Cardiff Half Marathon

Keeping Safe While You Run

Completing a mass participation race is a huge achievement. Follow these tips to cross the finish line safe, strong, and smiling.

Advice from Dr Katy Guy, MBBCh, FRCEM, DFSEM (U.K.) Dip SEM, a Consultant in Emergency Medicine in Swansea and Medical Director of the Oysho Cardiff Half Marathon.

Katy works with a variety of sports and has been CMO for Team Wales at Commonwealth Games and is an accredited race medical director through World Athletics.

βœ… Before the Race

πŸ’‘ Are You Fit to Run?

  • Check with your GP or specialist if you have a medical condition.
  • Seek medical advice if you have:
    • Family history of heart disease or sudden cardiac death
    • High cholesterol or high blood pressure
    • Symptoms such as chest pain, palpitations, or breathlessness

⚠️ Don’t ignore warning signs β€” running with unresolved symptoms can be dangerous.

⏱ Don’t Chase the Clock

  • Listen to your body, not your watch.
  • If you feel dizzy, faint, or unwell β€” slow down or stop.
  • On hot days, accept a slower pace β€” overheating can lead to heat stroke.

πŸ₯ Race Day Readiness

  • Feeling unwell? Don’t run.
    • Diarrhoea/vomiting = dehydration risk
    • Recent viral illness = risk of heart inflammation
  • Bring your medication (e.g., inhaler if asthmatic).
  • Dress smart:
    • Lightweight, breathable kit (avoid cotton)
    • A visor is cooler than a hat
    • Pour water over yourself if overheating

🏷 Mark Your Bib

  • Write any medical conditions on the back.
  • Add up-to-date emergency contact details.
  • ❌ Don’t swap numbers β€” it risks contacting the wrong person in an emergency.

πŸ’§ Hydration & Fuelling

  • Drink to thirst, not to a fixed schedule.
  • Alternate water with electrolyte drinks.
  • Try an electrolyte slushy (frozen sports drink) 10–20 minutes before the race β€” proven to lower core body temperature by ~2Β°C.
  • After the race: rehydrate with electrolytes and salty snacks.

🏁 At the Finish Line

  • ❌ Don’t stop immediately after a sprint.
  • βœ… Keep walking to prevent a sudden drop in blood pressure.
  • Medals and water are placed further away deliberately β€” to keep you moving safely.
  • Our medical team may remind you to keep walking β€” not to be unkind, but to protect you.

🩺 After the Race: Common Issues

πŸ”₯ Heat Stroke

⚠️ Avoid ibuprofen, diclofenac, Voltaren, or NSAIDs for 48 hours β€” they can harm your kidneys.
βœ… Visit your GP within a week for blood tests if you had heat exhaustion.
❌ No sport for 2–4 weeks after heat stroke.
πŸ” Risk of recurrence β€” ask about heat tolerance testing.

🀒 Persistent Vomiting

  • Sip fluids slowly.
  • Snack lightly until nausea passes.

🍬 Hypoglycaemia (Low Blood Sugar)

  • Can occur if you don’t refuel properly.
  • Start glucose intake after ~8 miles (gels/chews).
  • Severe cramps may also be linked to low sugar, not just dehydration.
  • Review your fuelling plan before your next event.

πŸ§‚ Hyponatraemia (Low Sodium)

  • Caused by overhydration.
  • Drink only when thirsty.
  • Add salty snacks post-race.

πŸ‘Ÿ Sprains, Strains & Blisters

  • Break in trainers before race day.
  • Use plasters or tape to protect vulnerable skin.

❀️ Pre-Existing Medical Conditions

  • Always check with your doctor before racing.
  • Let organisers know of any relevant conditions.

🚨 Cardiac Arrest (Rare)

  • Seek urgent medical advice if you experience:
    • Chest pain
    • Dizziness
    • Collapse during exercise
  • If a family member suffered sudden cardiac death before age 35, ask your GP about screening.

πŸŽ‰ Final Word

Crossing the finish line is an incredible achievement. Take care of yourself, listen to your body, and celebrate your success safely.

πŸ‘‰ more medical and safety advice here.

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