Best Buys: Under Armour Gym Clothes — Are They Actually Worth It?

Under Armour gym clothes are worth it — but only if you know exactly which pieces to buy and which to skip. The brand has a genuinely impressive performance pedigree, but not everything in the range delivers equally, and in a market where Lululemon, Sweaty Betty, and Gymshark are all competing hard for the same customer, you need to know where Under Armour genuinely wins before you spend your money.

I'll be upfront: I came to Under Armour late. For years I was a loyal Sweaty Betty devotee — great leggings, lovely branding, and you felt vaguely like a person who had their life together just by putting them on. Then a friend lent me a pair of Under Armour HeatGear leggings for a spin class I'd under-packed for, and honestly? I was converted on the spot. The compression was different — more purposeful, less decorative. And they didn't roll down once during an entire session, which if you've experienced the slow, undignified waistband descent mid-burpee, you'll understand is not a small thing.

So let's break down the best Under Armour buys properly — what the range does brilliantly, where it falls short, and how it stacks up against the competition.

What Under Armour Actually Does Better Than Most

Under Armour built its reputation on performance fabric technology, and in certain categories that foundation still shows. Their proprietary fabric technologies are genuinely well-engineered:

HeatGear — designed to wick sweat and keep you cool during high-intensity training. It works. The fabric pulls moisture away from skin quickly and dries fast, which matters enormously in a long or sweaty session.
ColdGear — a dual-layer fabric that traps warmth close to the body whilst wicking sweat outward. For outdoor training in British winters, this technology is genuinely useful.
StormGear — a water-resistant treatment on outerwear that repels light rain without sacrificing breathability. Useful for running outdoors or training in unpredictable weather.

The brand also tends to be better than average on compression — their tighter-fit pieces provide genuine muscular support rather than just aesthetic compression, which makes a real difference during weight training or high-impact cardio.

The Best Buys: Pieces Worth Your Money

Under Armour HeatGear Leggings are the hero product and the starting point for any Under Armour wardrobe. The mid-rise and high-rise options both deliver solid compression, a secure waistband, and sweat-wicking performance that holds up through intense sessions. They're not the most stylish legging on the market — the design is functional rather than fashion-forward — but if you're training seriously rather than gymfluencing, that's arguably a point in their favour. The four-way stretch fabric moves with you without bagging at the knee, which cheaper alternatives often fail at.

Under Armour Meridian Leggings are the slightly more lifestyle-oriented option from the range — a buttery-soft fabric that sits somewhere between gym wear and everyday wear. If you want something that transitions from a yoga class to brunch without screaming "I've been exercising," these are the ones. The waistband is particularly good — wide, flat, and genuinely secure.

Under Armour HeatGear Compression Short-Sleeve Top is one of the best performance base layers available at the price point. It fits close to the body without feeling restrictive, wicks sweat effectively, and crucially doesn't go see-through under studio lighting — a problem I've encountered with cheaper alternatives that I'd rather not relive.

Under Armour Seamless Sports Bra — the seamless construction reduces chafing during long sessions, and the medium-impact support is genuinely reliable for most gym training (though for running or HIIT, you may want to size up or go higher impact). The ribbed fabric has a premium feel and washes well without losing its shape.

Under Armour Qualifier Running Jacket is the outdoor layer I'd recommend unhesitatingly. Lightweight, packable, with StormGear water resistance and reflective detailing for early morning or evening runs. It doesn't add bulk, moves freely with your stride, and looks sharp enough that you won't feel awkward wearing it beyond the gym.

Under Armour HOVR Shoes — worth a specific mention because the footwear range has significantly improved. The HOVR Sonic and HOVR Phantom lines offer genuine cushioning and energy return, and they've been well reviewed by running communities for comfort over longer distances. If you've always thought of Under Armour as primarily a clothing brand, the trainers deserve a second look.

Where Under Armour Falls Short

In the interest of honesty — because I think you deserve that more than a breathless brand endorsement — there are a few areas where Under Armour loses ground to competitors.

Aesthetics. Let's be blunt: if style is your primary driver, Lululemon and Sweaty Betty are more considered in their design. Under Armour's colour palettes tend toward the functional (a lot of black, grey, and navy) and the branding is prominent in a way that feels slightly dated. It's improving, but it's not yet a brand you'd choose purely for how it looks.

Sizing consistency. This is a genuine frustration. Their sizing runs quite small in some lines and true-to-size in others, which makes online ordering feel like a lottery. I've ordered the same size in two different Under Armour legging styles and had notably different fits — worth keeping in mind.

Yoga and low-impact wear. For hot yoga, Pilates, or any practice requiring a softer hand-feel and more fluid movement, the compression-heavy Under Armour fabrics can feel a little stiff. This is where Lululemon's Align range or Sweaty Betty's Zero Gravity leggings would be a better call.

How It Compares: Under Armour vs The Competition

Under Armour vs Lululemon — Lululemon wins on fabric feel, design, and the overall luxury-of-gym-wear experience. Under Armour wins on price and technical performance in high-intensity training. If you're a serious athlete on a budget, Under Armour. If you want gym wear that doubles as a lifestyle brand and price is less of a concern, Lululemon.

Under Armour vs Sweaty Betty — Sweaty Betty has better pattern design and a more considered aesthetic, and their Power leggings are arguably the best squat-proof legging on the UK market. Under Armour's compression and moisture management is more technically rigorous for running and high-intensity training. Both are excellent; it genuinely depends on your workout.

Under Armour vs Gymshark — Gymshark has the edge on Instagram-driven aesthetics and trend-responsive design. Under Armour has the edge on longevity, technical fabric, and performance credibility. Gymshark feels more of-the-moment; Under Armour feels more durable as a long-term investment.

Two Independent Activewear Brands Worth Knowing

Tala is the sustainable activewear brand that's been quietly taking over UK gym changing rooms for the past few years. Founded by Grace Beverley, the fabrics are made from recycled materials, the price point is competitive, and the squat-proof performance of their leggings has been widely praised. If sustainability matters to you alongside performance, Tala deserves a serious look.

Girlfriend Collective is a US-born brand that's gained a strong UK following for its inclusive sizing, beautiful muted colour palette, and commitment to recycled fabrics. Their compressive leggings in particular are excellent — flattering, supportive, and made to last. A genuinely brilliant alternative to the mainstream activewear brands.

The Verdict: What Should You Actually Buy?

If you're building a gym kit and want reliable, technically capable pieces that will genuinely perform across high-intensity training, running, and strength work — Under Armour is an excellent choice at a fairer price than Lululemon. Start with the HeatGear leggings, add a seamless sports bra and a close-fit top, and you have a kit that will carry you through almost any session.

If your training is primarily yoga, Pilates, or lower-impact activity — look elsewhere. Under Armour isn't built for that world, and there are better options at similar prices.

And whatever you buy — always check the fit properly before committing. Under Armour's sizing inconsistency is real, and the difference between a legging that fits perfectly and one that's a size out is the difference between a great training session and an irritating one.

Get Your Exact Size in Under Armour — and Every Other Activewear Brand

One of the most common complaints about activewear — Under Armour included — is that sizing is completely inconsistent across different lines. A medium in HeatGear fits differently to a medium in Meridian, which fits differently again to a medium in their outdoor running range.

Tellar.co.uk is the UK's leading independent sizing tool — matching your exact measurements to over 1,500 brands instantly, including all the major activewear brands. Measure once using your bust, waist, and hips, and Tellar tells you your precise size across every brand you want to shop. No more guessing, no more returns.

Use the Store Size Lookup Tool to check your exact fit in Under Armour, Lululemon, Sweaty Betty, Gymshark and more — completely free, no app needed, works straight from your browser.

And explore the Tellar Fashion Hub for honest, unbiased style advice across every category — from activewear to occasion dressing. Our stylists have no brand allegiances and no hidden agendas. Just real advice, always free.