Ronaldo is currently aged 36 and rejoined the Red Devils in the summer transfer window following spells at Real Madrid and Juventus.
His return to Old Trafford has not gone as well as hoped, with United currently sitting sixth in the Premier League, though Ronaldo has proven to still be an elite goalscorer.
The Portuguese superstar has scored 14 goals in all competitions for United this season and has now stated his desire to continue to play at the top level for some time to come.
Ronaldo has an infamously strict diet and training plan, reportedly eating up to six meals a day and spending hours in the gym.
And he has now admitted that he hopes that combination will allow him to keep on playing into his 40s.
“I’ve been working and focusing more on working on my mind. I know my body will handle me because I have a lot of respect for it and I listen to it a lot,” he told ESPN Brasil.
“Life has to have important moments, for better or for worse, but when you fall you must have the strength to get up. I’m happy, I want to stay here and see what will happen.