“Hit them like you mean it – they can take it!” is probably the last thing I thought I’d ever hear booming across a library.

But every Wednesday in Barking Learning Centre’s conference room, kickboxer Sarah Robertson runs BoxFit Ladies – a free class for women aged 18 and over.

“We work with all abilities – most of the women who come here say this is the first time they’ve done boxing,” she said. “And for some it’s the first time they’ve done sports in 20 years.

“We don’t push people unless they want to be pushed but it’s a good work-out that increases flexibility and fitness.”

The exercise certainly started off light, with stretches and casual conversation – but the ladies were soon performing rapid punching circuits after step-by-step technique tuition on stance, movement and jabbing “like a woman”.

And even the oldest member of the group, Claire White, 54, from the Gascoigne Estate, was up for a challenge.

“My daughter brought me here three or four weeks ago and it’s brilliant exercise,” she said. “It’s quite hard but it’s good fun and it’s a girly, friendly environment.

“Everyone’s welcome, just take that first step and enjoy it – you will like it.”

The class was launched at the learning centre in June, after securing £21,000 of Health Lottery funding that will keep it free until 2017.

And there’s also a supervised colouring-in area for children whose mums attend.

Krystal Oakley, 24, who volunteers to help run the class, says this helps open the class up to women who wouldn’t normally attend as it takes the burden of childcare fees away.

“It gives more leeway to get more people to come,” she said. “We also talk about healthy eating and give them advice on what they can and can’t eat.

“And those that do come gain confidence and learn how to participate in a healthy lifestyle.

“And that makes me feel like I’m doing a good job.”

All women are welcome at the class, which runs every Wednesday from 6pm to 8pm.