The school field is an ocean of bodies, bobbing and stretching. Weathered sinewy adults and bouncy excited children. Is this what 750 people look like? I’m as nervous as they are. More nervous. I’m the reason they are all here. The sun is shining and it is the Saturday before the London Marathon in April 2007.

Two years earlier, the High Street was closed and we were all standing in the middle of the road. My tummy was fluttering and my limbs were chilly. “I’ll start near the back of the pack as I’ve never done this before.” I told myself that no-one was looking at me in that crowd. Me, in my unfashionably baggy shorts – all the other ladies seemed to be wearing lycra. The smell all around of deep heat had cleared my nose and was now nauseating me. We started to squash forward in anticipation even thought nothing had happened. And then muffled words spewed out of a megaphone and we were off.

The ocean of people is lapping round me and asking me questions “Where’s the start?” “When’s the briefing?” I’m drowning! I seem to be the only fluorescent bib on the field and they are closing in on me. And my marshals, nervous too, are phoning me in relays to tell me they are ready out on the course. I glance at my watch and scan my plan, pages going crinkly in my sweaty hand. I need to get out to the start area. The start is prepared and here comes the flood of bodies, warmed up, briefed and raring to go.

“Start slow,” was my mantra. And I did. Before long there was just me and a couple of old biddies wearing running club vests and they were having a good chat about their holidays. A high-vis marshal at the first big junction stopped the traffic for me “Well done love, keep going and you’ll get a personal best today!”

“Three, two, one, go” and the 10k runners surge past in a long stream and the 4k runners drift up to the line. Keen teenagers, a sea of blue race t-shirts, in the front row; unfit mums and dads, running for the cause, linger at the back.

The lady in front of me had flapping laces; she stopped to tie them and I overtook her. After about 8k I felt a bit wobbly and walked a few paces but that felt worse. The marshals all smiled and cheered me on. They knew I was one of the last and I needed encouraging. And they knew they had nearly finished their jobs and could go home soon.

I feel relief as the starts pass without incident or drama. But in less than 20 minutes the 4k runners will be finishing and I need to make sure it’s all set up. The funnel of red and white tape leads the runners past computer timing to medals, a bonanza of goody bags and a forest of bananas.  Another flight of marshals is standing by ready for the tidal wave of finishers. Meanwhile, the younger children’s fun runs are rolling along on the running track. I can hear the PA system echoing around the field as the little athletes collect their prizes.

My final 500m felt good although I had to push my way past early finishers walking home. I felt tearfully euphoric as a finishing marshal urged me across the line before the clock ticked on another minute. Someone thrust a bottle of sports drink in my hand and I downed it in one.

It’s high tide on the school field again. My ocean of faces is smiling now. They are finding their friends and family, comparing their times and telling their stories. Waves of clapping are crashing all around me and I’m beginning to rise on the positive vibes. The marshals are drifting back, and I’m hugged and hand-shaken. They tell tales of grateful runners and a morning well spent. They bring back the luminous flotsam of signs and bibs, netted with red and white tape.

I’d done my first 10k. I hadn’t trained for it – I didn’t even know about training. My result was a triumph of determination over preparation. It hurt for 9.5k but I wanted to do another one. I also knew that the marshals had done more than show me the way – they had got me round.

My marshal’s pile of flotsam grows as the runners and helpers disappear – quickly like the tide ebbing over a flat sandy beach. Six months of risk assessments and planning meetings, e-mails and talks with the aristocratic landowner to set this up: and the races were all over in a splash. It’s just two years since I’d run my first race, and today I’d organised one – a 10k, a 4k and a fun run. I’d brought together a team of 75 to make it work – and 750 people had gone home having had a good time. I was running on top of the world.