Heavyweight boxer Joshua, who is still riding the crest of a wave after his stunning knockout victory over Francis Ngannou in March, was course-side on sponsorship duty as he handed out drinks and chatted to runners.

The Brit could be seen donning a dark blue Lucozade hoodie, with one video shared by the drinks brand showing him giving some tips to one runner on how to reach the end of the race.

Anthony Joshua was seen handing out Lucozade and providing encouragement to London Marathon runners on Sunday

The British boxer shared a heartwarming moment with one runner, who had been struggling

‘Listen, this is where you dig deep,’ AJ can be seen telling a runner as he embraces the competitor, who is dressed in all-orange.

‘I’m just mentally blown up,’ the runner’s response.

Joshua continues: ‘Yeah, but listen. If you know you’re mentally blown up, it’s fine. It’s all in the mind, right? So if you’re feeling like you’re blown up, rebuild now.

‘Take a quick little recap, two minute walk, finish the race bro. Control your thoughts, control you mind. Let’s go.’

The runner, who can be seen gratefully receiving a cup of Lucozade from Joshua, then fist bumps the heavyweight and continues running.

A number of other competitors also stopped for some words of wisdom from the two-time world champion

Joshua is still waiting to find out his next in-ring opponent having beaten Francis Ngannou (right) in March

Joshua continues to wait to find out his next opponent for the boxing ring, with it expected he will take on the winner of Tyson Fury’s unification bout against Oleksandr Usyk.

The two heavyweights will do battle in Saudi Arabia on May 18, with Fury set to make ‘some adjustments’ for the bout as he looks to recover from a narrow win over Ngannou.

The Brit scraped past the former MMA star in October, leading to fans calling for him to be wary when he faces Usyk, before a potential clash for the ages against Joshua to follow.