My marathon training plan does not include 20 mile (plus) runs. Why?
Traditional marathon plans often mandate several 20-mile runs, but this "rule" is largely based on studies of elite and high-volume club runners (those finishing in under 3 hours). For the vast majority of modern marathoners, these extremely long runs can actually be counterproductive, leading to excessive fatigue and a significantly higher risk of injury.
At TrainAsONE, we prioritize efficiency and injury prevention. Instead of following a one-size-fits-all distance, our AI determines the most effective training volume for your specific physiology. For many, this means replacing a single, exhausting "mega-run" with more effective back-to-back sessions or "shorter-long" runs that build endurance without the 20-mile "hangover."
Why "Old" Marathon Science is Often Misleading
Most training "rules" come from studies that don't represent the average runner. Consider these facts about the research used to justify 20-mile runs:
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The Elite Bias: The average finishing time in these studies was 3h 07m. In contrast, the 2024–2025 global average was approximately 4h 15m (males) and 4h 56m (females).
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The Gender Gap: While 51% of marathoners are female, less than 30% of research participants in these historical studies were women.
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Age Discrepancy: The average marathoner is 40+ years old, yet the average study participant was just 35.
The Data: How TrainAsONE Users Compare
Our internal review of runners who completed a TrainAsONE marathon plan demonstrates that you don't need 20-milers to excel:
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TrainAsONE male finishing times ranged from 2h17m to 8h20m, with an age range of 19 to 75 years;
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TrainAsONE female finishing times ranged from 2h36m to 8h58m, with an age range of 20 to 68 years;
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68% of TrainAsONE users finished their marathon faster than the global average.
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On average, TrainAsONE users ran 20 minutes less per week than the global average.
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On average, their training involved 6 km less total volume per week.
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On average, their longest training run was 3.5 km shorter than those on traditional plans.
The TrainAsONE Approach
A 20-mile run for a 3-hour marathoner takes roughly 2.5 hours. For a 5-hour marathoner, that same distance can take over 4 hours — an effort that causes massive physiological damage and requires weeks of recovery. TrainAsONE protects your "race tomorrow" potential by ensuring your long runs provide a stimulus for growth, not a recipe for burnout.