Race Planner

It counts the full weeks from today to race day, then takes the longest standard plan that fits and suits the distance. Longer is better up to a point: beyond the maximum below, extra weeks add fatigue rather than fitness, so the plan starts later and you run easy until then. Below the minimum, there is not enough time to build safely, and the planner offers the earliest race date that works instead.

From VDOT, the fitness score in Jack Daniels' running tables. Your goal time (or recent race) gives a VDOT through the Daniels and Gilbert equations, and each run type is set at a share of it: easy running at 62 to 74%, threshold at about 88% and intervals at about 97.5%. For the example 1:55:00 half marathon:

The full method and its sources are on the methodology page. VDOT is an estimate from a race result, not a lab test, so treat the paces as a starting point and adjust to how the runs feel.

It cuts volume in the last 2 weeks so you start the race rested, while keeping some faster running so your legs stay sharp. Marathon plans of 16 weeks or more taper for 3 weeks; other marathon plans and every half marathon plan taper for 2; 5K and 10K plans use race week alone. In the example, the long run peaks at 19 km in week 14, drops to 13 km in week 15, and race week totals 35 km including the race, against a peak week of 46.5 km.

Fitness is built in the recovery after hard weeks, not during them. Every fourth week before the peak drops the long run to about 80% and trims the easy runs, so the body absorbs the work before the next block. In the example, weeks 4, 8 and 12 are cutbacks; they are hatched in the plan table so you can see them coming.

From two published position statements of the American College of Sports Medicine. Thomas, Erdman and Burke (2016) give 30 to 60 g of carbohydrate an hour for efforts of 1 to 2.5 hours and up to 90 g beyond that; Sawka and colleagues (2007) give about 400 to 800 ml of fluid an hour, adjusted to sweat rate. The planner suggests a first gel at 45 minutes and one every 40 minutes after that, and none for races under 75 minutes. It is general guidance, not medical advice: rehearse it on long runs first.