Adidas vs Nike vs Reebok Gym Clothes: Which Brand Actually Wins?

By the Tellar Style Team  |  Activewear Guides  |  Tellar Fashion Hub

I have genuinely worn all three of these brands to death over the years — sometimes literally, in the case of a pair of Nike leggings that gave up entirely during a particularly ambitious squat session and shall never be spoken of again. The big three of gym wear are so ubiquitous that most of us just default to whichever one is on sale or catches our eye, without ever really interrogating whether we're actually making the right choice for how we train. So let's do exactly that.

Adidas, Nike, and Reebok each have genuinely distinct strengths — and real weaknesses. The answer to which one wins depends almost entirely on what you do in the gym and what you want from your kit. Here's the honest breakdown.

Adidas: The Style-First Sportswear Brand

Adidas has spent the last decade repositioning itself as much a fashion brand as a sports brand — and it shows, in both good and bad ways. If you want gym kit that looks impeccable from the moment you put it on and transitions effortlessly into a coffee run or errands afterwards, Adidas is genuinely unmatched. Their collaborations with everyone from Stella McCartney to Ivy Park have cemented their place as the most style-conscious of the three by some distance.

In terms of actual performance, their Adidas Techfit and Aeroready ranges are excellent — particularly for yoga, Pilates, barre, lower-intensity training, and general gym use. The fabrics are soft, flattering, and hold their colour well. Their leggings are consistently rated highly for comfort and aesthetics, with a waistband that stays put and a fabric weight that feels premium.

Where Adidas slightly disappoints is in high-impact technical performance. Their moisture-wicking technology, whilst perfectly competent, doesn't quite match Nike for serious endurance training. And their sports bras, whilst beautiful, can sometimes prioritise looks over genuine support for larger busts during high-impact exercise.

• Best for: Yoga, Pilates, lower-impact training, studio classes, athleisure, style-conscious gym-goers

• Stand-out pieces: Techfit leggings, Aeroready t-shirts, the Adidas by Stella McCartney range for premium performance

• Price point: Mid to premium — leggings typically £40–£80, sports bras £25–£60

Adidas verdict: The most stylish of the three, brilliant for studio and low-to-medium intensity training. If looking good in and out of the gym matters to you, Adidas wins easily.

Nike: The Performance Powerhouse

If Adidas leads on style, Nike leads on performance — and it's not particularly close. Their technical innovation is genuinely impressive: Dri-FIT technology that actually moves sweat away from your body rather than just claiming to, AeroSwift fabrics so light you barely feel them, and a product development pipeline that consistently produces the most technically advanced sportswear on the market. Serious athletes overwhelmingly favour Nike for a reason.

Their leggings are arguably the best in class for high-impact training. The Nike Pro range in particular is a benchmark — compressive without being restrictive, supportive without feeling like you're wearing a tourniquet, and they hold their shape across hundreds of washes in a way that genuinely impresses. Their sports bras are also exceptional for high-impact support, with the Swoosh and Flyknit ranges consistently topping independent review rankings.

Where Nike loses a few points is on comfort for rest days and lower-intensity sessions — some of their performance fabrics are firmer and less "snuggly" than Adidas equivalents. And their sizing has historically been on the smaller side, which can be frustrating. Aesthetically, they lean more utilitarian than fashion-forward, though their recent collections have made real strides on that front.

• Best for: Running, HIIT, CrossFit, cycling, high-intensity training, anyone who sweats heavily and needs proper moisture management

• Stand-out pieces: Nike Pro leggings, Epic Luxe tights, Dri-FIT sports bras, the Zenvy range for yoga

• Price point: Mid to premium — leggings typically £45–£90, sports bras £30–£65

Nike verdict: The best technical performance of the three. If you train hard and need your kit to keep up, Nike is the clear winner.

Reebok: The Underdog Worth Backing

Reebok is the one nobody talks about enough, and I genuinely think they deserve more credit. Historically the brand of choice for aerobics, step classes and the 1990s gym floor — and there's been a nostalgic revival of exactly that aesthetic recently, which has served them well — but their modern performance range is far better than most people realise.

Their strength is strength training, funnily enough. Reebok has long been the brand of choice in CrossFit circles, and their training-specific kit is designed with weightlifting and functional fitness in mind — slightly less compressive than Nike Pro, more flexible through the hip and thigh, and cut to allow for deep squats and lunges without restriction. Their Nano trainers are widely considered the gold standard for cross-training shoes.

Reebok also tends to offer the best value of the three. Their core leggings and training tops frequently come in at a lower price point than equivalent Nike and Adidas pieces without a significant drop in quality. They're also quietly brilliant for inclusive sizing, with a particularly good extended size range. If you want solid, no-nonsense performance kit that won't break the bank, Reebok consistently delivers.

• Best for: Strength training, CrossFit, functional fitness, gym classes, anyone wanting quality at a lower price point

• Stand-out pieces: Workout Ready leggings, Lux leggings, training bras, the CrossFit-specific range

• Price point: Mid — leggings typically £30–£60, sports bras £20–£45

Reebok verdict: Underrated and underpriced. The best of the three for strength training and CrossFit, and the strongest value for money overall.

How Do They Compare on Sustainability?

Increasingly, this matters — and all three brands have made commitments, though the delivery is patchy. Adidas is arguably furthest along, with their partnership with Parley for the Oceans producing genuinely innovative pieces made from recycled ocean plastic. Their commitment to ending virgin polyester use across their range by 2024 was ambitious. Nike has their Move to Zero initiative and uses recycled materials across many lines, but has faced criticism for the pace of progress. Reebok launched a plant-based footwear line and uses recycled content across several apparel ranges, though their overall sustainability profile is less developed than the other two.

If sustainability is your primary concern, none of the three is a perfect answer — but Adidas currently leads the field on material innovation.

What About the Rest of the High Street for Gym Kit?

Worth mentioning: the big three aren't the only game in town, and for many women the best gym kit doesn't carry a three-stripe or swoosh logo at all.

• Sweaty Betty — the British brand that arguably does women's gym wear better than any of the above for studio and yoga-focused training. Their Power leggings are cult classics and the fabric quality is exceptional. Premium price, but genuinely worth it.

• Lululemon — the Canadian brand that's now widely available in the UK and sets the benchmark for luxury gym wear. Their Align leggings have an almost devotional following. Eye-wateringly expensive but the quality is undeniable.

• Gymshark — the British brand that built an empire through social media and genuinely delivers on fit and fashion. Particularly brilliant for sculpting and training styles at an accessible price point.

• H&M — their Move range is seriously underrated for the price. Decent fabrics, good sizing, and styles that borrow liberally from the premium market at a fraction of the cost.

• Tala (independent brand) — a brilliant British sustainable activewear brand founded by Grace Beverley. Their fabrics are made from recycled materials, the fit is excellent across a wide size range, and every piece is designed to work as hard in the gym as it does on the street. A genuinely exciting independent brand that deserves to be on every gym-goer's radar.

• Fabletics (independent brand) — the subscription-model brand co-founded by Kate Hudson has quietly become one of the best value-for-money gym wear options available. Their leggings and sports bras consistently outperform their price point, with a size range running from XS to 4X. A solid independent option if you want to step outside the big three entirely.

Getting the Right Size in Gym Wear — Tellar Makes It Simple

Here's something nobody warns you about when shopping for activewear: sizing is all over the place. A medium in Nike fits completely differently to a medium in Adidas — and Lululemon sizing is famously inconsistent between product lines. When you're buying leggings or a sports bra online, getting the size wrong is particularly frustrating because the fit genuinely affects performance, not just appearance.

Tellar.co.uk is the UK's leading independent sizing tool — completely free, no app or downloads needed — and it matches your exact measurements to the right size across 1,500+ brands instantly. Use the Store Size Lookup tool to find your size in Nike, Adidas, Sweaty Betty, Lululemon, Gymshark and hundreds more before you buy. No guesswork. No returns.

Browse more style advice in the Ultimate Clothing Sizing Guide and explore the Ultimate Guide to Jackets — and if you need help with your full wardrobe beyond the gym, the Tellar Fashion Hub has you covered with honest, unbiased advice from real stylists. Always free. Always independent.

→ Visit Tellar.co.uk

The Verdict: Who Wins?

There genuinely isn't one universal winner — but here's the cheat sheet. Choose Nike if you train hard and performance is your priority. Choose Adidas if you want gym kit that doubles as a genuine outfit and you're doing lower-intensity training. Choose Reebok if you lift weights or do CrossFit and you want the best value for money of the three. And if none of the above feels quite right? Sweaty Betty, Lululemon, Gymshark, and Tala are all producing women's activewear that gives the big three a genuine run for their money — sometimes literally.

Need help finding your size across any of these brands? Use the free Tellar Store Size Lookup tool and explore the full Tellar Fashion Hub for more honest, stylist-led fashion advice.