Sports Bra Fitting: A 6-Point Check for Mums

I have lost count of the number of women who have told me they avoid jumping, skipping or jogging in class, and when we talk about it the reason is not fitness at all. It is their bra. It moves, it digs in, it rubs, or it simply does not hold anything. If that sounds familiar, a proper sports bra fitting might do more for your workouts than any new trainer, app or programme.

I am a coach, not a lingerie fitter, so for a full professional fit I would always suggest visiting a shop with trained fitters. But a lot of women have never been shown what a good fit should feel like, so here is a simple checklist you can use at home or in the changing room, plus what to know if your body has changed after pregnancy or breastfeeding.

Why a well-fitted sports bra matters

Breasts move a surprising amount during running and jumping, up and down, side to side and in and out. A badly fitting bra can mean discomfort, chafing, shoulder and neck tension, and a real reluctance to try anything bouncy. A good one lets you forget about it and focus on the session.

It also changes how people move. In my classes I notice women who are uncomfortable often shorten their stride, hunch their shoulders or hold an arm across their chest during jumps. Better support usually means better form.

Sports bra fitting: the 6-point check

Put the bra on, adjust it, then go through these one by one.

1. The band. This does most of the support work, not the straps. It should sit level all the way round, front and back, and feel firm. You should be able to slide two fingers under it but not much more. If it rides up at the back, it is too loose.
2. The cups. No spilling over the top or sides, and no wrinkles or gaps in the fabric. If there is spillage, try a bigger cup. If there is wrinkling, try a smaller one.
3. The underwire (if there is one). It should sit flat against your ribcage and surround the breast tissue, not sit on it. If it digs in under your arm, the size or style is wrong.
4. The centre front. On an encapsulation-style bra (separate cups), the middle panel should sit flat against your breastbone.
5. The straps. Snug but not digging in. If you find yourself tightening them a lot to feel supported, the band is probably too loose.
6. The movement test. Jog on the spot, do a few star jumps and swing your arms like you are punching. Watch in the mirror. Some movement is normal, but it should feel controlled and comfortable.

Always fit a new bra on the loosest hook. Bands stretch over time, and you can move to tighter hooks as they do.

Compression or encapsulation?

• Compression bras (the crop-top style) press the breasts against the chest. Often fine for lower-impact training and smaller cup sizes.
• Encapsulation bras have separate cups, a bit like a normal bra. They usually suit larger cup sizes and higher-impact training.
• Combination bras use both and are popular for running and class workouts.

For a bootcamp class with some jumping, skipping or boxing, most women do best with a medium to high support bra. Front-adjustable straps and a hook fastening at the back make life a lot easier than wrestling a pull-over crop top on and off after a sweaty session.

Changes after pregnancy and breastfeeding

Your bra size can change during pregnancy, while breastfeeding, after you stop and as your body settles in the months that follow. Many women carry on wearing their pre-baby sports bra and wonder why it no longer works. A few practical tips:

• Get re-measured after each stage. Size is likely to shift more than once in the first year or so.
• Consider a nursing sports bra while feeding. Clip-down cups make life simpler between a feed and a workout. Some women find feeding or expressing before exercise makes them more comfortable.
• Avoid very tight compression while breastfeeding if it feels uncomfortable or presses hard. If you notice a painful, red or hot area on your breast, see your GP or midwife promptly.
• Take it slowly. Return to higher-impact exercise only after your GP has given you the all-clear at your postnatal check, usually around 6 to 8 weeks. The NHS page on your 6-week postnatal check explains what to expect. If you are getting back into jogging, read my guide to running after baby.

Any new lump, change in shape or skin, or nipple change should always be checked by your GP, whatever bra you wear.

Caring for your sports bra

• Wash on a cool cycle, ideally in a laundry bag, and fasten the hooks first.
• Skip fabric softener, which can affect stretch and wicking.
• Air dry rather than tumble dry.
• Replace it when the band feels loose on the tightest hook, the fabric has lost its spring or the support feels weaker during jumps.
• Have at least two if you train a few times a week, so one can rest between washes.

Getting ready for your first class

A good bra, comfortable trainers with a bit of grip, water and a towel are honestly all you need. My post on what to bring to a bootcamp class covers the rest.

In my classes, every exercise has a lower-impact option. If you are not ready for jumps, you can do step-backs or marching instead and still get a great workout. Many women love the SYP Box Fit beginner boxing class because it is a full-body session that is easy to adjust, with no sparring.

FAQs

How should a sports bra fit?

Firm and level around the band, with two fingers’ room underneath, no spillage or gaps in the cups, straps that do not dig in, and controlled movement when you jog or jump on the spot.

Should a sports bra be a size smaller?

Not automatically. A sports bra should feel firmer than an everyday bra, but going too small can cause digging, rubbing and restricted breathing. Try your measured size first and judge by the fit checklist.

How often should I replace my sports bra?

It depends how often you wear and wash it. Replace it when the band has stretched, the fabric is tired or the support feels weaker, and get re-measured after pregnancy, breastfeeding or any big change in your body.

Can I wear a sports bra while breastfeeding?

Yes, many women do. A nursing sports bra with clip-down cups is convenient. Avoid anything that presses painfully, and speak to your GP, midwife or health visitor if you have breast pain or feeding concerns.

Book your first class

Once your kit is sorted, come and put it to the test. SYP Bootcamp runs 45-minute small-group classes for mums and dads in a church hall in Archway N19, maximum 10 people, every level welcome, £15 a class. Book your £15 class here or call or WhatsApp me on 07301 512215 if you have any questions. If you would like to see how 1-1 coaching works alongside classes, here is how personal training with me works.

About the author

Artem Olekhnovych is a personal trainer in Archway and the founder of SYP Fitness and SYP Bootcamp. He has coached clients in Archway, Highgate and across North London for over 10 years, and runs small-group bootcamp classes for busy mums and dads. Read reviews from his 1-1 clients.