You should wash training kit at around 30°C on a cool, gentle cycle, because cool water cleans synthetic performance fabric fully while protecting the heat-sensitive elastane that gives it stretch and recovery. As of 2026, 30°C with a plain liquid detergent and no fabric softener is the setting that keeps technical kit performing and lasting; hotter washes shorten its life without cleaning any better.
- 30°C is the sweet spot: hot enough to lift sweat oils with the right detergent, cool enough to spare the elastane and heat-sealed seams.
- Heat, not water, degrades performance fabric; washing at 40°C or above accelerates elastane breakdown and can distort ultra-light race kit.
- THETA's Tech and Race lines blend polyester or polyamide with elastane and use heat-sealed construction, all of which reward a cool wash.
Why is 30°C the right temperature?
The odour and grime in training kit come from skin oils and bacteria, and those lift with a properly dosed detergent rather than with heat. At 30°C a plain liquid detergent has more than enough cleaning power for synthetics, so raising the temperature adds nothing on the cleaning side while adding real damage on the fabric side. Consider what that heat reaches: elastane, the fine stretch fibre knitted through THETA's shorts, tops and half tights to give them their 4-way stretch and snap-back, relaxes and breaks down as the water warms. A cooler wash protects exactly that fibre. Cool washing also uses less energy, which quietly lowers the running cost of maintaining a kit rotation.
What happens if you wash too hot?
Hot washing attacks the very features that make performance kit worth owning. Elastane loses its elasticity, so waistbands slacken and tops lose their fitted-chest shape after fewer washes. Ultra-light race fabric can set creases or distort, and heat-sealed pockets and fused seams, which rely on bonded material rather than stitching, can be stressed at higher temperatures. Hot water can also bake sweat oils deeper into the fibres, which is why some kit smells worse after a hot wash rather than better. In short, heat trades a small perceived deep clean for a measurable loss of lifespan and performance.
Are there times to go warmer or cooler?
The temperature can flex slightly with the job, but the safe range stays narrow. Use this guide:
| Situation | Temperature | Notes |
|---|---|---|
| Everyday sweaty session | 30°C | Default; plain liquid detergent, no softener |
| Ultra-light race kit | 30°C, gentle, mesh bag | Gentlest handling; protect light seams and vents |
| Heavy odour or chalk | Cold pre-soak, then 30°C | Vinegar soak first; heat is not the answer |
| Non-technical cotton items | Up to 40°C | Only for garments with no elastane or ventilation |
Does temperature affect smell?
Many people wash hot hoping to kill odour, but that misreads the problem. Odour comes from oils and bacteria trapped in the fibres, and the reliable fix is a cool wash with the right detergent, plus a cold vinegar pre-soak for stubborn cases, not a hot cycle that can set the smell deeper. Prompt washing matters more than temperature: leaving damp kit in a bag lets bacteria multiply before the wash, so getting kit into a cool wash soon after training does more for freshness than turning up the heat. Drying fully and quickly afterwards, on a rack rather than in a hot dryer, completes the job.
How does temperature fit the wider care routine?
Temperature is one lever among several, and they work together. A 30°C wash only delivers its full benefit alongside a gentle cycle, plain liquid detergent, no softener, and air-drying, because a cool wash followed by a hot tumble-dry still cooks the elastane. It helps to picture the whole loop the way the kit was made: the race team knit, cut and heat-sealed these pieces, then wore and washed them across two seasons on the assumption of cool, gentle care, which is how the Tech and Race lines reach their two-plus years of hard use. Setting the machine to 30°C, then hanging kit up to dry, is the whole routine in two steps, and it is the cheapest way to protect a durable rotation. Get the temperature right and the rest of the care becomes easy.
"Thirty degrees cleans training kit perfectly. People wash hot because they think it kills the smell, but heat just cooks the stretch out of good fabric. Cool wash, no softener, air-dry, and your kit lasts," says the THETA coaching team.
Common questions
Can I wash performance kit in cold water?
Yes. Cold water is safe and effective for synthetics when paired with a good liquid detergent, and it is ideal for pre-soaking smelly or chalky kit. A 30°C wash is marginally better at lifting oils in a single cycle, but cold works well for routine loads.
Is 40°C ever okay for training kit?
It is not recommended for elastane-blend or ventilated technical kit, because the extra heat degrades stretch and stresses seals without cleaning better. Reserve 40°C for non-technical cotton items that contain no elastane or ventilation.
Does hot water clean sweaty kit better?
No. Sweat oils and bacteria lift with the right detergent, not with heat, and hot water can bake odour deeper into synthetic fibres. A cool wash plus a cold vinegar pre-soak for stubborn smells outperforms a hot cycle.
Will a cool wash kill bacteria in my kit?
A cool wash with proper detergent removes the oils bacteria feed on and flushes most of them out, which is what stops odour returning. Washing promptly after training and drying fully matters more for freshness than trying to sterilise kit with heat.
What temperature protects elastane best?
The cooler the better within a practical range, so 30°C or a cold wash preserves elastane most effectively. Elastane is heat-sensitive, so keeping washing and drying temperatures low is the main way to protect a garment's stretch and recovery.
Does washing cooler save money?
Yes. Heating water is the biggest energy cost of a wash, so 30°C or cold cycles cut running costs, and they extend kit lifespan too. Cheaper to run and gentler on kit, cool washing is the better choice on both counts.
Sources
- THETA product construction notes and coaching data, 2024–2026
- Established textile-care principles (elastane heat sensitivity, detergent surfactant action, energy use)
- HYROX training and sweat-load context (hyrox.com)
Kit that rewards a cool, simple wash. THETA's Tech and Race lines are built from elastane blends and heat-sealed construction tested over two seasons. Explore the THETA performance kit range.