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Beat the after-drop with a cotton/lycra core-warmer
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A key bit of our winter swim kit - Core-warmer or Haramaki. Also known as: kidney warmer,  belly-warmer, bump band, tummy tube, body warmer, back-warmer...

The haramaki is a traditional Japanese item of clothing. A tube of soft, stretchy fabric that you pull on and wear around your middle. It has been called a boob tube for your middle. A 'core warmth' effect spreads to the rest of the body. Fantastic for a quicker recovery when getting out of the sea. Helps with the cold that comes after swimming when you continue to cool after getting out by layering you up quicker. You can stuff a hot water bottle down it for extra warmth and it will hold it in place. 

These haramaki core-warmers from Brighton based sea swimmer NukuNuku will keep you warm and keep their shape wash after wash.

NukuNuku’s Black Haramaki in cotton with lycra. A tube of stretchy cotton to pull on or step into and wear around your middle that will keep your whole body warm by layering your core. An essential basic for your swim kit.

  • Made in the UK 
  • Built to last and keeps its shape
  • High quality soft organic* cotton 
  • With added lycra for stretch 92% cotton, 8% Lycra 190gsm
  • Hugs your body round your core
  • Helps warm your whole body
  • Unisex
  • Available in sizes XS to XL

The haramaki is a traditional Japanese item of clothing worn under or over clothes around the middle to keep you warm. Unisex and ageless - for anyone who wants to banish the cold. They took this Japanese idea and made their own brand single layered soft cotton haramaki core-warmer to keep you warm and keep its shape wash after wash. Wearing these tummy-wraps will keep your core warm and allow your whole body to stay warmer. 

May aid digestion and ease lower back pain, covers you up during sports such as pilates, cycling and yoga and allows you to stay outside for longer. Warning, you can become addicted - we wear ours 24/7...

NukuNuku's haramaki core-warmers are single layered and average 30cm from top to bottom, covering your kidneys and lower back to top of the hips. 

Sceptical and think you don’t need one? You may be if you haven’t yet tried them (but you will be hooked when you do!) You can test it out by tying a scarf round your waist to try the effect. Soon you will see that having the core of your body insulated raises your body temperature all over. This is because the inner organs are warm, increasing your circulation, which spreads heat all over your body, even to the toes and fingers.

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Customer reviews

(15 Customer reviews)
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Showing 1 to 5 (15).

Lightweight and cosy

Easy to step into and can fit in pocket of my dry robe.

Anne MacKenzie | Highland | September 2022

Warming the Core

This product was recommended to me by a fellow cold-water swimmer and I used it for the first time at the weekend. It made such a difference that I mentioned it in my swimming blog and a friend has now ordered one. It's so simple, yet so effective. I love it!

Emma Prince | Worthing | December 2021

My swimming must have

I used to get out of the water, get dressed and would be so cold that it would take me a while to warm back up. But now I have used this a couple of times, I put this on first then the get the rest of myself dressed and I can honestly say I do not feel so cold. Iv stopped shivering and I feel so much warmer when Im having my hot drink and cake 😋 and feel like I stay and chat with the girls a lot longer afterwards which has my swimming experiences a lot more better. Thank you for selling these Seabirds they have made a huge difference to my life.

Nadia swan | Polkerris, Cornwall | October 2021

Core warmer

Bought as a gift for a friend, she seems very pleased. Will order one for myself.

Andy | Pembrokeshire | October 2021

Easy and effective

Its easy to pull on after sea swimming and I feel safer knowing it will help my core to warm up.

Ruth McCabe | Suffolk | October 2021

Showing 1 to 5 (15). Page 1 of 3.