How this guide works

Every chapter shares one race. You pick the distance and date, then each step (where your fitness stands, a realistic goal time, a periodized training plan, your race-day pacing and your fuel) writes a line on a running race plan you can copy as a link. Nothing is stored and no account is needed.

How long do I need to train for a race?

A common guideline is around 8 to 12 weeks for a 5K or 10K from a reasonable base, 12 to 16 weeks for a half marathon, and 16 to 20 weeks for a marathon. The guide sets the length from your race date and builds the plan backward, with a base, build and peak phase and a taper before race day.

What time should I aim for?

A realistic goal comes from a recent result, not a wish. The guide uses the Riegel formula to scale a recent race or time trial to your race distance, which is the standard way to predict times across distances. Marathon predictions assume you put in the long-run endurance work, so treat them as a ceiling to train toward.

How much should I increase my mileage each week?

A widely used rule of thumb is roughly 10 percent a week, with a cutback every third or fourth week so your body absorbs the work. Most of your running should be easy, with about one harder quality session a week once you are into the build phase. The guide applies this 80/20 split and caps the long run at around a third of weekly volume.

Should I run even or negative splits?

For most runners, a negative split, starting a touch conservative and finishing faster, produces a better time and a better last few miles than going out hard. The pacing chapter turns your goal time into the exact per-kilometer or per-mile splits to run for an even, negative or positive strategy.

Do I need to take gels during a race?

For efforts under about 75 minutes, water is usually enough. Beyond that, taking on carbohydrate matters: common guidance is 30 to 60 grams an hour, and up to about 90 grams for trained runners using multiple carbohydrate sources. Always practice your fueling on long runs rather than trying something new on race day.

Figures are estimates for guidance only. Predictions use the Riegel formula; age grading uses World Masters Athletics / USATF road tables; population percentiles are anchored on published average times (RunRepeat, parkrun) with modeled spreads; training and fueling guidance follow standard periodization and ACSM / ISSN ranges. This is general information, not coaching or medical advice.