My class numbers almost dropped by half over the week’s heatwave. So much for ‘hot yoga’ then! But well done those that came and I hope no ill effects – do let me know.

It prompted many of you to ask about ‘hot yoga’ … basically what is it and why do it?

The concept emerged in America around 20 years ago, developed from hatha yoga by Bikram Choudhury. It is practiced in a room at 40 degrees with 40% humidity. The class typically runs 90 minutes and is always the same 26 postures with 2 different breathing techniques chosen by Mr Choudhury.

It has grown in popularity in this country more recently, and there are now different styles (and temperatures) on offer. This extract explaining its benefits is taken from the ‘hot power yoga’ website where yoga flow sequences are taught in lower temperatures of around 30-34 degrees (similar to those we experienced recently) but often in humid conditions.

“There are a number of reasons: Firstly our skin is the largest organ of our body. With the heat, you will sweat and this releases toxins from the body. The heat and sweat therefore helps you detoxify. The heat also warms the body and encourages muscle suppleness, joint mobility and flexibility. This means you can have a deeper yoga practice, but also the chance of injury is reduced.

We also enjoy the challenge the heat provides - sweating and letting-go feels great, and at the end of a Hot Power Yoga practice you will feel physically, mentally and emotionally cleansed. This is why Hot Power Yoga is such a great antidote to modern London life.”

In my view, it is of concern that such nonsense is written with no medical  or research evidence to back up their claims, for instance that sweating profusely benefits the body by releasing toxins, or that there is less of a risk of injury.

If you carry out an internet search on hot/Bikram yoga, for every article extolling its virtues, you’ll see another warning of risks such as over-stretching, wear and tear of ligaments and tendons (which unlike muscles do not benefit from being heated up), and heart problems.

Yoga has been around a long time, and fashions will come and go. No doubt, someone will one day rename slow or gentle hatha yoga as ‘cool yoga’ … or ‘chilled out yoga’. And market it as new as sliced bread.

Ultimately, it’s your choice: If you are young, fit and not carrying excess weight then hot yoga may suit you very well. But, if like me, you struggled in the last week to keep cool, let alone do a dozen salutes to the sun, then perhaps it’s not worth the risk.

And, if you think bunching together in a crowded studio with a lot of hot and sweaty people a daft idea, how about this for craziness … beer yoga