Jelly Roll 's 41st birthday had him on cloud nine, but the only high he got was from a solid run.

The rapper posted a video on Instagram Thursday, showing him mid-workout ... "I used to drink and do cocaine on my birthday. I used to do codeine and pills on my birthday. Now on my birthday, one of my best friends wakes me up and says, 'Let's go for a f**king run.'" Getty

JR had already worked up a sweat as he jogged alongside his buddy, Cam Hanes .

According to a separate post from Cam, the two were "crushing a 5k."

JR said, "If you didn't enjoy your birthday this year, you can change it by next birthday, baby!" Getty

The "Son of a Sinner" artist has reportedly lost nearly 200 pounds after, at one point, reportedly weighing as much as 550 pounds.

And his waistline isn

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