Watch his effort below.
"When @willsmith challenged me to get active, I pretended to do some pull ups," Branson wrote to his followers.
"But this time I did it for real - here’s the proof. I got to six pull ups before the @strivechallenge, now I’m up to 10, aiming to get to 20 this Autumn"
Fans were quick to get around him for his efforts: Bear Grylls congratulated him on his feat while the comment section was flooded with messages of support from followers.
It's no secret Branson does his bit to stay in shape.
“I get up at 6 in the morning and play a hard game of singles tennis with somebody better than myself,” Branson told Men's Health last year.
“Then if the wind is up I’ll go kitesurfing and I’m just beginning to do a little bit of weight training to strengthen a body that’s getting on a bit in age.”
If he's busy juggling multiple businesses and can still find time to exercise, i'm sure you have a spare 45 mins.
So where does Will Smith fit into this?
Virgin Sport has partnered with JUST Goods, a company founded by Will Smith's son Jaden, ahead of the Strive Challenge. Their goal is to eliminate 19,000 single-use plastic bottles from the event.
In the end, they managed to remove an additional 40,000 plastic bottles from the route, replacing them with fully recyclable paper cups.