Training three times per week by combining endurance, interval training, and long runs is sufficient for long-term progress in running.

noli's read

This approach is based on the principle of periodization and intensity balance, which is validated by sports science. Studies (e.g., meta-analyses on polarized training, such as those by Stephen Seiler) show that a mix of low intensity for aerobic base and high intensity for cardiovascular capacity is optimal for performance. Limiting frequency can also reduce the risk of overuse injuries, which are often correlated with increasing mileage volume too quickly. The argument is solid, as long-term consistency often takes precedence over pure volume for the amateur runner. It is not exaggerated, but it assumes adequate intensity in the chosen sessions. There is no evidence that higher volume is useless for elite athletes, but for the general population, this model is an excellent compromise between progress and personal life.

the sources

No named source held this one up — that absence is part of the verdict.