Key Takeaway
Elite endurance athletes train 80% low intensity (Zone 1-2) and 20% high intensity, with minimal time in the moderate "threshold" zone.
Summary
Stephen Seiler's influential analysis of how elite endurance athletes actually train revealed a consistent pattern across sports: approximately 80% of training is performed at low intensity (Zone 1-2), with the remaining 20% at high intensity.
This "polarized" distribution contrasts sharply with how recreational athletes train, who often spend too much time in the moderate "threshold" zone that's too hard for optimal aerobic development but too easy for maximal stimulus.
The research suggests that high volumes of low-intensity training build the aerobic engine, while targeted high-intensity work develops race-specific fitness.
Methods
- Analysis of training logs from elite athletes across sports (running, cycling, rowing, cross-country skiing)
- Retrospective examination of training intensity distribution
- Comparison of different periodization models
Key Results
- 80/20 distribution observed across endurance sports
- Low-intensity training volume strongly correlated with performance
- "Threshold" training overrepresented in recreational athletes
- Polarized approach superior to threshold-focused training
Limitations
- Observational data from elite athletes
- May not directly apply to recreational athletes
- Causation vs correlation questions
- Definition of training zones varied across studies