Taylor Swift's personal trainer claimed she works out so hard, other people would "probably throw up" if they copied her sessions

He told Vogue.com: "It's really hard, some people would probably throw up or have to lay down on the floor if they trained like her...

"Taylor is the most resilient person I have ever met. It's super-inspiring to see her consistently overcome obstacles and become better and stronger in the end.

"This also translates into her training and throughout her workouts. I give her a difficult exercise or challenging workout, not only is she able to complete and push through it-but she also perseveres, moving forward into the next exercise. This ultimately makes her stronger, better, and faster."

Kirk - who has also worked with the likes of Hugh Jackman, Tom Holland, Kaia Gerber and Karlie Kloss - helped Taylor prepare for her 'Eras' tour as if she were a "professional athlete", with two-hour sessions six times a week during breaks from her concerts, and at least two workouts a week while she's on the road.

He said: "It's tailored. We approached her training for the Eras tour with the mindset like a professional athlete. There was an 'off-season' when she wasn't touring and 'in-season' when she was.

"When she's not touring, we're in the gym up to six days a week for sometimes two hours a day.

"Taylor trained during the entire tour. We would average two times a week. In-season training was more about maintenance, and so it was more like stability, mobility, biomechanics."

The trainer worked with Amin Javid, a chiropractic physician, to implement recovery techniques for the 34-year-old singer.

He said: "If you've seen the show, you know how intense it is physically. Imagine doing that three, four days in a row and then you finally have a few off days and you're still showing up to gym. That's Taylor."