But now he has been tipped to secure a Lions spot after signing up for double training shifts.
In the last 272 days since pre-season began in July, Ospreys star Jones has doubled his usual fitness regime - including training sessions on his own and on his days off.
Ospreys conditioning coach Mick McGurn said: "I've never seen anyone work harder than Adam. He's had to take a lot of flak in the past but he's an incredible man.
"He wanted to improve his fitness and his weight has come down because of the work he's put in - he's done an extra 200 sessions.
"Under Steve Hansen he was a 30-minute player but now he can last the distance.
"He's increased his strength and improved his speed and I'm delighted for him.
"The players do a seven-minute drill at the Ospreys where they have to sprint 40 metres inside seven seconds before jogging 50 metres for the next 13 seconds.
"Adam wouldn't have been able to last the pace in pre-season but now he has no problems. I just hope he gets his just rewards with a Lions call up."
Fitness expert McGurn boasts an impressive CV including masterminding a treble triumph with rugby league giants St Helens and three Triple Crown's with Ireland, as well as working with Irish WBA super-bantamweight world champion boxer Bernand Dunne.