Just over a year ago I experienced something novel and unwelcome.

I was taking part in a Saturday 5k Parkrun in Co Down. I had come to a steep section of the course and found myself slowing down dramatically. Then, for just a few seconds, I stopped jogging and began walking.

I don’t recall that I made a decision to cease running, it seemed more to be an acceptance from my legs that they just couldn’t do what I was asking of them. As the course flattened out, I gathered myself and resumed a tortuous slow trot.

Later, I reached the finish line where my son, who had completed the course at a faster pace, was waiting for me. I had recorded a time outside of 34 minutes.

I know this is a personal and relative matter. There are many people who would be delighted to run a 5k at all, never mind in 34 minutes. For me, the truth is that there was a point where I could run the distance in 19 minutes. It had never before taken me this amount of time, and I had certainly never previously had to walk. In my 50s, it seemed clear I was showing undeniable signs of deterioration.

My son attempted to console me as I wallowed in self-pity at the end. I found I was struggling to accept what should have been obvious to a man in his 50s. I just can’t do it the way I once could. I became slightly emotional as I wailed that I was now just a ‘fat old man’.

When the tears had dried and the moment of melodrama had passed, I thought a lot about what had happened. I was obviously not the first middle-aged male to become despondent at the signs of physical decline.

It seemed to me that I had reached a crossroads. With the lifestyle I had, the current destination seemed clear. It would be easy to simply accept the signs of ageing and the additional weight I was putting on and settle into a more pedestrian pace of life.

I was even asked by a friend if I wanted to join a walking football club. I went along to watch a match where the men ambled gently across the pitch. But I couldn’t silence the voice in my head which kept saying ‘not yet’.

The choice was clear. Do I want to walk, or do I want to run? Deep inside, I knew that I still wanted to run.

I was aware this would be the harder road because it would involve change. I needed a target to work as motivation. I know that I will never run a 5k in under 20 minutes again, but I was curious to see if I could go under 25 minutes. I had not run that fast in years. The difference between 34 and 25 minutes for 5000m seemed vast at my age. Nonetheless, I told those around me that that was what I wanted to do.

The problem is the gradient becomes much steeper when you are older. In my 20s or 30s, I was still improving physically and the amount of work needed to assist that change was less. Now, I am regressing and the level of activity required to make a minor positive alteration is so much more. Simply put, I have to do a heck of a lot of training for small reward.

I was assisted, as in all things, by my family. My son and brother love to run. My wife joined in the crusade to improve our fitness. We set a programme of midweek training runs and I joined a Pilates class. We also created a Parkrun group and set out to complete a different course each Saturday morning. After the run, we would go for breakfast and share stories and laughs. A key part of ensuring the project had any chance to success was to make it fun.

Over the months, the improvement slowly came. While I was running sub-30 minutes again, going under 25 still seemed a distant aspiration. I felt that a more dramatic change of lifestyle was required.

While I was training, I was aware that my weight was not reducing as I had hoped. It is hard to run 5k fast when you are carrying a spare tyre around your midriff. There is little point spending your mornings pounding the pavements, if you are spending the evenings gorging on crisps and chocolate.

This is difficult for me as I have an addictive relationship with food, and particularly with junk food. From experience, I know there is not much hope in trying to moderate the intake. If I take a little, I will invariably end up taking a lot. The only solution is to cut out sweet stuff entirely. I set a rule that I would eat nothing after dinner.

The runs kept coming and I kept chipping away at my time. It was not all smooth progress and there were plenty of setbacks which left me doubtful I would ever reach the goal.

And then, on Saturday, I did the Newry Parkrun. Halfway through, I sensed I was not tiring as so often before. I managed to maintain my pace and burst through the finish line in 24 minutes and 37 seconds. I had not run a faster 5k in a decade.

Once more, my son was waiting for me at the finish line and, once more, I became emotional.

‘I’m not a fat old man any more,’ I gasped.

‘No Daddy. Now you’re a fast old man.’

When you reach a target there is reflection. After all the hard work, there is the temptation to relax, to fall back to the old ways.

The other path is to keep on running with the support of my family; see how fast I can go and how long I can defy the inevitable process of getting older and slower.

That’s the road for me.