Hello!

March 24, 2025

15 Comments

Shared with permission from The Conversation banner.

When you come home from a run or a sweaty gym session, do you immediately fling your clothes into the washing machine for a hot cycle? Or do you leave them on a chair (or the floordrobe) so you can wear them again tomorrow?

Earlier this year, the French government caused a stir with advice about how often you should wash your clothes. For sports clothes, it recommends up to three wears before you wash them.

This stems from legitimate environmental concerns – each laundry cycle consumes significant water and energy. Frequent washing can also degrade fabrics more quickly, contributing to textile waste.

But what about our health? If the thought of rewearing your stinky t-shirt or damp sports bra makes you squeamish, here’s what you need to know.

Sports clothes and sweat

In the past, exercise clothing was usually made from natural fibres (mainly cotton). Now, it’s mostly made of high-performance synthetic fabrics. These are designed to manage moisture, regulate temperature, improve breathability and control odour.

However, research has shown this kind of exercise clothing, particularly synthetic fabrics, can harbour significant amounts of bacteria after just one use.

Polyester traps moisture, creating the warm, humid micro-environments bacteria prefer.

When clothing is damp, including from sweat, bacteria multiplies substantially much faster. There is a direct correlation between how much bacteria is present and how intense the smell is.

However, research shows innovations in textiles, such as the integration of silver nanoparticles in fibres, essential oil-based treatments, long-lasting antimicrobial treatments and structural fibre innovations are making garments more durable and better at controlling bacteria.

So, is it safe to rewear gym clothes?

This depends on several factors:

Fabric type

Natural fibres such as cotton multiply fewer odour-causing bacteria than synthetics. So if you wear these fabrics to exercise in, they may last a few wears before needing a wash.

Exercise intensity and sweat level

Low-intensity activities that generate minimal or low sweat (including gentle yoga or walking), may allow for more re-wears than high-intensity workouts, as bacterial proliferation correlates directly with moisture levels in fabrics.

(In fact, the French government advice acknowledges how often you wash your sports clothes depends on how much you sweat.)

Season

Climate (temperature, humidity and airflow) significantly affects how much bacteria grows on fabrics. So it may be more reasonable to wash your clothes less in cooler months, when you sweat less.

Personal health

Some people should exercise greater caution rewearing gym clothes. For example, people with skin conditions, compromised immune systems and those prone to skin infections.

Man resting after jogging
How often you wash exercise clothes can depend on the season and how much you sweat. 

So, if you’re wearing a cotton t-shirt and shorts do something light – such as a walk in the cool morning air – you might get away with wearing them again once or twice (especially if you air them properly between use).

But synthetic performance wear, or any clothes you wear to do moderate or intense workouts, should be washed after each use (a cold wash cycle is fine). This is particularly important for garments in contact with high-bacteria areas such as underarms, groin or feet.

Tips for clothes between wears:

  1. Turn garments inside-out (this exposes the bacteria to the air) and hang them up immediately after exercise
  2. Ensure items are completely dry before storing
  3. Store in well-ventilated areas, never in closed containers such as a washing hamper or bag
  4. When possible, hang clothes in the sun – brief UV exposure provides natural antimicrobial benefits
  5. Keep items you’ve worn away from clean clothes.

The bottom line

In the end, it’s up to personal choice – each of us has to weigh up the environmental benefits with potential health concerns and exercise habits.

But some items should always be washed after each use: sports bras and underwear, socks, anything visibly soiled or smelly, and any clothing worn during high-intensity workouts or in hot weather.


Carolina Quintero Rodriguez, Senior Lecturer and Program Manager, Bachelor of Fashion (Enterprise) program, RMIT University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

  • This actually makes some sense since I used to do judo and we would all wash our judogi (uniform) after 3-4 uses since its 100% cotton and very easy to shrink. And this was after very heavy sweating during each session despite wearing an undershirt. But in saying so, my friend has dermatitis so he would wash after every use so at the end of the day I guess when to wash is a personal thing.


  • I wash my workout clothes weekly. I train on my own so I’m not offending anyone with my smell.


  • Gosh I wash my clothes after every use especially when I sweat in them! I just can’t stand the smell and worry that I will be offensive to others. I used to own a store where we shared a public toilet with a cafe that a lot of cyclists would visit. The stench of their mildew smelling sweaty lycra literally encased the whole room.


  • I walk for an hour every day and then workout for an hour each day. For these 2 hours, I wear workout clothes that get washed every week. A bit pongy but I dont go near other people so all good


  • Interesting read. I think it comes down to common sense. I’ve been turning my garments inside out for ages and not just exercise clothes either. And it depends on the type of material too. Some fabrics harbour more odours than others so wearing them a second time without washing mightn’t be the best option.


  • I’m not sure you can have a hard and fast rule for something like this. It really depends on so many factors. Personally, I’ll put workout gear in the wash after each wear, but if I haven’t been particularly sweaty, it might get 2 wears before a wash. In Summer, I’m more likely to need to wash more frequently than in winter. Also depends if I’m going for a run, or just doing a yoga class.


  • I saw a segment on the news regarding how often exercise clothes should be washed – it was funny how there were so many different suggestions from different people. I swim daily at the local pool and wash my bathers and towel every single time to get rid of the chlorine smell.


  • Thanks for this article as I had only heard about it in passing and didn’t hear the full story. It all depends on what time of day I go for my exercise and how the weather is. I usually exercise in the cool of the mornings and rarely work up a heavy sweat. I might wear an article twice, depending on the circumstances.


  • I wash after each use, but on cold cycle. A hot cycle would ruin my clothes too quickly.


  • I know studies and recommendations have shown you can rewear activewear/sports clothing but I just can’t bring myself to do it. I am an individual that unfortunately suffers from body odour and I would just hate to be that person in the gym that “stinks” due to rewearing my gym gear.


  • Okay, so I go for a 10km run 3 times a week and a 5km once a week, basically 4 days in a row I exercise. It only takes me an hour to run 10km. I rewear my exercise clothing for the whole week. 3 of the 4 days I am going early morning, so they are not overly sweaty due to the cool air and I always spread them out on top of my tallboy to dry and they are completely dry before my next wear each time. Yes, I rewear the socks as well. I don’t really see the difference between wearing items of clothing all day and that being fine, as opposed to wearing something for what equates to 3.5hours.


  • I always wash my clothes after each wash unless i am on holiday and it is a bit hard to wash these items. The thought of wearing dirty clothes after sweating in them doesn’t sit well with me and i would prefer to wash mine after every use. It was a great article to read though, thank you for sharing.


  • Definitely gross for me! Outside clothes once worn go into the wash. Only with the exception of things like jackets, jeans and thicker wear when only lightly used. And that only gets another wear IF there are no smells on it, from things like being in a place with food etc.


  • I would love to say I can get multiple wears from my exercise clothes but it feels so gross putting them on the next day. I’m one of the cute ones that sweats buckets at a slight incline so when I actually work out it’s noticeable. I’d have to hang them inside-out outside!


  • Honestly, If I’m exercising, i want to work up a sweat and if I’m sweating I’m washing my clothes after I’ve worn them. Rhe thought of rewearing gym clothes is really not appealing at all. The only thing I will hang out and re- wear are my bathers after a swim.


Post a comment

To post a review/comment please join us or login so we can allocate your points.

↥ Back to top

Thanks For Your Star Rating!

Would you like to add a written rating or just a star rating?

Write A Rating Just A Star Rating
Join