A Glasgow-based activewear brand has been named the UK鈥檚 fastest-growing private company. The DFYNE business sells gym attire for men and women and has enjoyed 517 per cent average annual growth in the last three years, according to the latest Sunday Times 100 rankings. The firm generated revenues of 拢66.8 million in the 12 months to May. Three Scottish companies made it into the 2025 listing – the other two being Ayrshire-based heating and insulation installer Green Home Systems, in 39th place, and Edinburgh-headquartered restaurant chain Maki & Ramen, which grabbed 78th spot. DFYNE employs almost 130 people at its headquarters in Glasgow, and it is the third business that its founder, Oscar Ryndziewicz, has launched. He said: 鈥淭here is always a bit of luck involved and anyone who has done well who says otherwise is not really telling the truth. But if you don鈥檛 try you are never going to get lucky.鈥 Health and fitness brands have emerged as being among Britain’s fastest-growing private companies as entrepreneurs across the country tap into blossoming lifestyle trends. In the number two spot UK-wide is Healf, a London-based retailer selling health products from vitamins and minerals to fitness watches and sleep masks. The company鈥檚 sales increased more than fivefold on average over the past three years, with it making 拢40m in the latest year, the research found. Other firms included in the top 20 that have tapped into the burgeoning demand for wellness include Ancient + Brave, a brand selling collagen and dietary supplements, and Rheal, a Sunderland-based superfoods retailer. Sportswear brand Montirex and health-focused meal delivery firm Simmer Eats also clinched spots in the annual list. The publication compiled its fourth annual list by examining sales growth figures across private companies – excluding those selling their own technology, which feature in a separate table. The listing is sponsored by Barclays Private Bank and supported by S&W, the professional services firm, Oracle NetSuite and Singer Capital Markets. Elsewhere, Nala鈥檚 Baby, which sells skincare and haircare products for children and babies, was number ten in the rankings, having enjoyed sales growth of 175 per cent over the past three years. The brand was founded by Casyo Johnson – otherwise known as Krept, one half of UK rap duo Krept & Konan – with co-parent Sasha Ellese in 2022. The research also found that, of the 100 companies featured in the rankings, more than a third (36) are based in London, with the rest spread throughout the UK. There were 28 businesses included this year that have female founders or co-founders, including fashion brand Odd Muse, in fourth place, and jewellery business D.Louise, in ninth. About half of the companies on the list trade internationally, according to the research. Mo Syed, head of Barclays Private Bank and Wealth Management UK, said: 鈥淭his prestigious ranking celebrates the innovation, ambition and resilience of Britain鈥檚 entrepreneurs – qualities that we at Barclays Private Bank are privileged to support. 鈥淎s these dynamic businesses scale and evolve, we鈥檙e committed to being the trusted partner for their strategic wealth, investment and succession planning.鈥