More Tempo Running – A Key Ingredient To The Kenyan Success
https://www.sweatelite.co/more-tempo-running-a-key-ingredient-to-the-kenyan-success/

Deliberate Practice in Training Differentiates the Best Kenyan and Spanish Long-Distance Runners
(Arturo Casado, Brian Hanley & Luis Miguel Ruiz-Pérez)
https://www.researchgate.net/publication/337260599_Deliberate_Practice_in_Training_Differentiates_the_Best_Kenyan_and_Spanish_Long-Distance_Runners

(Specyficzne jednostki treningowe wyróżniają najlepszych kenijskich biegaczy długodystansowych na tle biegaczy hiszpańskich)

The Role of Deliberate Practice in the Acquisition of Expert Performance
(K. Anders Ericsson, Ralf Th. Krampe, and Clemens Tesch-Romer)
https://www.researchgate.net/publication/224827585_The_Role_of_Deliberate_Practice_in_the_Acquisition_of_Expert_Performance


https://pubmed.ncbi.nlm.nih.gov/17402388/

https://journals.humankinetics.com/view/journals/ijsnem/aop/article-10.1123-ijsnem.2020-0034/article-10.1123-ijsnem.2020-0034.xml#d96844236e404

https://www.researchgate.net/publication/336660301_Is_Coffee_a_Useful_Source_of_Caffeine_Preexercise