When the coronavirus lockdown was announced, Irina Allport thought her business as a personal trainer would never recover.

But so successful has her transition to online training been, with her client base expanding to the US and even New Zealand, that the announcement of gyms reopening next week in England – news she spent months longing to hear – is almost irrelevant to her.

“I’m more successful as an online personal trainer than when I spent hours criss-crossing London, visiting offices and gyms,” she said. “I now teach people across the UK and the world – I have clients in New Zealand and New York.

“Time differences allowing, I can teach clients whenever they have a slot in their diary – which means I’m not limited to the old ‘before work, lunchtime, after work’ slot,” she said. “Not only do I not have any overheads but it’s quicker and more convenient for clients too: working and training from home means they don’t have to do the whole time-consuming routine of changing clothes and showering to get office-ready again after a workout.”

Allport moved her business online as soon as the pandemic hit. Initially she struggled. “There were so many big names posting free workouts online,” she said. “Also, at the start of lockdown people either couldn’t, or understandably wouldn’t, spend money on extras like personal training.”

But gradually, Allport said, her online business took off. Thanks to a combination of referrals, the return of old clients and relentless online marketing, she now sees more people than before lockdown.

Allport even has clients who have continued their training on holiday. “Recently, a client went to Europe for a week and we just continued our sessions,” she said. “When you’re teaching online, geography is irrelevant. It’s amazing: what seemed in March like the end of my career as a personal trainer has ended up being probably the best thing that could have happened to it.”

Sarah Newman, a specialist trainer working predominantly with cancer patients, said online personal training sessions had transformed opportunities for her vulnerable clients. “With no experience of teaching virtually, I moved my sessions online in a single weekend,” she said. “I had to be creative and jump on this as an opportunity.

“Even clients who might have been reluctant to do anything online before, because they’re not tech-savvy, quickly realised that online training has almost more positives than negatives.

“When clients do virtual training, they can do it whenever suits them across the day. They also have a level of privacy they really like and geography isn’t an issue – I have new clients across the UK. My business has grown as a direct result of lockdown.”

Macmillan Cancer Support has also realised the potential for virtual fitness training. Two weeks after lockdown began, the charity launched a free pilot scheme for people with confirmed or suspected cancer called SafeFit, in collaboration with organisations including University Hospital Southampton NHS foundation trust, the Royal College of Anaesthetists and the CanRehab Trust.

June Davis, an adviser for allied health professionals at Macmillan Cancer Support, said: “Demand has been high. The aim now is to offer it as a UK-wide service to support people preparing for and going through cancer treatment while following Covid-19 government guidelines.”

Personal trainers who taught from gyms have struggled in the months of enforced closure, and are scrambling to find new business models in case clients do not return next week. Not all say the move to online sessions has been successful.

Bryce Dunn works for Cre8 Fitness, a small gym in the centre of London that takes just six clients at a time for personal training. “I don’t know if the gym will survive because it relies on clients returning to work in large enough numbers,” he said.

“I’m offering online training but a lot of people’s motivation has fallen away without the routine of coming to the gym and the impetus we give clients. I’m trying to think of alternatives but it’s not easy to rebuild an entire business model.”

Evgeny Loskutnikov, who trained clients at a gym in Wrexham before the pandemic hit, is also reinventing his business model. “I couldn’t be as present for my clients when I tried training them online, so I had to stop entirely,” said Loskutnikov, who spent the lockdown working at a chicken farm.

As restrictions eased, however, a new business model suggested itself to him. “A lot of old clients began asking if I could come to their houses – with all the PPE – for training,” he said. “Clients tell me that even though it might seem like a luxury, they need the motivation of personal training for their mental health. Lockdown has affected a lot of them quite badly.”

He added: “They tell me they need the structure and goals that training gives them, to get them back on track.”