Amir Khan has arrived in Manchester ahead of his clash with domestic rival Kell Brook on Saturday night after training in Omaha, Nebraska and the Colorado Springs.
Speaking to Sky Sports, Khan claimed training high up in the mountains has plenty of benefits.
"The altitude in Omaha and Colorado Springs was very, very difficult. We've just got back, so still got the benefits of doing it," Khan said.
"I've done a 12-round spar and an eight-round spar, finished off with the eight-round spar and it felt so easy!
"The oxygen, it just felt like there was too much of it.
"It's amazing to know that I've got the fitness on my side. I've got the health, I've got the strength and I've got the team around me as well.
"They've got me in good shape. We're going to go into this fight and win this fight.
"We've been focused in Omaha, up in the mountains in Colorado Springs, focused on our training. We don't care what Kell and his team are doing."
When it came to discussing Brook, Khan believes the occasion is becoming too much for the Steel City fighter.
"His confidence is brittle, definitely," Khan claimed.
"And I can see right through him. You can see how he reacts when I talk to him. You could see he really dislikes me and hates me, which is normal. We're going to be fighting each other come Saturday.
"But I just think it's getting to him a bit too much where it could definitely throw his game-plan out the window, where he's going to go into a fight, guns blazing, make mistakes and get caught himself."