Period underwear for female triathletes

As a female triathlete, one of the areas I’m particularly interested in is managing my training and racing around my menstrual cycle. In recent years,…

Period underwear for female triathletes- which is the best brand?

As a female triathlete, one of the areas I’m particularly interested in is managing my training and racing around my menstrual cycle. In recent years, there has been so much more research into this area (if you haven’t read ROAR by Stacy Sims go buy it now!) The market is responding by developing menstrual products that are about convenience, comfort, and sustainability.

Period underwear is one of the newer innovations on the market which provide an alternative to sanitary pads and tampons for female athletes. I’ve been intrigued by period underwear for a while, but as a triathlete/cyclist one of the first things you learn is you don’t wear underwear! It feels quite counter-intuitive to pull on a pair of knickers under your bibshorts or trisuit!

I normally use a Mooncup during my period as it works well for me- no leaks and no need for any underwear!

What is period underwear?

Period underwear are washable, reusable leak-proof knickers. They look just like regular underwear, but the gusset is made of layers of material which absorbs liquid and wicks away moisture. You simply wash them in the machine after use, there’s no mess or moisture.

Period underwear comes in different absorbancies to wear at different stages of your period from heavy flow through to light. I imagined that it would feel like wearing a wet nappy, but actually the gusset is completely dry… almost like magic!

I tried out 3 different brands to find the best period underwear for female triathletes:


Styles tried:
Ultimate Midi Brief (Heavy flow)- £24.99
Ultimate Bikini (Medium flow)- £19.99

I love that WUKA stands for Wake Up Kick Ass… a motto I can totally get behind! The Ultimate Midi brief has sporty mesh inserts and waistband featuring the WUKA logo, while the Ultimate Bikini style is more subtle with a small red branded tag. Both styles were soft and comfortable for both everyday wear and during training.


Styles tried:
Sporty High Waisted Coni Knickers (Light flow)- £22
Hip Hugger Renee Knickers (Medium flow)- £18

The scalloped edge on BP3 underwear is a lovely detail and makes these knickers feel sexier and more glamourous than you’d expect from period pants. The fabric has a soft, satin texture which adds to the luxury vibe. The Coni style has a super high waist which holds everything in. These almost felt too nice to be wearing on a sweaty run, but they didn’t give me any VPL under my leggings.


Styles tried:
Classic Bikini (Heavy/Overnight flow)- £22
Sensual French Cut Bikini (Moderate/Heavy)- £23.50

I love the lace inserts and the high waist on the French Cut Bikini style-making period underwear sexy! Unlike the other styles, Modibodi recommend washing the knickers prior to first wear to active the technology in the gusset. It is a slight downside as I just wanted to whip them out of the packet and wear them!

Is period underwear for female triathletes?

  • Cycling shorts are designed to be worn without underwear, as the chamois pad is there to protect the soft tissue and absorb sweat. Wearing period underwear with cycling shorts inserts an extra padded layer which starts to feel slightly bulky and causes bunching of the fabrics. Personally, I will stick with a MoonCup when cycling on my period as underwear created a little discomfort.
  • Whether you wear knickers under running leggings is a personal choice. Personally, I prefer to go without, but for some it feels a little too exposed! Whilst all three brands were comfortable to wear while running, I felt more ‘aware’ of my period than I do when I use a MoonCup.
  • Period underwear is also designed to wick away sweat and urine, so they work really well under light-coloured leggings which might usually show sweat and leaks.
  • If tampons or sanitary pads are your regular choice, I highly recommend trying period underwear. Not only are they better for the environment, but they are also better for your body with less chafing and discomfort during exercise.
  • ModiBodi also produce a swimsuit and bikini bottoms, which sound like the perfect practical option for swimming on your period.
  • I tried plain black knickers in every brand, but they actually come in a range of colours and designs.
  • For everyday wear, I love the concept of period underwear and will continue to wear them. However during training and racing, I will stick with my tried and tested MoonCup.

All period underwear was gifted, but opinions are my own.

Have you tried period underwear? What’s your preferred option for training and racing on your period?


  1. Thanks for this, I’m a mum in training for a 10k obstacle race course (involving a lot of mud, water and team mates pulling me up over obstacles. Feeling anxious about little wee leaks on the way. Did you have a favourite that would work for running, getting wet/ keeping mud out etc and are there any you would steer clear of.

  2. This is awesome thank you. Been curious for a while and you have just convinced me to give them a try. My periods are ridiculously heavy so having this piece of mind either when I’m sleeping or exercising will be great.

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