How many different styles of runs can you think of? Online running authority Competitor.com has put together a slide show explaining the differences in eight of the oldest, most popular runs. The types covered are Recovery, Base, Long, Progression, Fartlek, Hill Repeats, Tempo, and Intervals. It's suggested that runners try each style in order find the one that is most efficient for them. From there, runs can be combined, mixed, and matched.
Some of the concepts may be new to those who aren't hardcore runners. For instance, a Fartlek workout is one which mixes up intervals of varying duration and distance. A great training tool, an example of a Fartlek run would be to run six miles at a natural pace with ten one minute pickups.
To read up on the eight types of runs, as well as to potentially pick up some new ideas for your next trek, head over to Competitor.