Definition of organism for English Language Learners. : 1  an individual living thing. : 2  a system with many parts that depend on each other and work together.
Figuring out how many calories you burn when running is, on a simple level, a fairly straightforward calculation. Most experts (and lots of studies) suggest that a person of average weight burns about 100 calories in a mile of running.
You know that walking burns calories, but just how many calories does it burn? In general, a 150-pound person walking at average speed (from two to three-and-a-half miles per hour) can count on burning about 80 calories a mile. (This amount increases with your weight, your speed, and the shortness of your legs.