At 6-foot-5 and 289lb JJ Watt is a terror on the football field - recording more than 20 sacks and forcing four fumbles for the Houston Texans with his explosive speed and power last season.

Now the NFL defensive end flaunting his incredible athletic process off the field.

On Monday he released a video that shows him making an incredible 61-inch vertical leap.

The standing box jump - a popular CrossFit workout move - is billed as a personal best.

JJ Watt performed an incredible 61-inch box standing box jump. An impressive feat for a man who weighs nearly 300 pounds

The Houston Texans defensive tackle released the video as part of his announcement that he has signed an endorsement deal with Reebok

Watt, already a legend in Houston for his performance both on the field and off, leaned down after his jump and declared: 'Must have been the shoes, baby!'

The clip, impressive as it may be, appears to be a stunt for Reebok, which announced on Monday that they had signed the NFL star to a shoe endorsement deal.

After completing the jump, Watt, 26, screams and declares: 'It must have been the shoes, baby!'

The video was posted to YouTube by Reebok and pushed the lime-green $110 ZPump Fusion shoes that Watt wears for the stunt.

Watt, who has been building a superhuman reputation both with his on-the-field heroics and off-the-field community work, will be the face of the company's 'Be More Human' ad campaign.

Don't mess with Texans: Watt, 6-foot-5 and 290lbs, has made a reputation for himself as a defensive terror on the football field

'The ability to have input in the products I will be wearing is what I love, letting them know what I think they can help me with,' he told the Houston Chronicle.

A survey of YouTube reveals only one higher standing box jump - 64 inches recorded by a personal trainer in Wisconsin.

However, none of them are nearly as enormous as Watt, who managed to leap more than five feet in the air despite weighing nearly 300 pounds.

At the end of the season, Watt signed a six-year, $100million contract with the Texans that included a $10million signing bonus.