Early adaptations to strength training are primarily neural, leading to increased strength without immediate changes in contractile proteins or muscle size.

“The early adaptations to exercise, especially strength training, are hedged towards the nervous system. No question about it. People always say central nervous system, but it's probably more peripheral, right? Whatever, semantics probably, but pedantic. It's nerve, if you train today, tomorrow morning you're not going to wake up with a actually increase in contractile proteins and muscle. Your muscle might be a little bit bigger due to some acute swelling, but you could have a pretty acute that persists, change in the nervous system we'll call it, that allows you to be stronger, like within a couple of days.”