Your HYROX race number belt should go over your singlet, sitting on the outside so your bib stays visible and flat while you move. As of 2026 that keeps the number readable for timing and judges, stops the belt trapping a wet top against your skin, and lets you spin it out of the way for the sled and lunge stations.
- HYROX requires your race number to be visible, and a bib belt worn on the outside keeps it flat and readable.
- A singlet or race top sits closest to the skin for wicking, with the belt layered over the top.
- In THETA's coaching data, belt fiddling mid-race is a common time leak that a proper setup removes.
Why does the belt go over the top?
Picture the wall balls: you are soaked, your chest is heaving, and a judge is counting your reps from across the lane. Your number has to stay visible for that whole race, so it belongs on the outermost layer where nothing covers it. Wear the belt under your singlet and the fabric hides part of the bib and bunches over the belt, and a soaked top then pins the belt against your skin, which chafes. Worn over the top, the belt sits on a smooth surface, the number stays flat, and you can rotate it around your waist so it never sits under the sandbag or across the sled straps.
How should the singlet fit under the belt?
Your top does the wicking, so it needs to sit close and stay light when soaked, which is exactly what a race singlet is built for. THETA's Race Singlet is an ultra-light shell with laser-cut airflow and reinforced shoulders and hem, so it holds a clean line under a belt rather than bunching. A fitted cut means the belt clamps onto a flat surface instead of gathering loose fabric, and the reinforced hem stops the belt riding the fabric up as you move. A loose vest, by contrast, balloons over the belt and feels messy from the first run onwards.
| Setup | Visibility | Comfort |
|---|---|---|
| Belt over fitted singlet | High, bib flat and clear | Best, belt on smooth surface |
| Belt over loose vest | Medium, fabric bunches | Fabric gathers under belt |
| Belt under top | Low, top hides bib | Chafe, belt pinned to skin |
| Bib pinned to top | High but rigid | Pins tear wet fabric, less adjustable |
"Wear the belt over the singlet, set the tension once in the pen, and forget it. Anything you're adjusting on the run is a second you didn't need to lose," says the THETA coaching team.
How do you set the belt so it never gets in the way?
Sort it in the start pen, before the gun, so it holds through all 8 stations without a second thought.
- Put on your singlet first, then fasten the belt over it at the waist.
- Tighten so it does not ride up on the runs but does not dig when you breathe hard.
- Position the bib at the front where judges can read it clearly.
- Spin the belt so the buckle sits at your side, away from the sandbag contact point.
- Do a few lunges and a mock sled brace to confirm it stays put.
Should you ever pin the bib to your top instead?
A belt beats pins for HYROX because pins tear wet technical fabric and lock the number in one spot. By the time you reach the sandbag, the top is soaked and stretched, and safety pins pull at the laser-cut or woven ventilation and can rip the fabric under the load. A belt keeps the number rotatable and protects the garment, which matters if you want your race top to survive many races. If your event mandates pinning, use all four corners and keep them clear of the reinforced seams.
Common questions
Should the HYROX race belt go over or under the singlet?
Over the singlet, so the number stays visible and flat and the belt sits on a smooth outer surface. Worn underneath, the top hides part of the bib and a soaked top pins the belt to your skin and chafes.
Why not just pin the number to my top?
Pins tear wet technical fabric and lock the bib in one place, whereas a belt is rotatable and protects the garment. If pinning is required, use all four corners and keep the pins away from ventilation holes and reinforced seams.
How tight should the race belt be?
Tight enough that it does not ride up on the runs, but loose enough that it does not dig when you breathe hard under the sled or wall balls. Set the tension once in the start pen and test it with a few lunges before your wave.
Where should the buckle sit?
Rotate the belt so the buckle sits at your side, clear of where the sandbag rests on your shoulders and back and away from the sled straps. This stops the buckle digging in during the loaded stations.
What top works best under a race belt?
A fitted race singlet is ideal because it stays light when soaked and gives the belt a flat surface to clamp onto. THETA's Race Singlet uses laser-cut airflow and reinforced hem so it holds its line rather than bunching under the belt.
Will the belt chafe during the race?
A belt worn over a smooth, fitted top rarely chafes, but a belt over a bunching loose vest or worn against the skin can. Keep it on the outside, set the tension correctly and apply anti-chafe balm at the waistline if you are prone to it.
Can I move the number during the race?
Yes, that is the advantage of a belt, you can spin it around your waist to keep the bib clear of the sandbag or sled while staying visible. Just make sure the number faces forward for judges at each station.
Sources
- HYROX official race rules on number visibility (hyrox.com)
- THETA coaching data, 2024–2026
- THETA 2026 Race collection construction notes
Set it once, race clean. A fitted race singlet gives your belt a flat, light surface that holds all race. Explore the THETA Race Collection in THETA performance kit, tested by elite HYROX athletes.