Strength gains maybe in lower doses as your body is able to uptake and process more protein and carbohydrates. In higher doses, say more than 50mcg day, I think you will notice the opposite to be true. Dont know about the muscle fiber change.
Hi,
it can't change slow twitch fibers into fast (muscle tissue remodeling). What T3 does is increase in nutrition uptake ( increase metabolism )... and because of this metabolism increase body has also higher ability to react ( faster burning of ATP ). Athletic sprinters basically use T3. Liothryonine is used to help accelerate the basic metabolic rate before competitions. The purpose is to reduce sluggishness and increase quickness. Two 25mg tablets are taken one hour before competition and BANG you are little faster. Or stronger before lifting competitions.
Hope it explain everything to you