Jamie Roberts is 30 years old later this year and has been playing for Wales since 2008. He has been taking and handing out hits in club rugby for even longer but, as he prepares for another Six Nations campaign, his passion for the game is burning with teenage intensity thanks to a break from the professional arena.

Roberts travels to Dublin with Warren Gatland's men to face Ireland on Sunday re-energised from a brief sojourn at Cambridge University, where he is studying part-time for an MPhil in medical science.

It may not feature in too many sports nutrition manuals, but student life has clearly had a positive effect on the centre as he prepares for the final third of a storied career.

His appearance for Cambridge in the Varsity Match may have ended in a "gutting" defeat and dead leg but his exuberance has been on show in the early stages of a Harlequins career that has so far tallied five appearances, one try and no defeats.

If he can replicate that form over the next six weeks then Ireland, and Wales' other Six Nations rivals, had better beware.

"You kind of feel like an 18-year-old again," Roberts told ESPN about his time back at university. "You take a break from pro rugby, you come back into it and you're vibrant, you're ready to go and you really chuck yourself into it at every training session -- you rediscover your youth a little bit.

"I've felt like that a little bit on the field over the last month and I feel re-energised and ready to attack that last third -- or second half, hopefully -- of my career with the same exuberance and enthusiasm that I had during the first."

Jamie Roberts during the 2015 Varsity match at Twickenham© David Rogers/Getty Images

At 29, and a veteran of 74 Wales caps, two Rugby World Cup campaigns and as many British & Irish Lions tours, Roberts admits that the break was well-needed.

"It was brilliant actually," he added. "I suppose I haven't really taken a break in the seven or eight years I've been playing professionally, so that was part of the reason for doing it -- to get back into studying and to play in that Varsity Match as well.

"It was great and I'll look back on it with huge, fond memories. I met some great people there and it's a wonderful rugby club and wonderful establishment, Cambridge. It's a really beautiful place and a chapter in my life I'll cherish for a long time." 

But with a move to the Aviva Premiership already agreed, and the Six Nations on the horizon, was he able to immerse himself fully into the student life?

"I did," the Harlequins centre says. "I made sure I socialised with the boys and that included going out on Wednesday nights with the lads after games and I made no excuse for not doing that.

"It was important I bought into it and it was great, actually. It was a bit of a throwback to my time in Cardiff [University] as an 18-year-old and was a wonderful thing to be able to do."

Roberts' time back in the lecture theatre has clearly left its mark. He wears a broad grin when remembering Monday and Friday nights spent cycling to training at Grange Road or the "unique experience [of] living in college and conversing with really clever people". 

He added: "It was a huge privilege. I'm very, very grateful for the opportunity to go and study there at the top university in the country."

That said, the experience has not diminished his determination to achieve greater goals with both club and country. Especially given the way that Wales were knocked out of the World Cup, following agonising defeats to Australia and South Africa in successive weeks.

"It was heartbreaking, especially after the glory of the England game and obviously disappointment of the Australia game," he said. "But that's rugby, you can't switch off and we did for 20 seconds in the 75th minute on the biggest stage.

"We switched off and they [South Africa] scored, and the game is done. That's the nature of the beast. We learn from it, we move forward as a collective, we look to improve our game."

And there is no shortage of confidence heading into the Six Nations. After all, and as Roberts noted, Wales have finished the last two post-World Cup tournaments with a Grand Slam.

"Look back at the last two World Cups, we've done pretty well after them," he said. "That's the goal to try and replicate that."

But does that put a certain amount of pressure on Warren Gatland's men?

"Putting pressure on ourselves allows us to achieve good things. There will be pressure on us and that's a good thing."

He added: "It's probably one of the hardest Six Nations to call in a long time and a lot of teams will be blooding younger players after the World Cup cycle and trying different things.

"But ultimately rugby is still rugby and you have to go out there and get the set piece right and get your basics right, and there's no doubt we'll be working well on them."

As Wales prepare for a campaign they hope will end in another Grand Slam, one of Gatland's key lieutenants will once again be Shaun Edwards. The defence coach has been an integral part of the squad's success over the last eight years, but had been out of contract following the World Cup.

Edwards ended months of speculation by signing a contract through to 2019 in December, though, and Roberts -- who made his Wales debut under the current regime during the 2008 Six Nations -- is delighted to be working with the former rugby league star once again.

"Anyone in the team will tell you Shaun is a great bloke, first and foremost he is a really good coach," he said. "He's been a huge part of what we've done since '08 when he came in.

"As defensive captain as well he's a guy who has taught me a lot in my career and I'm hugely grateful for that. He's given me a lot and he's a guy you really want to play for."