Nutrition
Even small fluid deficits can affect endurance performance, but thirst is still a useful safety cue—drinking far beyond thirst can be dangerous.
Why it matters: Heat illness risk rises when heat production exceeds heat loss, especially on long, hot stages; over-drinking may also increase the risk of exercise-associated hyponatraemia.
Dr Green’s tip: Start well hydrated, drink to thirst, and use planned access points to top up according to heat, pace, sweat rate and stage duration—not by forcing fluid every few minutes.
Did you know?
Clear urine does not always mean you are safely hydrated during or after a race.
Why it matters: Over-drinking can dilute blood sodium and cause exercise-associated hyponatraemia, which may present with headache, nausea, vomiting, swelling, confusion, seizures or collapse.
Dr Green’s tip: Drink to thirst and include sodium-containing food or electrolyte fluids during long, hot stages. After each stage, monitor urine output; seek medical help if you pass little or no urine for around 2 hours despite sensible drinking, or if you feel increasingly unwell.
Did you know?
Heat exhaustion can affect even experienced riders, especially when fatigue, inadequate recovery and high heat load accumulate over several days.
Signs to watch for: Dizziness, nausea, headache, weakness, heavy sweating, chills, cramps, poor coordination or visual disturbance—while still thinking clearly.
Dr Green’s tip: Stop early, move to shade, remove excess kit, start active cooling with water/ice towels/fanning, and drink according to thirst. Do not continue if symptoms are worsening or if mental status changes develop.
Did you know?
Exertional heat stroke is a medical emergency—not simply “bad heat exhaustion.”
Red flags: Confusion, disorientation, collapse, seizures, loss of consciousness, irrational behaviour or loss of coordination, with suspected high core temperature.
Dr Green’s tip: Activate emergency medical support immediately and start rapid cooling on scene. The priority is “cool first, transport second” where safe and supervised: cold-water or ice-water immersion is best; if unavailable, use continuous water dousing, ice towels, fanning and ice packs to the neck, armpits and groin. Do not give oral fluids to anyone confused, drowsy, vomiting or unable to swallow safely.
Did you know?
Sweat contains water and electrolytes—mostly sodium—but sweat sodium losses vary widely between riders.
Why it matters: Sodium replacement can help maintain fluid balance during long stages, but sodium tablets do not “prevent” heat stroke and should not be used to justify over-drinking.
Dr Green’s tip: Use familiar electrolyte drinks or salty foods during prolonged hot stages, guided by thirst, expected sweat loss, gut tolerance and previous training experience.
Did you know?
Muscle cramps are not caused by dehydration alone.
Why it matters: Exercise-associated cramps are often linked to neuromuscular fatigue, pacing, conditioning and previous cramp history; dehydration or sodium imbalance may contribute in some riders but are not the full explanation.
Dr Green’s tip: Prevent cramps with sensible pacing, heat acclimatisation, adequate fuelling, strength/endurance preparation and individualised fluid-electrolyte strategies—not water alone.
Did you know?
Starting too hard in the heat can raise core temperature early and increase risk later in the stage.
Why it matters: Heat strain is driven by exercise intensity, environment, clothing, terrain, hydration status and recovery from previous days.
Dr Green’s tip: Begin conservatively, adjust effort to heat and humidity, use shade and cooling opportunities, and reduce pace before symptoms appear—especially during the first 48–72 hours and on hotter stages.
Did you know?
The brain is often the clearest warning sign in serious heat illness.
Early signs: Poor decision-making, unusual behaviour, confusion, irritability, clumsiness, slowed reactions or not following instructions.
Dr Green’s tip: If you or your partner are making unusual mistakes, riding erratically or seeming “not yourself,” stop immediately, cool aggressively and call the medical team.
Did you know?
Ignoring early heat symptoms is a common reason athletes deteriorate and need evacuation.
Why it matters: Heat illness can progress quickly, and outcomes are best when cooling starts early—ideally before collapse or neurological symptoms occur.
Dr Green’s tip: Use the buddy system: check each other’s behaviour, speech, coordination and pace. Stop early, cool early and ask for help early.
Did you know?
Mediclinic and ER24 teams are there to support—not to end your race unnecessarily.
Reassurance: Early medical review can often keep a manageable issue from becoming a race-ending emergency.
Dr Green’s tip: Report early symptoms honestly. Medical teams can assess cooling needs, hydration status, sodium risk, kidney concerns, recovery readiness and whether it is safe to continue in a 7-day event.
Did you know?
Heat stress is cumulative across a 7-day multistage event.
Why it matters: Sleep debt, muscle damage, poor appetite, gastrointestinal upsedehydration, inadequate sodium intake and incomplete cooling can all reduce heat tolerance the next day.
Dr Green’s tip: Treat recovery as part of race safety: cool down immediately after each stage, replace fluids and sodium through normal meals and drinks, eat carbohydrate and protein, monitor urine output and daily wellbeing, and speak to the medical team before the next stage if symptoms persist.