How to Prevent and Treat Blisters in Triathlon Training and Racing

Why Triathletes Get Blisters More Than Other Athletes

Triathlon has a unique combination of blister risk factors: a swim exit leaves feet wet, transition means pulling socks and shoes on over damp skin, race-day adrenaline masks early hot-spot pain until it’s already a problem, and plenty of athletes end up racing in shoes or socks they haven’t fully broken in.

Prevention Starts in Training

• Break in race shoes over several long runs before race day — never race in shoes straight out of the box.
• Test your full race-day sock-and-shoe combination in training, including running on wet feet straight after a swim or shower to simulate T1 conditions.
• Apply an anti-friction balm to known hot spots — heels, between toes, ball of the foot — before long runs and on race day. The same anti-chafe products covered in our anti-chafe and chamois cream guide work well here too.
• Trim toenails a few days before race day, not the morning of, so any soreness has time to settle.

Race-Day Tactics

• Pre-tape or apply a hydrocolloid plaster to any spot that’s blistered before, even if it feels fine at the start — prevention is far easier than treatment mid-race.
• Dry your feet as best you can in transition. A quick wipe with a small towel in your T1 bag costs a few seconds and meaningfully cuts friction on the run.
• Choose socks — or a sockless setup, if you’ve specifically trained for it — based on what you’ve tested, not on what’s fastest to pull on.

Treating a Blister Mid-Race

If a hot spot develops mid-run, stopping briefly to address it — tape, a sock adjustment, a shoe re-lace — rarely costs more time than the compensating stride pattern that follows if you ignore it and start favouring the other foot. Cover the spot with tape or a plaster if you’re carrying any; otherwise, push on and treat it properly once you’ve finished.

Post-Race Blister Care

• Leave small, unbroken blisters alone — the skin over the top protects against infection while it heals underneath.
• If a blister has already burst, clean the area, apply an antiseptic, and cover with a hydrocolloid dressing rather than a standard plaster.
• Only drain a large, painful blister yourself with a sterilised needle if genuinely necessary, leaving the roof of skin in place, and keep it covered until it dries out.
• See a podiatrist for blisters that keep recurring in the same spot — that’s usually a sign of a shoe, sock or gait issue worth fixing properly rather than repeatedly patching over.