Conor McGregor has shown off his body transformation down the years to his MMA fans by posting a throwback photo ahead of a championship fight seven years ago.
' The Notorious One ' posted a throwback snap on social media of him at the weigh-in before his fight with Dennis Siver at UFC Fight Night in 2015, showing off his once skeletal physique.
He captioned the photo: "7 years ago. Still here rocking championship weight."
McGregor won that January fight against Siver via TKO in the second round.
The Irishman has since enjoyed some body transformation after continuing his meteoric UFC rise, but perhaps none more so than in the recent months.
Following his defeat to Dustin Poirier last summer, the combat star has put on an astonishing two-and-a-half stone of muscle.
The feat is even more remarkable given he is recovering from a broken leg sustained in the loss to the American last July.
According to the website Strengthlog , McGregor's increased muscular mass in such a short period of time should be almost impossible to achieve.
The site claims that an average beginner would normally be able to put on four to seven pounds of 'fat-free mass' over a period of three months with the same plan; in six-months McGregor has gained 34lbs.
The UFC star's personal trainer, Alejandro Celdran, told Spanish outlet AS about the methods the pair have implemented.
He revealed they focused on hypertrophy training - which focuses on growing the muscle size - and they did this by adopting a method of high volume training rather than frequency.
McGregor would take part in four weekly training sessions to target each muscle group and prioritise free weights and supersets over machines.
Ensuring McGregor had the correct diet and protein intake was also key to reaching his desired physique.
The former champion is keen to return to the octagon this year, but UFC president Dana White has ruled out the icon receiving a title shot upon his return.
"We've got to see how all these fights play out [but] first of all we have to see Oliveira face Gaethje," White told BT Sport . "And then determine who is next for the title.
"I don't know the answer to those questions in terms of who will fight who but any way you match them up it is all good. There is a lot of different things we can do in that division.
"Even as long as Conor has been out with the type of injury who knows how long he is going to be to come back and be here. He needs to take time and let it heal get back to one hundred percent. Then we will work out what is next for them."