Simon Knighton is something of an action man – but it wasn't always so.
The 62-year-old former oil industry boss is a fitness fanatic, who has run marathons and last year climbed Everest.
But 30 years ago he was addicted to cigarettes.
Now Mr Knighton is using his experiences to help others and encourage people to kick the habit for good.
He said: "I know what addiction is. It's coming in at midnight and hunting around your clothes for what used to be a half crown so you can buy a packet of cigarettes so you can have one in the morning.
"It's having bronchitis and making a decision on how to inhale so you don't cough but making that decision isn't the sensible decision."
Mr Knighton, a father of four and grandfather of one, became the chairman of Sirona when it was set up to run health and social care services in B&NES in 2011.
Before that he was a businessman and owned the Westfleet group, made up of five marine leisure companies.
He then sold them as part of a mission to "make a difference".
Last year the keen mountaineer climbed Everest from the Chinese side, raising £100,000 for the national charity Age UK.
This year he will be running the Bath Half Marathon in aid of SWALLOW – South West Action for Learning and Living Our Way – which supports people with learning disabilities.
He will also be challenging himself by climbing three Alpine peaks in a week – Monch, the Jungfrau and the Eiger – in July.
Mr Knighton said: "I wanted to put something back. I wanted to make a difference in the world in which I live and do it one person at a time.
"If you can make a difference to one person and then another and then another, you do start to make the difference.
"I changed my personal goals halfway through my life. I was brought up to believe that making money was what we were supposed to do but I realised that helping people was a lot more fulfilling and that's what I do."
Mr Knighton, who lives near Marlborough in Wiltshire, said: "My new year's resolution for Sirona is to get it to a point where it is recognised as the best employer, and for all our staff to be proud to work for Sirona. We were one of the first to sign up to the Workplace Wellbeing Charter.
"And with the challenge that I've made with the Chronicle today, I know we will have succeeded when I am outside of the area and someone says to me 'I hear Bath and north east Somerset is a great place to live and work'."
