In the latest video put on Instagram, Tyson can be seen growling through a workout hitting the pads. "Anything is possible when you are smart about it. Train Smart. Recover Smarter," he wrote as the caption.
Towards the end of the video, he can be seen saying: "I am back." View this post on Instagram
Tyson, who became the youngest heavyweight champion of all time when he defeated Trevor Berbick in 1986 aged 20, won 50 of his 58 professional fights before retiring after his loss to Kevin McBride in 2005.