Repeats - the distance of the repeating running segment does not change (ex: four 440 yard repeats with a 220 yard recovery jog in between each)Pyramids - the distance of the repeating running segments peaks and then returns to the beginning distance (ex: repeats of 220 yards, 440 yards, and up to 1 mile before returning to 440 yards and then 220 yards)Ladders - the distance of the repeating running segments either steadily increases or decreases (ex: 220 yards, 440, 880, up to 1760 yards or run in the reverse order of 1760 yards down to 220 yards)