Running Training Plan Generator

Race distance and experience set the plan length. A beginner aiming at a 5K gets 8 weeks; an advanced runner targeting a marathon gets 16. Half marathons sit at 12 to 16 weeks, 10Ks at 8 to 12, marathons at 16 to 20. The numbers are pulled from training frameworks used by Hal Higdon, Jack Daniels, and Runner's World, then adapted for the level you select.

Each plan has four phases: base (about 30% of the weeks), build (40%), peak (15%), and taper (15%, minimum 2 weeks). The base ramps weekly mileage from roughly 50% to 70% of peak. Build ramps from 70% to 90%. Peak holds at 100% for one or two weeks. Taper drops back to 40% of peak in the final 2-3 weeks so you reach race day rested. Every fourth week is a cutback at 75% volume to let your body absorb the load.

About 80% of the running in a well-structured plan is at easy, conversational pace. You should be able to chat in full sentences while running. The remaining 20% is the hard stuff - tempo runs at lactate threshold, intervals at VO2 max effort, the long run that builds endurance. This 80/20 split is one of the most replicated findings in endurance training research and applies whether you're aiming at 25 minutes for 5K or sub-3 for the marathon.

Beginners often run their easy days too hard and their hard days too soft, ending up in the grey zone where everything feels moderately rough and nothing improves. If your easy run feels like work, slow down, even if the pace feels embarrassingly slow. Walk breaks during easy runs are fine. The marathon plan at peak still includes 4 easy runs for every interval session.

Honest niggle test: would the pain stop you walking? If yes, rest. Mild stiffness that loosens after 10 minutes of jogging is usually fine to continue. Sharp pain that worsens with each step, especially in the shins, knees, or Achilles, is a sign to stop and walk home. Missing one easy run costs almost nothing in fitness terms; missing six weeks because you ignored an early warning costs the whole race.

Sleep loss, illness, and high life stress all tank your ability to absorb training. The plan can flex: replace a tempo with an easy run, swap a long run to next week, or do the cross-training session twice. If you're missing more than one quality session a week, drop back to the previous level rather than push through and risk injury. The [Miles to Steps](/miles-to-steps) tool is useful if you're tracking volume on a watch that defaults to imperial.