This ridiculous core workout looks like the stuff of actual nightmares

Demetrius Crawford doesn't take days off.

The 30-year-old remains hopeful of making it big in the NFL and he can never be accused of slacking off as his workout videos have shown off Crawford's work ethic in no uncertain terms. A running-back by trade, Crawford attracted plenty of attention in his senior season with Montana State but had to make do with the briefest of stints in the Indoor Football League with the Tri-Cities Fever after going undrafted in 2009. CFL outfit the Saskatchewan Roughriders signed him to a deal in 2012 but, unfortunately, he was released before the season kicked off. And while he awaits the elusive knock on the door from the NFL, Crawford continues to prove his fitness and determination on a regular basis via social media. Training out of the DreamChasers Elite gym in California, Crawford works with top-level athletes on a daily basis and, by the looks of things, he puts most of them to shame in the workout room. Only last week the 2004 CVC offensive back of the year showed off unfathomable core strength in this Instagram post that has since gone viral. https://www.instagram.com/p/BT86LLBAsdU/?taken-by=k1ngcrawford&hl=en If you fancy giving this a go, more power to you. Because that genuinely looks physically impossible to endure.