Why is my marathon plan mileage lower than expected?

Why is my marathon plan mileage lower than expected?

By Dr. Sean Radford23rd February 2026

Excepting cases of severe data errors, this will be intentional. TrainAsONE prioritises consistency and injury prevention over 'hero' long runs. Statistical evidence shows that total weekly volume is a much better predictor of marathon success than the distance of any single training run.

TrainAsONE focuses on the minimum effective dose to achieve your goal safely, i.e. injury-free. Data shows that 'more' is not always 'better', and total consistency is far more important than high peak mileage.

Here are some data-driven details to think about...

Weekly Mileage

Research into marathon finishers shows a surprising lack of correlation at certain levels. Specifically, there is no statistical difference in the lower range of peak weekly distances achieved by 3.5-hour marathon runners compared to 5-hour runners. If you are hitting 45 km/week, this does not mean that your 3:15 marathon target is not achievable - statistically it is. The AI prioritises the quality and specific physiological stimulus of your runs rather than just adding 'junk miles' to hit an arbitrary target number.

The "Long Run" Myth

There is no statistical difference in the longest training run of an elite athlete versus a 5-hour marathon runner. As an isolated metric, the single long run has no bearing on your finish time. The 'magic' happens in your total cumulative volume and mix of workout types.

The 40% Rule

Approximately 40% of runners suffer a significant injury during marathon training. Around half of those do not make it to the start line (Did Not Start - DNS) and of all marathon runners, around 12% Did Not Finish (DNF) due to injury. To ensure you make it to the start line, our AI monitors your 'niggles' and recovery metrics. If it detects a risk, it will hold back volume to try to prevent things escalating.

What should I do?

If you feel the volume is "low," it is because the system has calculated that this is the safest and most efficient path for your current fitness and injury profile. Trust the consistency; it is the total work done over months that builds a marathoner, not a few high-mileage weeks.