To me, the gym remains an alien environment. Even though I have been going once a week to see my personal trainer, Ismael, for a few months now, I regard the place itself with no small degree of suspicion.

Ismael has made frequent, fruitless pleas for me to come on my own between our weekly sessions.

“It’s all right for you,”I say, attempting to provide a reason other than “I’m lazy”. I gesture round at the horrible, low-ceilinged but vast hangar-like space with its industrial-looking rows of cross-trainers and bikes, its lumbering grey resistance machines and banks of free weights.

“For me it feels as alien as if I were in outer space.”

The only way I can stand to be there at all is to focus on Ismael himself and the exercises. Luckily, he is a nice chap with a nice face. His manner is absolutely the antithesis of the other “PTs” — Personal Trainers — who apparently inhabit the gym on a permanent basis and strut about in very tight tops to show off their bulging muscles. Ismael speaks very quietly, and is not gung-ho; there are no shouted instructions to “Go for the burn!”

Last time, I spotted that he didn’t change the weights on one of my usual machines. You enter its hulking grey embrace, and sit at the heart of it then attempt to push its huge weighted arms away from you. I feel like Ripley in Aliens when she dons the outsize robotic suit to fight the Alien Queen.

Usually, he sets the weights at 12.5kg each side (Feeble, I know, but I can barely move it at that). Today, it’s already on 15kg each side but he leaves the weights as they are.

“But I can’t do that,” I tell him, as ever Queen of Positive Thinking.

“Yes, you can. I have faith in you.”

Ismael has faith in me because he’s a nice person. There is no factual foundation whatsoever for his faith in me, other than that I turn up reliably each week. My favourite phrases at the gym are:

“It’s too heavy.” “It’s too hard.”

“I can’t do it.” “This feels heavier than last week.”

And, a new one this week: “Is the machine locked? It’s not moving.”

In contrast to the bulging biceps brigade, Ismael wears comically loose clothing — so loose he looks as if he’s just stepped into a tent that hasn’t yet had its guy-ropes secured… But the baggy clothes are his choice for a reason. Ismael is a very, very devout Muslim.

Because I am so nosy, and also because it often buys me a few moments respite from the horrors of exercise, I frequently ask him questions about his faith.

After all, it is hard to think of any other circumstances in which a not-very-observant Jewish woman would have weekly tête-à-têtes with a very observant Muslim man and I feel I should make the most of it.

Slowly, together, we will establish the Jewish-Muslim Peace Accord, which will lead to world peace and an end to hatred everywhere.

This is the kind of thing I think about when I’m at the gym instead of steeling myself with go-girl gym talk such as “Fire up your glutes!” and “Engage your quads!”

But already there’s a glitch. When Ismael tells me that he used to be a DJ but now never listens to secular music because it’s haram — forbidden — I feel my hackles rising.

How does it benefit Allah, or the World, if Ismael shuns Vivaldi’s Four Seasons, say? It’s not gangsta rap, is it?

Yes, it’s secular but surely good music is spiritual, uplifting, inspirational? At the moment, I keep returning to some particular piano music by Erik Satie (Gnossiennes 1 & 3). I can’t put my finger on exactly why it resonates so with me, I only know that when I hear it I feel better, soothed, at peace.

How can that be bad? I know I’m not a properly good person — too selfish, too greedy, too lazy, just for starters — but love of music must be one of my most harmless attributes.

I find myself speculating about Ismael’s shape because the fact that you really can’t tell what it is, is intriguing. The bulging biceps guys trigger absolutely zero interest in me. Their wares are out on display — there’s nothing to think about. It’s not that I’m attracted to Ismael — I’m intrigued only because I can’t see. It’s curiosity, not lust.

Still, it sets me thinking about rules on covering up, both for Muslims and Orthodox Jews. Maybe the original intention was not about modesty at all? Maybe it’s a way of keeping the sexes interested in each other? Of preserving the mystique. After all, the great passion-killer is usually familiarity not concealment.

Maybe instead of covering up in the public realm and removing the sheitl or hijab at home, it should be the other way round so that relationships would be constantly refreshed by that shimmering frisson of anticipation? No more sauntering about at home in a T-shirt and pants for me; I’m off to buy a floor-length kaftan…

Zelda Leon is half-Jewish by birth then did half a conversion course as an adult (half-measures in all things….) to affirm her Jewish status before a Rabbinical Board. She is a member of a Reform synagogue. Zelda Leon is a pseudonym.