I work just outside Leeds city centre, to the south of the river Aire, which splits the city like a miniature Thames. Running alongside the Aire, to the west is the Leeds-Liverpool canal.

At exactly midday, I grab my bag and head to the work changing room (I’m very lucky to be in a modern office, with plenty of showers and a dedicated drying room for wet kit). I hurriedly get changed into my running gear. I’ve been in an air-conditioned open-plan space for the last few hours. I have a limited view out of the window. I barely know what the weather is doing, let alone how warm it is out. I’m planning on running quickly, so accept I’ll probably be uncomfortably cold in a light base layer and shorts for a few minutes, but know I’ll still be sweating by the time I finish.

Zipping my security pass into the little pocket on my shorts, I step out of the carefully controlled work environment. In to the real world. I stand, looking at the sky through a letter box space between buildings… frustrated by waiting for my GPS watch to find signal with its restricted view. I want to escape as soon as I can.

Beep. I’m off. Less than 4 minutes, and under a kilometre later, I’m on the canal bank, treading the old towpath. I know this because said new GPS watch vibrates every kilometre. I reach the first railway bridge as it vibrates for the first time. Within the first few kilometres of canal, there are many crossings. For the most part they are the result of newer forms of transport requiring their own direct route into the city. I’ve crossed over many of them, unaware that the canal is directly below me. As I run though, the roads and railways don’t exist. They are simply bridges. My world is a long stretch of path, next to the canal. I run through (or more accurately, below as the canal feels sunken into the surroundings) places with names, but they don’t matter. I’m just on the canal. I’m running. I’m not at work.

For a short while I am colder than I was when I started. The cool, low air clings at me. I increase my pace slightly. My stomach rumbles. I forgot to eat a snack half an hour or go, and I’m ready to eat lunch. Were I out for longer, I would be concerned, but I’ll be back where I started within 20 minutes. My watch vibrates again.

I’m trying to carefully manage my pace. I want to run a negative split – to do the second half of my run quicker than the first. My feet are tapping a rapid rhythm. I feel loose, light, comfortable. I start to leave the city behind as I duck below the inner ring road. It is by no means countryside, but the buildings are lower, and office blocks are replaced by light industrial units. There are a few old mill buildings still tucked in there, most looking decrepit but still somehow stately in their presence. I’m overtaking other runners – out in ones and twos… the odd bigger group. Winters used to be my time along the canal, but now it is almost as busy as the summer. It’s nice to see, and there are now lots of familiar faces. We all have our routines – if I leave my run until a little later, I see a completely different group of people.

I reach the turnaround point – a bridge with a sign. In upside down text it reads “the remains of a wooden icebreaker lay here”. Reflected in the water, it can be read normally. My velocity is reflected at the same point. I touch the wall of the bridge and retrace my steps, consciously quickening my pace. For a few seconds I try to find a new balance between my breathing and footsteps. I stop thinking about it, and it comes. There are two or three locks on this stretch of canal. They were uphill bursts on the way out, they are now downhill sprints. I let myself go and force my legs to keep up.

I’m settled into my favourite pace. I know it isn’t completely sustainable, but I also know that I still have more to give. I could kick if I wanted to. I hold off. The Leeds skyline fills my view. Tower blocks are growing larger. Granary Wharf is getting closer. I push a little harder. My footsteps are still light, my form is still tight, my lungs are beginning to burn. I push harder again. I have a few hundred metres left, I feel myself faltering, I run faster. My last few steps are long and slow as I slap my feet down through the gate at the end of the towpath. I press stop on my watch, and slow down to a jog. I fill my lungs with cold air. I empty them. I refill them and increase my speed slightly, snaking my path around buildings full of desk-bound workers, ready to return to the fray.