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Sweaty Betty

Online only

Therma Boost Thermal High Waisted Leggings

£110

£44

Colour

Out of stock online

    Sale items

    Waist

    Free standard delivery over £60

    Product code: T129537S

    About this style

    Stay warm during cold-weather workouts in these thermal insulated leggings from Sweaty Betty. Made from stretchy fabric with a soft, brushed fleece lining that thickens the material for added insulation, they provide good warmth for winter fitness activities and runs without restricting movement. The high rise elasticated waist ensures a skinny fit that stays in place during active exercise, while practical details include side slip pockets and a secure back zip pocket. Part of the brand's HeatProtect range, these comfy lady's activewear leggings offer effective temperature regulation for yoga, sport, running and other active pursuits, and help keep you dry whatever the weather throws your way.

    Curated By

    Details & care

    Fit and style

    Skinny fit

    Elasticated waist

    Mid rise

    Composition

    76% polyester, 24% elastane

    Care

    Machine wash according to instructions on care label

    Delivery, collection & returns

    Delivery

    Standard

    Free over £60, or £3.99

    Returns

    UK returns

    Free. Returns can only be arranged via postal options. Exclusions apply Full delivery and collection information Our returns policy

    Exclusions apply

    Full delivery and collection informationOur returns policy

    About Sweaty Betty

    Empowering women through workouts and beyond since 1998, Sweaty Betty’s iconic fitness gear will support you in reaching your fullest potential.

    Reviews (53)

    4.7

    77% Recommended this product

    Mentions
    01 December 2025Salruns

    The comfiest winter leggings

    Originally posted on sweatybetty.com

    Yes, I recommend this

    I run in the fells an mountains every day and these are my favourite winter leggings. I know SB isn't thought of as a technical mountain brand but these are under-rated for performance gear. I even use as a base layer for ice climbing and winter mountaineering. Super flattering. No hardcore wind or water resistance, but breathe and stay pretty warm when soaked e.g. after stream crossings. They're not too small - they're TTS (and exactly the same as last winter) but you're not going to get away squeezing into a smaller size like you can with the powers. Might feel thin but still hold up - got tangled in brambles today and no rips.

    Helpful?

    18 November 2025RaSp

    Disappointing and Cold

    Originally posted on sweatybetty.com

    No, I don't recommend this

    I bought these in the Spring sale earlier in the year to replace previous pairs of "EcoTherm leggings" and finally got them out in recent weeks and I am so disappointed. I have noticed a general reduction in quality across a lot of SB leggings recently and these are no different, much thinner than previous versions and the fit feels cheap and baggy. I washed them after a couple of wears in hope that it might revive the fit but again after just one wear they have lost their shape and above all, they are not warm in the slightest. Only nice thing is the colour!

    Helpful?

    20 July 2025VKW-22
    Verified Purchase

    Lovely

    Originally posted on sweatybetty.com

    Yes, I recommend this

    Fit nicely, very comfortable and will look forward to wearing these when it’s cooler.

    Helpful?

    16 July 2025BridgeBallet
    Verified Purchase

    Lovely leggings, sizings were a little inconsisten

    Originally posted on sweatybetty.com

    I love the leggings however I have found the sizing to be inconsistent. I was given an XS pair a couple of years ago that fitted perfectly. So I ordered a pair in the same size last year, only to find them really quite tight. So thinking the sizes had changed, I ordered small this time around. These were huge, so I've had to return them and re-order an XS. I'm guessing the ultra small pair, were accidentally mis-labelled. Other than this, they're very good quality and comfortable.

    Helpful?

    06 July 2025Chris28
    Verified Purchase

    Thermo boost leggings

    Originally posted on sweatybetty.com

    Yes, I recommend this

    I bought these in the sale for next winter as previous pairs were lovely for frosty runs. They feel soft and cosy hopefully will not get too warm during my runs, as my previous pairs did not. At 5 foot 3 I did order the full length which are slightly too long, but I think I will prefer that in the winter than a bit of bare leg with the 7/8th length, but I will have to wait for the colder weather to try them out. I find the pockets very useful, especially when running alone, I want my phone in case of any difficulties or harassment. Sad that this is how women have to prepare these days.

    Helpful?

    27 June 2025Nutless
    Verified Purchase

    Good leggings

    Originally posted on sweatybetty.com

    Yes, I recommend this

    Great leggings but very small sizing, need to go up at least a size

    Helpful?

    18 June 2025Charlotte p
    Verified Purchase

    Therma boost leggings

    Originally posted on sweatybetty.com

    Yes, I recommend this

    I purchased these for a winter trip to Scotland. They are perfect for colder days, but not the wind. I had to still layer up.

    Helpful?

    05 April 2025Susmo65
    Verified Purchase

    Best ever base layer

    Originally posted on sweatybetty.com

    Love the warmth and the soft feel against my skin . Resent the fact that I go to the trouble to submit a review, then am told it is too short! So is my time!

    Helpful?

    17 March 2025Elb75

    Different to my other pair??

    Originally posted on sweatybetty.com

    I bought these leggings in black as a second pair whilst my others are in the wash but so disappointed, same product and size ‘S’ as the pair I’ve already got in grey, but material not as nice, much tighter around the waist and shorter in the leg! I paired them up with my current ones and they’re smaller and shorter! Why??

    Helpful?

    16 March 2025Doddy123
    Verified Purchase

    Best leggings I’ve bought

    Originally posted on sweatybetty.com

    Yes, I recommend this

    I was recommended these leggings by a friend. The most expensive leggings I’ve bought but totally the best. Great quality and fit, so comfortable they are like a second skin. The material is so soft and they look fantastic. They stay perfectly in place - I’ve worn them for running, walking and in the gym. I’m definitely buying all the other colours.

    Helpful?

    02 March 2025Civs88
    Verified Purchase

    Warm, comfortable and keep me warm coaching.

    Originally posted on sweatybetty.com

    Yes, I recommend this

    Bought for winter running, warm, feel comfortable and good relective light for low light/dark running. Good sized side pockets. I use them for run coaching and instructing bootcamp and they keep my legs warm in our cold northern climate.

    Helpful?

    27 February 2025
    Verified Purchase

    Happy at Half Price!

    Originally posted on sweatybetty.com

    I finally replaced my old SB thermal leggings after 6 years! These are much thinner but toasty warm and so far impressed. Whether they last as long ummm doubtful …. The quality does not seem as good but maybe technology has improved! I am 5ft9 and they are a tiny bit short. Looked shorter when they came out of the packet, but were much better on. I used my birthday code so got value for money. Unsure whether I would want to buy full price. I bought a medium which is my usual SB size and they initially felt a little snug but fine after 2 wears.

    Helpful?

    20 February 2025Runnermom!
    Verified Purchase

    Winter running leggings

    Originally posted on sweatybetty.com

    Yes, I recommend this

    I have other pairs of Sweaty Betty running pants which I love and kept wanting the winter pants. I am so glad I finally got them!! Can’t believe I waited so long, much better for the winter running!!

    Helpful?

    13 February 2025Craig18
    Verified Purchase

    Great fit.

    Originally posted on sweatybetty.com

    Wife loves them. Really comfortable and look great on.

    Helpful?

    06 February 2025Tiateacake
    Verified Purchase

    Nice and warm

    Originally posted on sweatybetty.com

    Yes, I recommend this

    Loving these leggings for colder days and wishing I had bought two pairs. They definitely do not fall down.

    Helpful?

    06 February 2025MMorin
    Verified Purchase

    10/10

    Originally posted on sweatybetty.com

    Yes, I recommend this

    These are one of the most comfortable leggings I have purchased!

    Helpful?

    29 January 2025Jul05
    Verified Purchase

    Lovely leggings

    Originally posted on sweatybetty.com

    Yes, I recommend this

    I love these warm and soft leggings. I have been wearing them a lot, both when coaching and also when running on cold days.

    Helpful?

    27 January 2025Nadia_
    Verified Purchase

    Review

    Originally posted on sweatybetty.com

    Yes, I recommend this

    True to size, warm and extremely comfortable for Zumba and Pilates

    Helpful?

    18 January 2025JennT

    Warm, lovely but too short!

    Originally posted on sweatybetty.com

    Yes, I recommend this

    These are too short! I’m 5’8 and the full length is just below mid calf. I wish you would do a 9/8 length..my daughter’s idea and I think it’s brilliant! Lots of people have longer legs these days.

    Helpful?

    16 January 2025Tf I
    Verified Purchase

    Warm and cosy

    Originally posted on sweatybetty.com

    Great fit and in this cold weather lovely and warm and so cosy

    Helpful?

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