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.
In general, running burns more calories per minute than cycling, Dr. Tanaka said, although the differential slims if you cycle vigorously. According to broad calculations from the American College of Sports Medicine, someone weighing 150 pounds who runs at a brisk seven minutes per mile will incinerate about 1,000 calories per hour.