Anthony Joshua has kicked off his preparations for his upcoming fight with Kubrat Pulev by sharing a video with fans. 

The 27-year-old will come up against the Bulgarian in Cardiff on October 28.

He will attempt to defend his unified heavyweight titles with him currently holding the IBF, WBO, and IBO belts.

Pulev is the mandatory IBF challenger to Joshua, who will be looking to better his 19-0 boxing record.

He has also knocked out every opponent he has faced, so will be looking to do the same against Pulev.

A video shared by Joshua on Instagram shows he has ramped up his preparations ahead of the bout.

The Watford-born boxer has been working on all of his muscles, specifically his neck.

Despite his work, Joshua will have a tough test against Pulev, who comes into the fight at the Welsh capital with an outstanding record.

He has only been beaten once throughout his career - a 2014 loss to Wladimir Kitschko - and boasts an amazing count of 25-1. Pulev has also managed to knockout his opponent on 13 occasions in which he has earned a victory.

Watch AJ's workout in the video below.

Joshua himself comes into the fight off the back off his own fight with the Ukrainian. He won the WBA superweight and IBO heavyweight titles against the 41-year-old at Wembley Stadium in April.

Following the fight with Pulev, Joshua could potentially meet either Deontay Wilder or Joseph Parker for yet more unification fights in early 2018.

Tickets for the clash between Joshua and Pulev are nearly completely sold out with fans anticipating a highly-charged bout between the two in Cardiff.

Joshua has fought only once before in the Welsh capital and earned an extremely positive win as he looked to kick-off his boxing career. He won against fellow Brit Dorian Darch via a technical knockout in only his fourth professional match.