Sayuri Science · Sport & Skin
Chlorinated pool water raises the skin’s pH by about one unit, removes surface oils and increases water loss through the skin barrier; after a single swim, healthy skin needs roughly a day to recover. The best routine is simple: rinse before you swim, protect the skin with a light barrier layer, and afterwards cleanse gently, restore calm with a barrier essence and seal in moisture with a ceramide cream.
By Katerina Trofimova, biochemist, founder of Sayuri and competitive swimmer since childhood · Last updated: November 2026
Why I care about swimmers’ skin
I started competitive swimming at the age of three, within the Olympic preparation system, and I still train in the water today. For most of my life my skin has spent hours a week in chlorinated water. Long before I became a biochemist, I knew the feeling every swimmer knows: tight, dull skin after training, itchy shins, a face that looks tired even when you feel strong. This article is what I wish someone had explained to me back then.
What does pool water do to your skin?
Pool water challenges the skin in three ways at once: its pH, its effect on skin oils and its effect on the barrier.
- It shifts the skin’s pH. Healthy skin is slightly acidic, around pH 5.5, while pool water is kept slightly alkaline, at pH 7.2–7.4, so that chlorine disinfects effectively (National Eczema Society). In a study of recreational swimmers, skin pH rose by about one unit — from around 5.6 to around 6.5 on the upper chest — and skin hydration fell by about 20% on the forearm and 13% on the cheek four hours after swimming (Dheurle et al., 2004).
- It weakens the barrier. In elite swimmers, transepidermal water loss (TEWL) — the measure of how much water escapes through the skin — rose significantly after a two-hour training session, more than in football players training outdoors (Paciência et al., 2021).
- It strips surface oils — but not pore oils. Swimming removes sebum from the skin surface more than from inside the pores, which explains why swimmers can have dry skin and breakouts at the same time (Morss-Walton et al., 2022).
What one swim does to your skin
Sources: Dheurle et al., 2004 (recreational swimming, measured 4 hours after); Paciência et al., 2021 (2-hour training, elite swimmers); National Eczema Society.
The good news: in the recreational-swimming study, healthy skin returned to its baseline within 24 hours. The challenge is that regular swimmers go back into the water before that recovery is complete. Over weeks and months, that is how “swimmer’s skin” develops: chronic dryness, itching, sensitivity and a dull, older-looking complexion.
The Sayuri post-swim routine
Before you swim
- Rinse with fresh water. Skin that is already wet with clean water takes up less pool water.
- Protect. On the face, a thin layer of a rich barrier cream such as Hi-Active Barrier Restore Cream helps shield the skin from direct contact with the water.
After you swim (within 15 minutes)
- Shower lukewarm, not hot. Hot water removes even more lipids.
- Cleanse gently. Use a soap-free cleanser that respects the barrier — OlioGel for dry or mature skin, or Enzyme Cleansing Gel for normal and oily skin. Avoid alkaline soap: it pushes the pH up even further.
- Calm and rehydrate. Press in Hi-Active Barrier Tonic, a barrier essence with probiotic ferments and panthenol, followed by Barrier Code Serum.
- Seal in moisture. Finish with Hi-Active Barrier Restore Cream (rich, with ceramides NP, AP and EOP) or, for a lighter feel, Hi-Active Barrier Reset Cream. Around the eyes, where chlorine often stings, use Barrier Reset Eye Comfort.
On training days, skip the strong actives
Right after swimming the barrier is at its most permeable. Save exfoliating acids, retinoids and peels for evenings when you have not been in the pool, or for days off.
Why magnesium matters for swimmers
Magnesium salts help the skin barrier recover faster after it has been disrupted (Denda et al., 1999). That is one reason I built Sayuri formulas around magnesium from the Zechstein deposits beneath the Netherlands. Read more in Zechstein magnesium in skincare and in the Longevity Axis™.
Frequently asked questions
Should I shower straight after swimming?
Yes. Rinsing off pool water quickly limits how long chlorine and its by-products stay on the skin. Use lukewarm water and a gentle, soap-free cleanser.
Why do I get dry skin and breakouts at the same time after swimming?
Swimming removes oil from the skin surface but much less from inside the pores. The surface becomes dry and tight, while pores can still become congested. Gentle cleansing and barrier care help both.
Does chlorine age the skin?
There are no long-term studies that measure ageing in swimmers. What is documented is repeated barrier stress, dryness and a higher skin pH — all of which make skin look duller and less resilient. Outdoor swimmers also need sun protection, because UV remains the main external driver of skin ageing.
Is sea water better for the skin than pool water?
Sea water contains magnesium and other minerals and no added chlorine, so many people find it kinder to their skin. It is still salty and, outdoors, comes with sun exposure — so rinse, moisturise and use sun protection afterwards.
Can I use retinol after swimming?
It is better not to apply retinoids or exfoliating acids straight after a swim, when the barrier is most vulnerable. Use them on non-swimming evenings.
Sources
- Paciência I, Rodolfo A, Leão L, et al. Effects of exercise on the skin epithelial barrier of young elite athletes — swimming comparatively to non-water sports training session. Int J Environ Res Public Health. 2021;18(2):653. PMC7828688
- Dheurle S, Guéhenneux S, Morizot F, Latreille J, Guinot C, Tschachler E. Variations of skin biophysical properties after recreational swimming. Skin Res Technol. 2004;10(4). Abstract
- Morss-Walton PC, Kimball R, Rosales Santillan M, et al. Effects of swimming on facial sebum in adolescents. Pediatr Dermatol. 2022;39(3):376–378. Abstract
- National Eczema Society. Eczema and swimming factsheet (reviewed November 2024). PDF
- Denda M, et al. Some magnesium salts and a mixture of magnesium and calcium salts accelerate skin barrier recovery. Arch Dermatol Res. 1999;291:560–563. PubMed 10552215
Sayuri products are cosmetics intended to support the appearance and condition of the skin. They are not medicines and do not treat or prevent disease. If you have eczema or persistent irritation after swimming, consult your doctor.
