I have heard about testosterone thing after waking up in the morning, but not so much after naps.
I read it in an article a while ago and I am trying to remember but there is a lot that goes on during a full night's sleep: Growth homone levels, testosterone levels, building muscle tissue, healing, etc.
For what I understand, naps do not have that same affect. They do help as far as energy levels go, but nothing happens drastically that's hormone related unlike sleeping a full 8 hours at night.
Bottom line, if you have a good meal and are looking at training within the next 3-4 hours, taking a nap would help your over all focus and energy in the gym.
The only time where a nap would affect hormone levels would be if you are very sleep deprived and you took a nap. Your body wont care that it's a nap and it will treat it as if you are going to sleep fully.
As to where if you are sleep deprived, taking naps would be much more beneficial then if you weren't because as we all know, sleep deprivation is not ideal when you are training all the time.
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