The 21-year-old from Christchurch said getting to the Tokyo Olympics was a gamble, which factored into her decision.
Her senior year at American college Boise State was curtailed by a ruptured Achilles tendon and the coronavirus outbreak.
McGregor said the timing was right to call time on her career.
“It was definitely a really difficult decision.
“I’m usually someone who is very logical and decisive but this one took me a couple of weeks.”
“I was always hoping to come back and do medicine here so there wasn’t much point to go back for a season that wasn’t what it normally is.
“After I made that decision I had to think about the Olympics and looking at the news, there’s no guarantee there will be a vaccine or that it will even go ahead so that made my mind up.
“It’s definitely strange. I put together a video for my social media and that allowed me to go back over my career and that was really therapeutic and helped me let go.
“I know that I’ll be able to look forward to what is next and know that gymnastics has helped prepare me for what is next.”
McGregor said while it was great to compete at the 2016 Olympics in Rio de Janeiro, she was most proud of her dedication and drive to train, which was often done alone.
“It blows my mind I had the motivation to achieve the things I have because it’s really hard.
“I was working between four and seven hours a day in the gym.
“As an athlete, you look at the hours and hours you put in the gym and that’s the work no one sees.
“The competitions are a minuscule part of everything I did, so I guess I’ll look back on that time training with a lot of pride.”
McGregor said she is in discussions to do some coaching this year before her medicine studies begin in 2021.
