Horse riding raises the same question as ballet: why is an adult woman taking this up so late in life? This time I solved it by taking my eight-year-old with me, which brought a fresh problem: she’s a natural. She can’t do a rising trot for 50 yards without someone shouting “Brilliant!” at her. I’m not one of those mothers who says that about everything: her nickname is Harper the Quitter. So I felt a bit stupid, like I was trying to bust into her street dance troupe, but on the other hand, there I was, on a horse. And aren’t they lovely?

We went to Allendale riding school on the Isle of Wight, and got to the point quite fast: rising trot is nursery slopes stuff in riding terms but, as exercise, surprisingly strenuous. All its principles are the opposite of a regular workout. You can brace your abs if you feel minded, but nobody ever mentions them. Much more important is to put your weight in your heels, but with your toes pointing upwards, and to keep your legs relaxed.

“Do you go to the gym a lot?”, the instructor asked disapprovingly, and I had to admit that, one way or another, I do. “People who go to the gym often don’t understand how to relax their muscles.” It wasn’t really the gym that did it; I find it very difficult to process instructions aurally and then do it with my body. In an aerobics class, I look like Frankenstein’s monster.

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But the horse gives you a lot of clues: the rising trot is an up-down butt-lift, like a miniature squat in reverse, and it’s quite fast. Your aim is to move in time with the horse; if they’re moving at any speed greater than a plod, your butt has to lift briskly. It probably doesn’t do a huge amount for your arms unless the horse runs away, but it must improve your posture. Forced to sit up so straight, I had to confront my regular slouch; I think I’ve been a little more upright since.

A natural like the Quitter mirrors the horse so smoothly that it doesn’t even look as if she’s moving, more as if she’s being lifted by the beast. Try it yourself, and it turns out it’s much more deliberate, and if you get it wrong, you’re basically landing on the poor animal every time it hits its stride. Unless I was concentrating totally, it was not possible to get this right: and even when I was, it was only at the end of every circuit that I got anywhere close.

Yet it felt more like entrancement than concentration: they really are beautiful creatures, horses. They look great, they smell great. Squinting, you can pretend you’re on a gigantic dog; they have empathy (I think), and if you’re into animals at all, you’ll barely notice any physical exertion in your quest for communion with the horse. I was amazed the next day, when my legs ached in that profoundly self-righteous way, as if I’d done a marathon or a day’s manual labour. I’ve done regular exercise that felt much harder than that, and had nothing like as much after-glow.

What I learned

Trotting burns 460 calories an hour (of yours, I think, not the horse’s).