The only exception to gulping, says Bean, is if you’re slightly dehydrated at the start of class and need to get fluid on board quickly. “Those three to four gulps - around 150ml - will be absorbed reasonably fast if your body needs it,” she says, who advises using the good old ‘toilet test’ to check that your urine is an optimal pale, straw colour and no darker.

Experts also agree that pure water really is all you need for a sweat session running under 90 minutes. Luke Worthington, trainer at FIIT, suggests that topping up on electrolytes, which can be found in bananas and coconut water, could also help boost hydration, but insists that supplementing with Branch Chain Amino Acids (BCAAs) is a waste of money. As is investing in a pricey water bottle. “Choose whichever refillable water bottle is most comfortable for you,” he says.

So the next time you’re assembling your gym bag, maybe give that water bottle the attention it deserves.

A step-by-step guide to workout hydration…

1. Don’t drink the moment you step into class

“Ask yourself if you really are thirsty yet, otherwise hold off,” advises Anita Bean. “You shouldn’t force yourself to drink.”

2. However, if you think you might be slightly dehydrated, drink little and often

“Take three to four generous sips - around 150ml - every 15 minutes to get your hydration levels back on track,” says Anita.

3. Drink within the first 30 minutes of a session

“If you’re working out for an hour or longer you should start sipping within the first half an hour,” recommends Anita. “It takes approximately 15 to 30 minutes for the water to reach your cells.”

4. If you don’t tend to sweat or get thirsty, don’t go entirely without

“Try and take in even a small amount of water every 20 minutes or so,” says Andy Vincent.

5. Don’t drink too much towards the end of your workout

“It takes 45 minutes to fully rehydrate,” notes Neville Kenwright. So there’s no need to go overboard close to cool down.

Three water bottles that tick the PTs’ boxes…

Bobble

How to drink water during a workout