I have found that three basic sessions hold the hierarchy: the long run, the transition run and the fartlek/speed run.
The Long Run
This session makes up the basic foundation of any Ironman/long-course run program, but its importance does not fall by the wayside as the race distance decreases. Long runs build stamina and durability and help you maintain good form under fatigue.
Preferably, long runs should take place over semisoft surfaces (such as dirt roads or well-packed trails) and should build in quality as your fitness improves. You should begin these runs feeling fairly comfortable and eventually make your way to an intensity level where conversation is possible.
The Transition Run
Most working athletes are time-limited, and getting in numerous sessions in the week can be a challenging task. With this in mind, strive to run off the bike on your key cycling workout days to help increase run frequency while developing the skill of running off the bike with ease.
A baseline transition run duration of 15 minutes. It is simple, easy and highly effective when done consistently over time. If time permits, an athlete can extend these sessions to help with race pacing and execution. However, as little as 15 minutes done repeatedly through the week helps athletes achieve high run frequency even if the overall run volume is moderate.
The Fartlek/Speed Run
This refers to runs that are often classified as higher intensity. I put this one last because I do believe that this should be done to complement the overall run program as opposed to being considered the most important.
Begin with sessions that are built around time/duration and not on a fixed distance or pace. As fitness improves, workouts can be formalized with distance repeats at a set pace. Forcing high paces too early can often put you at risk for injury with little additional upside in fitness. The key is to train with the fitness that you have, and not the fitness that you want.
Happy Training 🙂