your heart rate offers a more objective look at exercise intensity.