Williams has been a professional player for around 11 years now, having formerly played his rugby at Pontypridd before joining Cardiff in 1999. He admits that these days he finds training "a bit of a grind", despite being fully aware of its benefits.
"I'm naturally a very competitive person - I think all rugby players are - and what I really love to do is go out and play rugby. I don't really want to train so hard that there's nothing in the tank for the game at the weekend."
Williams believes the Blues have had a good season that would have been all the better if they had overcome fellow Welsh side the Ospreys in the semi-finals of the EDF Energy Cup.
"There is a difference between losing and playing badly. If you've given as good as you can and you were beaten by the better side, that's easier to take. If you don't think you've given your best, that's when the questions start, that's when you get all the ifs and buts, and that's the worst possible scenario for me. I felt like that after the EDF game. Now we are still in the hunt for the Magners League and all the boys are focused on the last two games."
Martyn is also starting to look at life after rugby. He's pretty sure he can't see a future in commentating ("No, that wouldn't really be for me"), and he doesn't want to plunge straight into coaching. "Scott Johnson (the former Wales skills coach) told me the most difficult thing to do is to go straight into coaching. He said you should try to freshen your mind up, gain other experiences."
In preparation, Williams, has set his sights on a career as a commercial banker when he hangs up his boots and is working one day a week at HSBC's commercial centre in Newport.
The Cardiff Blues flanker has been given a two-year contract with the bank where he will be trained as a commercial manager through a programme of shadowing other bank colleagues and coaching. Through this process Martyn is working towards becoming a fully qualified commercial manager in his own right with the global bank. Martyn said,
"I am really excited about my new role in HSBC and in taking on a completely new challenge. It is a privilege to be associated with one of the world's leading banks."
"I'm really enjoying it," he said. "I was six months into my A Levels when I turned pro, so I left and never finished them. I have two years left on my Blues contract, when I'll be 33-years-old. I might continue playing, but I'll have to decide in 12-18 months' time what I'm going to do."
It sounds like he might enjoy a life outside rugby.
"I'm looking forward to a bit of normality. I have two young children, and I can spend lots of time away from home. I know I'll miss the buzz and the adrenalin, but there will be new things to do."
And how will he remember his career?
"I'll be happy if, when I retire, I can believe that I achieved my potential and did as much as I can in my career. When I was first in the Welsh side, it was said that I was quite small for a number seven, so I set out to prove those people wrong. But as a number seven, you can only be as good as those around you. There are some days when there is nothing you can do to change the outcome. But when you do have days when you can, you should make sure that you do make the difference."
Martyn Williams factfile
Family: Married, with two children, aged four and eight months
Honours: Capped at every junior and youth level, Williams has over 50 caps for Wales and played on the British Lions tours of Australia in 2001 and New Zealand in 2005
Best mates: "Outside of rugby, the guys I grew up with in Pontypridd. In rugby, it's Alfie, Gethin Jenkins and Tom Shanklin"
Toughest opponents: "(All Blacks Ritchie McCaw and Jerry Collins - once-in-a-generation players. And the England back row of Neil Back, Richard Hill and Lawrence Dallaglio"
You probably didn't know: That Martyn was also a talented footballer, playing centre half for the Welsh YMCA U16 side