Adaptations & fibre recruitment

So I was watching a video and it said that in the first few weeks of any training program the main change is that your body gets more efficient at recruiting fibres and only after does it start to have more physiological changes. I know this is the case for weight lifting, but is it really the case for aerobic / endurance sports?

Hmmm. I’d have thought increased blood plasma volume would be one of the first things to happen …

Seems reasonable to me. When they say “main change”, it is implying other changes are happening, so the types of adaptations are on a continuum. For cycling, you still have to become more efficient at using the necessary muscles. It would make sense that this is the quickest thing to improve. One would still be improving aerobic ability at some percentage, just not as much as fiber recruitment in early stages.

And one of the first to reverse very quickly.

Presumably the first part of detaining will be loss of fibre recruitment?