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.
The same man would burn 151 calories running a mile at a pace of 6 miles per hour (total exercise duration = 10 minutes). And if you were strolling for a mile at a pace of 2 miles per hour, you would burn 113 calories but it would take you twice as long (total exercise duration = 30 minutes).