Jagger is going to turn 70, but it is thanks his intense fitness regime has kept him fit and going.
Styles got chatting to Torje Eike, Jagger's long-standing trainer and physio at the Stones' show in Washington last month. That's when he thought of taking up ballet, reports thesun.co.uk.
"Harry wants a career spanning decades like Mick's and to have that he recognises that fitness, health and developing his body is the key. He spoke to Torje about Jagger's intense routine of kick-boxing, running, weights and, most importantly, ballet," said a source.
"That's the Achilles' heel in Harry's training. He can't dance and neither can any of the 1D boys - their choreographer recognised early on that they shouldn't dance on stage," the source added.
Ever since One Direction appeared on "The X Factor" in 2010, it has been clear that dancing is not their cup of tea.
The boys are already indulging in a fitness regime while away on tour, working with personal trainer Mark Jarvis doing cardio, hitting the weights and using state-of-the-art gym equipment.
But Jarvis' boss Ramzy Khachik advises learning to be more graceful will be good for the band. "Nobody works harder than ballet dancers. It's all about grace, stance and strength. Harry sees how supple Mick is, how he manages to stretch his body and do contortions.
"It's a brilliant art form and will get more grace into his movements - if you're graceful you can get away with minimalistic moves, which is what their choreography is about," said a source.