IT WAS a hypnotist who turned me overnight from a chain smoker to a committed non-smoker 15 years ago, which was an important step on my journey to middle-aged sporting participation. So when I received a letter recently from a hypnotist offering to help me to compete in the London Triathlon, I did not immediately throw it in the bin marked “green ink and mumbo-jumbo”.

The letter was from Tim Smale, a Times reader who noticed from the footnote to my articles on sporting greats that I was doing the triathlon to raise funds for the Leukaemia Research Fund. His son, Joe, had the illness diagnosed in 2000, aged 2. Tim said that, although Joe is now off treatment, if not yet finally in the clear, the experience had given him a new take on his own life. He gave up the corporate and media world in which he had been a burnt-out executive and trained in what he likes to call “mind coaching”; last year, he set up his own company, Mindworks.

It is the public image of hypnosis that probably stops him calling that particular spade a spade, but “mind coaching” or not, it was a couple of hypnosis sessions I booked in for after he offered his services to me and any other members of the 160-strong Leukaemia Research triathlon team I was leading. Of course, it is impossible to establish in any exact way what, if any, effect those sessions had upon my subsequent performance, but I am strongly of the view that they had some effect for the better.

I am proud and boastful enough to claim the bulk of the credit for completing the 1,500 metres swim, 40 kilometres bike ride and 10 kilometres run in 2hr 43min — far quicker than what I considered to be my highly ambitious 3hr target. After all, it was my arms that had to power through the water, my legs that had to pump up and down the two laps of the bike route from Beckton to Tower Bridge, including the joyous breaking of the 30mph speed limit in the Limehouse tunnel, and my body that had to drag itself round the 10 kilometres run when every bit of it was screaming to stop.

But even at my level, you need support. I was lucky to have a fantastic coach, Steve Loraine, the former elite triathlete and a relative of mine, who set me specific training schedules over seven months, all geared to peaking last Sunday, and who lured me into a new and enjoyable obsession, namely the resting heart rate.

I also got terrific support, in terms of kit, advice and practical help — not least the immediate supply of a new bike when my old one was stolen — from Triandrun, triathlon specialists, and enjoyed an invaluable coaching session from its waterborne counterparts, Swim for Tri, which kindly educated me in the washing machine effect created by hundreds of swimmers fighting for space in the water at the start.

Of course, no one thinks it odd to have coaches, schedules and expert advice. But for the majority taking part in mass-participation events, the mental side of things will be every bit as important as it is for the top competitors. Indeed, given the lack of natural talent and the fact that the less talent you have the longer you will be on your feet and suffering, you could argue that the mental side is more important for the amateur.

So I felt neither odd nor furtive to be taking up Smale’s offer and heading to his office in the West End of London for my first consultation some weeks ago. It consisted of a detailed chat about my past, my present, my likes and dislikes, my hopes and fears about the triathlon event.

Then it was into the reclining chair, dimmed lights and soft music and Smale talked away and at some point, apparently, got into my subconscious. I thought it lasted about five minutes. In fact, I was in the chair for half an hour. Another session followed a week later. This time he recorded it and produced a CD, which I could listen to at home when I wanted to relax.

It was fairly classic hypnotherapeutic stuff; talk of nice places, good memories, family, sunshine and cooling drinks of water. But he included plenty of references of specific points of anxiety relating to the training and the day itself. And he put in a few specific trigger words or phrases that he urged me to say to myself whenever I felt I was weakening or panicking. The one that lodged was “better, faster, stronger”.

His main clients are business people frightened of making speeches in public or stressed about workload. His aim is “subconscious motivation”, helping people to block what may be negative conscious thought by visualising something positive to put in its place.

I have played such mental games before, as I recorded in The Times when writing about my preparations for the London Marathon. For example, one of the worst hills I have run was at President Bush’s Camp David retreat that he nicknamed Big Bertha. Whenever I have had to run a tough hill since, I have done so saying to myself “this is not Big Bertha” and it helps to get me up. Similarly, when I hit the wall, I imagine on my right shoulder a collection of friends and family who want me to do well and on my left shoulder the kind of people who would like to see me fall flat on my face. It always helps to keep me pressing on.

My triathlon was not long under way when I first called in the “better, faster, stronger” mantra. I had hurt my right calf the day before the race when a car I was in braked hard and sent me flying. It had required physio and massage into the early hours to get me fit to start. We were just minutes into the swim when a fellow competitor accidently punched the injured calf in the mêlée and it went into spasm. For a few moments, I felt a sense of panic and began to wonder how I could get on a bike, let alone run afterwards, without the use of one of my calves. But within seconds, I was ignoring my legs and I carried on through the water, saying to myself “better, faster, stronger” with each stroke. As I entered the final straight of the swim, the calf started to ease, the bike ride was great, the run survivable and although the calf is now a wreck, I feel terrific at having done my first triathlon in well under three hours.

Of course, it may be that I would have done around 2hr 43min anyway. I don’t know. Nor does Tim Smale. But I bumped into two of my team-mates afterwards. Both had done far, far better than they thought they would. Both had been saying to themselves “better, faster, stronger” at various points. If we think it helped, it means it helped.

Indeed, when on Monday night I sought treatment for my calf, the physiotherapist said that the problem was that I had too much mental strength for my physical capability. “Your muscles are very angry with you for making them do what your mind wanted them to,” she said. Mission accomplished, then.

• If you want to make a donation for Campbell’s triathlon appeal, or bid for Lance Armstrong’s Tour de France winning shoe, you can phone 020-7405 0101 or visit www.alastaircampbell.org.uk
  Tim Smale’s website is at www.mindworkslondon.com