On a dark autumn evening, first-timers arriving for self-defence classes at Urban Fit and Fearless are asked if they have had any past traumas before they start training.
After a series of high-profile murders of women in London in recent months, the number of young female participants joining the class is high.
One of them, Laura Thompson, a 29-year-old account manager, told AFP: "I think a lot of women at the moment, especially living in London, are pretty shaken up.
"I know a lot of friends that openly talk about how worried they are or how they don't feel safe.
"It's definitely in the back of my mind and I think something like this is definitely going to help."
The disappearance of Sarah Everard, a 33-year-old marketing executive, as she walked home in south London in March sparked renewed anger and concern about women's safety.
A serving Metropolitan Police officer later admitted her kidnap, rape and murder, and was sentenced to life imprisonment.
Everard's murder came nearly a year after two sisters, Bibaa Henry and Nicole Smallman, were stabbed to death by a man in a Satanic-inspired attack in a northwest London park.
In September, a schoolteacher, Sabina Nessa, was found dead in another park, in the southwest of the British capital. A man has since been charged with her murder.
- 'Take back control' -
All three high-profile killings have fuelled calls to combat male violence against women, and spurred demands for better safety for women and girls in public spaces.
Hannah Feiner, a 31-year-old government lobbyist, said she had decided to take the self-defence classes as a direct reaction to Everard's murder.
"I feel really unsafe in London at the moment. I felt Sarah Everard's death really strongly this year," she said.
"I've grown up in London and it's the first time I've felt unsafe on the streets. I felt like I needed to do something about it -- take back control."
Two-thirds of the mixed class of 26 are women. Dressed in lycra and tracksuits, they could be meeting for boxing, yoga or any other exercise class.
But implied throughout the training is the possibility that the techniques the students are learning could one day save their lives.
"Put your weight on me, grab my throat," male instructor Patrice Bonnafoux says to a volunteer as he demonstrates how to roll out of being pinned on the ground by trapping an attacker's leg and using their weight against them.
"When you pin someone to the ground it's easy for women to see the worst case scenario," Bonnafoux explained later. "I don't want to trigger. I want the class to stay fun."
It was common to see an increase in students joining classes following violent events, he added.
Bonnafoux was first exposed to the Israeli fighting system Krav Maga that he now teaches during commando training in the French army.
Over the decades, he has seen the number of women learning the defence system rise dramatically.
"Women's interest in self-defence has been strong for a very long time. And I would say anyone who's surprised by that hasn't been paying attention."
- If only? -
Increasingly, the mothers of young teenaged daughters were getting in touch to enquire about classes, said Bonnafoux -- a trend he attributed to fears following Everard's murder.
"I think the fact that the guy was a cop shocked a number of people," he said.
Mothers felt "if we can't even trust the cops then we need to do something", he added.
Among the students at his Wednesday night class was one 16-year-old female student who had brought herself to the self-defence sessions on her own initiative.
Another instructor, Di Lebowitz, runs a separate, women-only self-defence class in Vauxhall, also in south London, said she had seen a "big rise" in enquiries.
"Since this whole tragedy, there's definitely been a lot more students or prospective students coming to want to learn how to defend themselves," she said.
Lebowitz, who has been an instructor for five years, took up Krav Maga while travelling in Cambodia to protect herself.
The former school teacher said she and her students felt Sabina Nessa's death particularly keenly.
"I get incredibly sad when these sorts of things happen. There is this niggling feeling," she said.
"Specifically with the Sabina Nessa case, I just keep replaying in my mind, if she had come to a few lessons if she knew how to kick, if she knew how to push... would that have changed anything?" Lebowitz added.