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.
How to Achieve an Aerobic Effect. The word aerobic is defined as with oxygen and references the use of oxygen by the body during a period of activity. The intent of regularly performing an aerobic exercise is to increase your heart rate to your target heart rate and maintain that level for a minimum of 20 consecutive minutes. By doing so, you will achieve what is defined as an aerobic effect.