To improve in running and avoid injuries, it is essential to run the majority of the time at a very easy pace (fundamental endurance), where you can hold a conversation without getting out of breath, rather than always training at high intensity.

noli's read

This advice is based on the concept of polarized training, which is widely documented by researchers such as Stephen Seiler. Studies, including meta-analyses on endurance athletes, confirm that dedicating approximately 80% of one's volume to low intensity (Zone 2) promotes lasting physiological adaptations, such as an increase in stroke volume and mitochondrial density. The risk of injury linked to excess intensity is also well-supported by observational studies showing that high-intensity volume is a major risk factor for overtraining. The use of the talk test is a validated practical method for estimating ventilatory thresholds without complex equipment. However, stating that this applies to 'everyone' warrants nuance: while the principle is sound, the exact distribution (80/20) may vary depending on the level of practice and specific goals. The creator rightly simplifies complex physiological concepts to make them actionable for the general public.

the sources

1. 1Rosenblat MA, Perrotta AS, Vicenzino B 2019
2. 2Silva Oliveira P, Boppre G, Fonseca H 2024
3. 3Menshikova EV, Ritov VB, Ferrell RE, et al. 2007