How to Stop Chafing When Running: Proven Tips for Runners

Chafing is one of those running problems that tends to announce itself at the worst possible moment — somewhere around mile 18 of a marathon, or during a rain-soaked long run when wet fabric has been rubbing for the past hour. For many runners, it's not a matter of if, but when.

The good news is that chafing is almost entirely preventable. With the right kit, a few simple habits, and an understanding of where and why it happens, you can run for as long and as hard as you like without it becoming a problem. This guide covers everything you need to know.

What is chafing and why does it happen?

Chafing is skin irritation caused by repeated friction. During running, this friction comes from two sources: skin rubbing against skin, or skin rubbing against fabric. Over time — especially across longer distances — this repeated contact breaks down the surface of the skin, causing redness, rawness, and in more severe cases, open sores or bleeding.

Several factors make chafing more likely:

• Moisture. Sweat softens the skin and increases friction. When sweat dries and leaves salt crystals behind, those crystals can intensify irritation further — a particular issue on long efforts in warm weather.

• Distance. The longer you run, the more repetitions of any given movement. A slight rubbing that barely registers at 5K can become a serious problem at 20 miles.

• Fabric type. Cotton absorbs moisture and stays wet against the skin. Technical fabrics wick sweat away, reducing the damp conditions in which chafing thrives.

• Fit. Loose fabric bunches and moves; seams in the wrong places grind against skin with every stride.

• Body shape and size. Chafing can affect any runner, but areas with skin-on-skin contact — inner thighs, underarms, between the toes — are particularly vulnerable.

Understanding the mechanism matters because the prevention strategies all follow from it: reduce moisture, reduce friction, and remove the conditions that allow both to build up.

What are the most common chafing hot spots?

Knowing where chafing is most likely to strike means you can target your prevention before it becomes a problem. The most common areas for runners are:

Inner thighs. The most frequently affected area, particularly for runners whose thighs make contact during their stride. Worsens significantly with heat and moisture.

Underarms and chest. Caused by fabric — usually the armhole edge or chest seam of a vest or t-shirt — rubbing repeatedly with arm movement. More common in ill-fitting kit or with heavier fabrics.

Nipples. Particularly common in male runners during long distances. The combination of moisture, a fine fabric, and thousands of repetitive strides can cause significant soreness and even bleeding. Race photos are full of evidence.

Feet and toes. Where socks or shoe seams meet skin. Blisters are a form of chafing — a fluid-filled response to localised friction. The same principles of moisture management and layer reduction apply.

Waistband area. Running packs, hydration belts, or shorts with tight waistbands can rub across the lower back and hips on longer efforts.

Groin. Particularly relevant for longer distances and trail running, where movement patterns are more varied and kit may shift more.

How can I prevent chafing?

Prevention comes down to three pillars: the kit you wear, the products you apply, and how well you look after your skin.

Choose the right gear

Technical running fabrics

The single most impactful change most runners can make is moving away from cotton and into technical running fabrics. Polyester and nylon blends designed for running are engineered to wick moisture away from the skin, which removes the damp conditions in which chafing thrives. Look for fabrics labelled as moisture-wicking, quick-dry, or sweat-wicking — these are not marketing terms, they reflect genuine differences in how the fabric behaves against wet skin.

Fit

Loose kit moves. Movement against skin means friction. Well-fitting running kit — shorts, vests, tights, and tops that sit close to the body without being restrictive — eliminates most of the unnecessary fabric movement that causes chafing. Pay particular attention to seam placement: a seam running along the inner thigh of a pair of shorts, or across the nipple line of a vest, is a design detail that will make itself known on a long run.

For shorts specifically, twin-skin construction is worth understanding. Rather than a single layer of fabric against the skin, twin-skin shorts — like the Women's Tech 4.5" Twin Short or Men's Tech 5" Twin Short — use two separate layers that move independently of each other. Friction happens between the layers, not between the fabric and your skin. For runners who regularly experience inner-thigh chafing, this construction can be transformative.

Socks and underwear

Feet deserve the same consideration as the rest of the body. A quality running sock in a technical fabric reduces moisture and friction at the same time. HILLY Twin Skin socks apply the same double-layer principle to the foot — the two layers move against each other rather than against your skin, dramatically reducing the friction that causes blisters and toe chafing.

For underwear, seamless or flat-seam options in technical fabrics are worth seeking out for longer distances. The same moisture-wicking logic applies: cotton underwear under running shorts will hold sweat against the skin and contribute to chafing.

Shield your sensitive areas

Anti-chafe balms, sticks, and creams create a physical barrier between skin surfaces or between skin and fabric, reducing the friction that causes damage. There are several formats available:

• Balm sticks (similar to a deodorant stick format) are the most convenient to apply and carry. Products like Body Glide or Squirrel's Nut Butter are popular in the running community.

• Petroleum jelly (Vaseline) is the most widely available and inexpensive option. It works well for shorter distances but can break down over very long efforts as sweat builds up.

• Zinc oxide cream is thicker and longer-lasting than petroleum jelly, making it a better choice for marathons and ultras where protection needs to last for several hours.

Apply balm to all known hot spots before you run — not just the places that have caused problems before, but anywhere you know friction is likely. Inner thighs, underarms, nipples (use dedicated nipple guards or tape for long races), between the toes, and across any area where your waistband or pack sits.

The key mistake runners make is not applying enough. A thin smear will last a fraction of the distance of a properly generous application. Reapplication during a race is possible but difficult — starting with enough protection is the better strategy.

Keep your skin moisturised

Well-moisturised skin is more resilient to friction than dry skin. As a general habit, regularly moisturising the areas prone to chafing — particularly inner thighs and feet — helps maintain the skin's integrity and makes it more resistant to breakdown over long distances.

This is particularly relevant for runners who train in cold or dry conditions, where skin can become dehydrated and cracked, and therefore more vulnerable. Apply a good moisturiser in the evenings after showering in the days before a long race.

Stay hydrated

Hydration plays a less obvious but real role in chafing prevention. When you are well-hydrated, your sweat composition is more dilute. Dehydrated runners produce sweat with a higher salt concentration, and as that sweat dries on the skin during a run, the salt crystals it leaves behind act as additional abrasives — intensifying friction at all the usual hot spots. Staying properly hydrated throughout training and racing therefore reduces one of the compounding factors that turns mild irritation into serious chafing.

How to treat chafing after it's happened

Even with good prevention habits, chafing can still occur — particularly in unexpected conditions or on longer efforts than you've trained for. Here's how to treat it when it does.

Clean and dry the area

Rinse the affected area gently with clean, lukewarm water as soon as possible after your run. Avoid soap on open or broken skin, which will sting and may delay healing. Pat dry carefully — do not rub — and allow the area to air if possible.

Apply a healing or barrier cream

Once clean and dry, apply a healing cream or ointment to the affected area. Sudocrem, zinc oxide cream, or a specialist healing balm will protect the skin, reduce inflammation, and support recovery. Avoid anything containing alcohol or fragrance, which will irritate already-compromised skin.

Rest before running again

This is the part most runners get wrong. Running on chafed skin before it has healed will reopen the damage within the first mile, extend recovery time significantly, and risk infection on broken skin. Allow at least a day or two of rest — or until the skin feels comfortably healed — before resuming running on the affected area. If you do run before full healing, apply a generous barrier layer of zinc oxide cream or a wound-covering dressing to protect the area.

When should I see a doctor about chafing?

Most chafing is a nuisance rather than a medical concern, and heals within a few days with basic care. However, there are situations where it is worth seeking medical advice:

• The skin appears infected — signs include increasing redness beyond the chafed area, swelling, warmth, pus, or a fever.

• The chafing has not improved after several days of rest and basic treatment.

• The wound is deep, bleeding significantly, or showing signs of tissue damage beyond surface abrasion.

• You experience repeated, severe chafing in the same location despite prevention measures — this may indicate an underlying skin condition worth having assessed.

Avoid chafing by running smart and staying comfortable

Chafing is not an inevitable part of running — it is a problem with clear causes and equally clear solutions. The foundations are straightforward: wear technical fabrics that manage moisture, choose well-fitting kit that doesn't move unnecessarily against your skin, apply barrier products to your hot spots before you run, and stay hydrated throughout. For most runners, tackling just one or two of these factors will be enough to eliminate chafing entirely.

For longer distances — half marathons, marathons, and ultras — the combined approach matters more. Consider twin-skin construction for both shorts and socks, apply a longer-lasting barrier product, and reapply if you have access to your kit at a support point.

Running should be about the miles, not what's happening at your inner thighs. Get the kit and the habits right, and it can stay that way.

Browse men's running shorts and women's running shorts — including twin-skin styles — or explore the full HILLY sock range to find the kit that works for your running.

FAQs

Does chafing get worse in warmer weather?

Yes. Heat increases sweating, and moisture is one of the primary drivers of chafing — it softens the skin and increases friction. Warmer weather also means more exposed skin, which can increase skin-on-skin contact at areas like the inner thighs. The combination of heat, sweat, and longer summer runs is when most runners first encounter chafing as a serious problem. In warm conditions, apply barrier products more generously than you would in cooler weather, and consider a longer-lasting formula such as zinc oxide cream rather than petroleum jelly.

Can dehydration make chafing worse?

Yes. Dehydrated runners produce sweat with a higher concentration of salt and other minerals. As this sweat evaporates during a run, it leaves salt deposits on the skin. These deposits act as fine abrasives, intensifying friction at all the usual chafing hot spots. Staying well-hydrated throughout training and racing therefore serves double duty: it keeps your performance up and keeps your sweat composition more dilute, which reduces one of the compounding factors behind chafing.

Should you stop running if you start to chafe in the middle of a run?

It depends on how severe it is. Mild irritation or redness can often be managed by applying an emergency barrier layer — many runners carry a small anti-chafe stick or a sachet of petroleum jelly for exactly this situation. If chafing has progressed to broken or bleeding skin, continuing to run will worsen the damage and significantly extend recovery time. In a race context, this is a judgement call that only you can make — but running through broken skin and then facing a week of recovery is rarely worth it. If you are in training rather than a race, stopping and attending to the affected area is the sensible choice.

How can I prevent inner thigh chafing?

Inner thigh chafing is the most common form for runners, particularly those whose thighs make contact during their stride. The most effective preventions are: wearing twin-skin or well-fitting running shorts that extend to mid-thigh; applying a generous layer of anti-chafe balm to the inner thigh before running; and keeping the area well-moisturised in the days before long efforts. Compression shorts or tights — worn under looser shorts if preferred — provide a close-fitting barrier that eliminates skin-on-skin friction entirely. In warm weather, where sweat increases quickly, a thicker barrier product (zinc oxide cream rather than Vaseline) will last longer.

Can you run with chafing?

You can, but you should take precautions. Apply a thick barrier cream or dressing to the affected area before running, and monitor carefully during the run. Running on mildly irritated but intact skin is unlikely to cause lasting damage if protected. Running on broken, raw, or infected skin risks deepening the wound, extending healing time considerably, and in rare cases causing infection. If the chafed area is open or bleeding, rest until the skin has at least a surface layer of healing tissue before running again — and always seek medical advice if there are signs of infection.