Cardiovascular Endurance by Dr. Brad Elliott Endurance means different things to different athletes. Even among expert's definitions vary greatly. The average triathlete or fly fisherman has this one memorized. Dorland's Medical Dictionary, on the other hand, doesn't list the word endurance. For the sake of this story, we will consider cardiovascular endurance to imply a level of aerobic fitness, which one pursues by sustained activity.
Aerobic activity means the body requires oxygen to generate energy in the mitochondria of the cell.
Interesting to know for those hammering out speed workouts. Ivan Steber, an amputee triathlete from Upland, CA, registered an impressive overall time of 12 hours and 36 minutes at the Ironman USA Lake Placid on July 30th. For simplicity, let's say that aerobic activity will depend more on fat for energy production. One last physiology peril, the body not only has different muscle groups for different actions, but different fiber types exist within a given group. Gluconeogenesis is the term used to describe this action.