Apologies for de-derailing this thread by interrupting the same two or three people stinking up every LR thread by only discussing doping, ethnicity or continent of origin, and instead try to discuss some factors that have changed how Narve can perform, and focus on something runners can actually discuss
The lastest episode of the Swedish Podcast "Spring snyggt - med Jesus och Manne" (Run pretty - with Jesus & Manne) did a phone interview with Narve about his fantastic Bislett result. The key takeaways from that interview:
The first, unsurprising aspect: Narve has greatly benefitted from Gjert not coaching Jakob, Filip or Henrik, as it has provided much improved individual focus and adaptations.
The second aspect, which is surprising: While Gjert, and Narve still are in the double threshold crowd, they have made a somewhat radical departures from the model the Ingebrigtsens have been known to follow. Narve runs at least some proportion of his morning threshold sessions on trails/in forests with no GPS, no watch and no lactate measurements. Gjert was hesistant of this at first, because it couldn't be measured. The same also relented, because he saw that it kept Narve both happy and injury-free, and now trusts Narve to be able to train by feel.