Mikaela Mayer has explained the change she made that she believes makes her a more dangerous fighter.
The American fights this weekend in Liverpool as she takes on IBF welterweight champion, Natasha Jonas (live on ESPN+ for US viewers).
Mayer said that should she emerge with the belt, she will be obliged to take part in a rematch.
"This is a big fight, you definitely have that big fight feel but these are the fights that I want to be in," she said to Sky Sports."I want the name Natasha Jonas, I want to be in her hometown, I want to be in a huge arena like the M&S Bank Arena, i want the spotlight because I feel like that brings out the best in me.
"It [opens the door] of a rematch, contractually, so there is that but one fight at a time.
"I have got to beat Natasha Jonas twice. That is my main focus."
Mayer thinks that stepping up to 147lbs gives her a much better chance of fighting well.
She explained: "I am a lot more natural at this weight. I think a lot of people are taken back by how big I look but what they don't understand is it took a big toll on my body to keep cutting down to an unnatural weight at 130.
"Cutting all the way down and fluctuating in between and having such an extreme, that does a lot to the body and the hormones.
"This is the first time I have allowed myself to have that weight on and also build muscle.
"This is the best I have ever felt and we are close to the weight already. I am just excited to get in the ring and show what the new weight does to me.
"I am an athlete and this is my body and I know my body well. I know I have been doing everything right.
"I am OK with the extra weight. Being skinny all the time and on the calorie deficit was not fun.
"For me, to cut down to 130, it was a 10-week calorie deficit and camp would be really hard so I am enjoying boxing a lot more now.
"I think clearer, I am happier, I am more confident. Trust me, I am a better fighter for it."
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