Colin Kaepernick is still busting his ass to get back in the NFL ... the ex-49ers superstar just posted a workout video -- and it's INTENSE.
The video shows Kaep getting after it in the weight room -- there's push ups, bench presses, rows, tricep pulldowns, dips ... the guy is CLEARLY still in fantastic shape.
And with the NFL season starting ... it's obvious Kaepernick wants people to know that despite a settlement in his collusion case with the NFL -- he's still working to make a roster.
In fact, the video starts with the number 889 -- the amount of days Kaepernick says he has been "denied" a job in the league.