Polar bears are in danger of extinction in the future if globalwarming continues, as their habitat, Arctic sea ice, is shrinkingevery year, making it difficult for bears to have enough food tolast through the lengthening summers.With a population of nearly 25,000, the polar bear is not in dangerof extinction now.
1 In general, anything that is good for your heart is great for your brain. 2  Aerobic exercise is great for body and brain: not only does it improve brain function, but it also acts as a first aid kit on damaged brain cells.
Aerobic exercise is any physical activity that makes you sweat, causes you to breathe harder, and gets your heart beating faster than at rest. It strengthens your heart and lungs and trains your cardiovascular system to manage and deliver oxygen more quickly and efficiently throughout your body.