The 20-year-old had a breakthrough season for the Red Devils in 2021/22, where he featured in 27 games in all competitions.
It was an underwhelming season for United, where they finished sixth in the Premier League, but Elanga provided some hope for fans.
This summer has been a time for the club to reset with Erik ten Hag being appointed as manager and tasked with turning things around at Old Trafford.
While the summer is a time for most footballers to get away and relax, a number of United players have been putting in the hard work in the gym before pre-season even starts.
Elanga has been working hard and looks pretty ripped in a video posted on Twitter.
It shows the winger lifting weights, doing box jumps and working on his explosiveness - the clip has been viewed more than half a million times.
Speaking to the Manchester United website, Elanga said: "You know what? Honestly, in the youth team, I wasn't really jumping and scoring many headers but I think I've scored more headers for the first team than I did in the youth team.
"So it was something I worked on a lot last summer. I went away for a bit, working with one of my personal coaches, Tom [Joyce] and he helped me a lot."
"We worked a lot on jumping and other aspects of my game," he added. "I feel like, last pre-season, you could see that I've been working on those areas and, like I say, it's all about keeping on improving, getting better. My motto is always keep improving as I know I will never be the finished article. I can always improve and find areas where I can get better at.
"I think it shows my dedication and my mentality as well. Like I say, mentality is one of my strongest assets. I've been through a lot of things, even earlier on in the season as well. but I've not let it affect me. I'll keep pushing and keep working hard."