Half Marathon Workshop: How to Choose the Right Plan

When someone writes to me asking for "the best half marathon plan," the first question I ask isn't about their goal time. It's about their week: how many days they can run without stealing hours from sleep, how many times they've run more than 10 miles in the last three months, and what happened the last time they ramped up volume too fast. Most plans circulating online don't fail because they're poorly designed on paper — they fail because people choose them based on a goal time rather than the actual capacity of the body that has to execute them.

The half marathon has a particular quirk that makes it deceptive: it's short enough to tempt you into training it like a prolonged speed race, but long enough to punish hard any mistake in volume dosing. Let's take this apart using what the evidence says and what I see on the track and on the road.

Volume matters more than intensity — up to a point

A study of more than 1,600 recreational runners preparing for a half marathon or marathon found that total training volume and the distance of the longest long run were directly related to race performance [PMID:32421886]. But the same study showed something many people ignore: injury risk also rises with volume, especially when the increase is abrupt relative to the runner's prior base.

This means choosing a plan isn't about choosing "how much volume I want" but "how much volume I can actually sustain without breaking down." If your current plan (or the one you're about to copy from an app) asks you to jump from 20 to 34 miles a week in four weeks, it doesn't matter how well-designed the intervals are — physiology doesn't negotiate with the arithmetic of a spreadsheet.

What this means in practice: before you look at the plan, look at your last 12 weeks of training history. If your average long run sits around 7-8 miles, a plan that asks for 11 miles by week 2 isn't "ambitious" — it's a recipe for a mid-cycle overuse injury.

Not every body responds the same way to the same stimulus

This is where the conversation gets interesting, and where a lot of generic plans fall short. A recent analysis of exercise biomarkers highlights how individual response to training — inflammation, muscle recovery, cardiovascular adaptation — varies significantly between athletes with similar training profiles [PMID:41922043]. Two runners can follow the exact same 12-week plan and end up with completely different levels of accumulated fatigue.

That's not an excuse to ignore structure — it's an argument for leaving room in the plan to adjust based on how the real body responds, not the theoretical body the plan was written for. A rigid plan that doesn't let you modify a loading week when sleep has fallen apart or work stress has spiked is optimized for an athlete who doesn't exist.

There's also a cardiovascular dimension worth mentioning, especially if you train for several half marathons a year or have been doing this for years. Research on the cardiac effects of prolonged endurance exercise in younger and older athletes shows that the heart adapts differently depending on age and years of exposure to endurance training [PMID:40667749]. This reinforces something I repeat often to my masters athletes: the plan that worked for you at 30 isn't automatically the right plan at 48. Your capacity to absorb load changes, and choosing a plan "because it worked before" ignores that physiological evolution.

The half marathon runner's profile has changed

A narrative review on participation and performance characteristics in the half marathon documents how the average runner's profile at this distance has evolved over the past two decades: more recreational participation, greater age diversity, and a performance gap between men and women that has narrowed in certain segments [PMID:36326961]. This matters because many "classic" plans were designed with a competitive club runner in mind, not the real profile that shows up at the start line of most half marathons today.

If your plan assumes you already have years of aerobic base, high prior mileage, or experience with threshold work — and you're a beginner or coming back after a long break — that mismatch between the plan and your starting point is one of the most common causes of frustration and injury mid-season.

Pacing: the plan doesn't end at training, it ends at the race

Choosing the right plan also means choosing how you're going to run on race day, because the training you did needs to align with the pacing strategy you're going to execute. A study on pacing in women and men in half marathons and marathons found consistent differences in how each group distributes effort: men tend toward more aggressive starts with steeper pace drop-offs in the second half, while women show, on average, a more even effort distribution [PMID:30646638].

This has a direct application: if your training plan doesn't include race-pace rehearsals in the final 30-40 minutes of the long run, you're leaving out one of the most decisive skills for the final result. It's not just about having the aerobic base — it's about knowing how to execute it without falling apart in the last 3 miles.

How to choose your plan: a practical framework

Instead of searching for "the best half marathon plan," I'd suggest evaluating any candidate plan with these five questions:

1. Does it respect my current base volume? The plan shouldn't ask for more than 10-15% above your average of the last 4 weeks in week 1.
2. Does it include a gradual progression of the long run? Look for moderate weekly increases with down weeks every 3-4 weeks, not a straight ascending line.
3. Does it have flexibility to adjust load based on recovery? If the plan is a fixed table with no room for judgment calls, you'll end up either forcing it or surgically abandoning it when real life interferes.
4. Does it include specific race-pace work, not just volume and pure speed? You need to practice holding your goal pace under accumulated fatigue, not just running it fresh.
5. Is it calibrated for your age and training history, not for a generic 28-year-old with a club base?

If a plan answers well to these five questions, it's probably a good candidate — regardless of whether you downloaded it for free, paid for it, or a coach built it for you.

My perspective from the track

Competing in masters 3000m, I understand well the temptation to copy the plan of someone who ran fast, assuming that volume or interval structure is the formula. But a coach's job — and the reason I push this so hard with my PMPRunning athletes — is to translate general evidence into the specific physiology of each person: their age, their injury history, their real recovery capacity that particular week. The right plan isn't the one with the catchiest name or the one your friend used to break 1:35. It's the one your body, with its history and its present state, can absorb and turn into real adaptation.

Key takeaways

• Volume and the longest long run predict performance, but they also predict injury if increased too quickly [PMID:32421886].
• Individual training response varies; leave room in the plan to adjust based on how your body responds, not just what's written on paper [PMID:41922043].
• Cardiovascular physiology changes with age and years of training — the plan that worked at 30 isn't automatically the right one now [PMID:40667749].
• The modern half marathon runner's profile is more diverse than the classic club runner many traditional plans were designed for [PMID:36326961].
• Practice your race pace under fatigue during long runs — pacing determines the outcome as much as the aerobic base does [PMID:30646638].

References

• Frandsen J, Aaroe M. Cardiac Effects of Prolonged Endurance Exercise in Young and Older Athletes. Scand J Med Sci Sports. 2025. [PMID:40667749]
• Nikolaidis PT, Knechtle B. Participation and performance characteristics in half-marathon run: a brief narrative review. J Muscle Res Cell Motil. 2023. [PMID:36326961]
• Fokkema T, van Damme AADN. Training for a (half-)marathon: Training volume and longest endurance run related to performance and running injuries. Scand J Med Sci Sports. 2020. [PMID:32421886]
• Nikolaidis PT, Ćuk I. Pacing of Women and Men in Half-Marathon and Marathon Races. Medicina (Kaunas). 2019. [PMID:30646638]
• Siebers M, Bizjak DA. Exercise biomarkers. Adv Clin Chem. 2026. [PMID:41922043]