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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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Based on 10 review(s)
Write an online review and share your thoughts with other shoppers!
Zoe - Hove

We are delighted with our two core warmers

We are delighted with our two core warmers , which have really made a difference in raising our temperature after coming out of the cold sea at Brighton. The communication from Seabirds was also excellent and we are happy to support a great community resource

Su Lewis - Weymouth

Everyone should get one!

Having received one of your core warmers as a Christmas present from my daughter, I bought one for my regular swim buddy, as she was so jealous. We always wear them after swimming in the sea here in Weymouth and they make such a difference to the length of time it takes to get warm again. I've also taken to wearing mine on the allotment on cold days. Such a wonderful thing. Everyone should get one!

Val - St. Austell

Just ordered another one

I'm really pleased with my pink Haramaki. I ordered it as part of my sea swim change gear and it's working really well as a dual purpose garment (boob tube/ belly warmer). It's keeping its shape well, is super stretchy and, most important, is lovely and warm.

Julian - Hythe

I placed an order for several members of my family who all love them

My sister lives in windy Hythe and first gave me a vague description of what turned out to be your core warmers/haramakis. A quick wiki later and I arrived at your website and was pleased to see that you're based in another breezy seaside place, where my daughter lives. Although I'd never heard of core warmers, I placed an order for several members of my family who all love them and find they're really effective - I just need to get one for myself now!

kate webster - hove

Essential and well loved:)

Wasn't sure what the point was until I borrowed one! It somehow warms you up immediately, you can tuck hot water bottle inside and it stay snug. Also find myself wearing it on cold winter days especially on long walks.

Claudine - Hove

Lovely warm middle

Love it. Keeps me warm after a swim or on a chilly day. Adds a bit of colour between my dark layers!


Excellent idea for post swim and for chilly bike rides

I wasn't really sure I needed one of these, but now I have one, I want another! Excellent for warming up after a chilly swim, but also found it brilliant to wear on winter cycle rides, particularly when cycle tops ride up.

Sarah -

I was sceptical at first but now I swear by these. They can make all the difference when warming up after getting out of the water. Great for period pain too! Shove a mini hot water bottle in there...fantastic.

Samantha Wilson - Brighton

A small thing that makes a big difference. An essential peice of kit to help you warm up quickly after swim. Lovely quality and a good price.

Elaine - Cumbria

I swear by these in the winter - makes a huge difference. Really helps you warm up quicker after a swim. I wear mine ALL THE TIME :)