I should have guessed by the fact that all the swimmers had brought drink bottles, that this session was for serious swimmers.
It's 8pm on a Monday evening and I have swanned along to Trent Bray Swim School in Kingsland, thinking this will be a relaxing evening activity for me. I have a new pair of swimming togs, the kind you wear if you are a real swimmer who does it for fitness rather than one who farts around in the sea, squealing at the cold. I am even sporting contact lenses, so I can see while I am in the pool. I have borrowed my son's swimming goggles and swim cap too.
But, as fancy as I look, I am no fancy swimmer. It turns out I'm not terribly good on technique or on fitness. It seems I have regressed. By the end of my session I have flippers on and am kicking with a board, like a beginner. I used to hold my own against swimmers at school - when we lived in Australia, what's more. How have things gone so horribly wrong?
I put myself in lane one, that's for the beginners. Trent Bray himself, and another chap, are in lane six. Janet is in lane two. I thought we might perhaps be similar. But oh no. Janet, it turns out, is an ocean swimmer. She just slices her way through the water lap after lap after lap.
I, on the other hand, get to the end of the 25m pool, pant, try to work up some energy and head up again. I have to say the flippers are a revelation. I use them in the beginning for a bit. They are quite heavy on my ankles, so I try it without them and it is like I am treading water, I am going so slowly. A friend of mine who swims regularly says she has her own flippers, hand accessories and a swim board. I get it now.
About 10 minutes in, I realise there is no way I am going to make the full hour. And I think my instructor, Sandra (Trent's mum, lovely woman) is fast coming to that conclusion too. She has been full of excellent advice, things I had heard many times given to my children during their lessons. Keep my head down, keep my kicking small and frequent; the kicking should come from my pelvis and buttocks; think about my posture as I'm swimming, stretching out my arms ahead. We all do that exercise the kids do, where, rather than alternating your arms when swimming freestyle, you use the same arm twice then change to the other arm and do the same thing. I think that is the hardest bit by far.
The most fun part is at the end, with the aforementioned board and flippers. All I have to do is put my head down and kick. I feel like a speedboat, my flippers are like an outboard motor. I'm coming up to breathe only about three or four times. I should have just done this the whole time, I think.
When I get home I can hardly turn the steering wheel as I do the 20-point turn into the driveway, my arms are so tired. It'll get better, I'm told.
It's my birthday and I will be taking the day off, as I do every year. For me, my birthday has to include a variety of things: eating with friends, some kind of gentle exercise, a beach component, ideally a bookshop and a bit of reflection on where I'm at. I encourage everyone to take time out on their birthday.