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.
Aerobic exercise stimulates the growth of new neurons, also known as neurogenesis through the release of brain-derived neurotopic factors. Endurance exercises release Irisin, a hormone linked to improved cognitive function, fat loss and overall health.
In contrast, aerobic exercise includes lower intensity activities performed for longer periods of time. Activities such as walking, long slow runs, rowing, and cycling require a great deal of oxygen to generate the energy needed for prolonged exercise (i.e., aerobic energy expenditure).In sports which require repeated short bursts of exercise however, the anaerobic system enables muscles to recover for the next burst.ctivities such as walking, long slow runs, rowing, and cycling require a great deal of oxygen to generate the energy needed for prolonged exercise (i.e., aerobic energy expenditure). In sports which require repeated short bursts of exercise however, the anaerobic system enables muscles to recover for the next burst.