The 2026 THETA sizing guide works on one core principle: tops are cut fitted across the chest and relaxed on the stomach, and shorts use a fitness-racing-specific fit. Take your normal size for a performance fit, size up one for a looser feel, and use the fitted-chest, relaxed-stomach cut to judge how a top will sit rather than a slim or baggy label.
- THETA tops are precision cut per size and built fitted across the chest, relaxed on the stomach.
- Shorts use a fitness-racing-specific fit that sits closer than loose run shorts so they stay put through lunges.
- Women's pieces are engineered by THETA's female athletes for a women's fit, not a shrunk-down unisex cut.
How does THETA cut its tops?
Most people assume a performance top has to be either slim or baggy, and that you pick your side. That is the misconception worth clearing first. Every THETA top follows a single design language instead: fitted across the chest and relaxed over the stomach, with the Race Team v2 tee precision cut per size rather than simply scaled up and down. The fitted chest keeps the top close so it does not flap on the eight runs or catch on the sled harness. The relaxed stomach stops the fabric clinging when you breathe hard or hinge at the hips. So if you like a true performance fit, take your normal size; if you prefer more room through the body, size up one and accept a slightly looser chest. The fabric is ultra-light and does not cling when soaked, so it never needs to be worn tight to perform.
How should the shorts and bottoms fit?
Start with what the shorts are trying to solve. THETA shorts use a fitness-racing-specific fit, which sits closer than a standard loose run short so they stay put through sandbag lunges and burpee broad jumps. The Tech Short v2 pairs that fit with durable polyester and elastane 4-way stretch, so a closer cut never restricts a deep lunge. Half tights are a different fit again, sitting close by design with a sweat-wicking liner and multiple pockets, so take your normal size for a supportive feel. What is easy to miss is that the closer race short is intentional: loose shorts lose their shape under intensity, while a race fit keeps a clean silhouette when you are fatigued and wet.
| Piece | Fit character | Sizing guidance |
|---|---|---|
| Tech / Race tops | Fitted chest, relaxed stomach | Normal size; size up for looser body |
| Tech Short v2 | Fitness-racing-specific, close | Normal size |
| Half Tight | Close, supportive | Normal size |
| Women's race pieces | Women's engineered fit | Normal size; women's-specific cut |
How does women's sizing differ?
The common assumption is that women's kit is just men's kit made smaller, and that is exactly what the women's range is not. It is engineered by THETA's female athletes rather than shrunk from a unisex pattern, so the fit reflects a women's shape. The Women's Race Singlet re-shapes the same record-setting race system for a women's fit, staying ultra-light with laser-cut ventilation, and the Women's Race Short is built for freedom of movement with controlled structure that stays clean in silhouette under intensity, unlike loose run shorts that lose shape. The Women's Gym Shorts use a seamless, squat-proof nylon and elastane build with a three-tier waistband for support under load. For women's pieces, then, take your normal size and trust the women's-specific cut rather than comparing to a unisex top.
How do you choose your size with confidence?
Work through it in order and you will land the right size first time.
- Decide your preferred feel: true performance fit or a slightly looser body.
- For a performance fit, take your normal size across tops, shorts and half tights.
- For a looser top, size up one and accept a slightly less fitted chest.
- Remember the fabric stays light when soaked, so tops do not need to be worn tight.
- For women's pieces, use the women's-specific cut and take your normal size.
"Fitted at the chest, relaxed at the stomach is not a style choice, it is what stops a top flapping on the runs and clinging when you are soaked. Size for how you want it to move, not how tight it looks," says the THETA coaching team.
What if you are between sizes?
Being between sizes is common, and the right call depends on the piece and how you race. Consider the tops first: if you are between sizes, take the larger one for training comfort and the smaller one if you want the closest race fit, since the fabric is ultra-light and does not cling when soaked, so a closer fit still breathes. On shorts, lean towards the size that gives a secure waistband without pinching, because a short that slips under load is worse than one that sits slightly closer. Worth remembering too is your session type: if a piece is mainly for hard race simulations you may prefer the closer fit, while a daily-training piece is more forgiving in the larger size. These pieces are precision cut per size rather than simply scaled, so the fit is engineered to work across the range rather than assuming you will size around it. When in doubt across the whole wardrobe, one consistent approach, always your true size, keeps tops, shorts and half tights sitting the same way together.
Common questions
How does THETA sizing run in 2026?
Tops are cut fitted across the chest and relaxed on the stomach, and shorts use a close, fitness-racing-specific fit. Take your normal size for a performance fit, or size up one on tops if you prefer more room through the body.
Should I size up in THETA tops?
Take your normal size for a true performance fit, since the tops are already cut relaxed over the stomach. Size up one only if you specifically want a looser feel through the body, accepting a slightly less fitted chest.
What does fitted chest, relaxed stomach mean for sizing?
It means the top sits close across the chest so it does not flap or snag, while staying easy over the stomach so it does not cling. Use that as your guide to how a top will sit rather than a slim or baggy label.
How should THETA shorts fit?
Shorts use a fitness-racing-specific fit that sits closer than loose run shorts, so they stay put through lunges and burpees. Take your normal size, as the 4-way stretch fabric keeps a closer cut from restricting deep ranges.
Is the women's range sized like the men's?
No, the women's range is engineered by THETA's female athletes for a women's shape rather than shrunk down from a unisex pattern. Take your normal size and trust the women's-specific cut rather than comparing to a unisex top.
Do I need to wear the tops tight to perform?
No, the fabric is ultra-light and does not cling when soaked, so tops perform without being worn tight. Choose the size that matches how you want the top to move rather than sizing down for a compressed feel.
How should half tights fit?
Half tights are designed to sit close and supportive, with a sweat-wicking liner and multiple pockets, so take your normal size. The close fit is intentional and keeps the gel and phone pockets secure without bouncing.
Sources
- HYROX official race format and station standards (hyrox.com)
- THETA product development and Elite 15 testing, 2024–2026
- Established principles of performance apparel fit and construction
Find your fit. Check the fitted-chest, relaxed-stomach cut across the THETA performance kit range, precision cut per size and tested by elite HYROX athletes.