Fuelling the Trail: Nutrition and Hydration for Hikers

Nutrition for hiking is simpler than sports nutrition for high-intensity athletics, but it is not trivial. The primary goals are: maintaining blood glucose levels to sustain energy and cognitive function; replacing fluid and electrolytes lost through sweat; and providing the macronutrients needed for muscle repair and recovery after the hike. Getting these basics right makes the difference between a hike that feels effortless and one that ends in fatigue, cramping, or hypoglycaemia.

Pre-hike nutrition. The meal before a hike should be consumed 1.5–3 hours beforehand and should emphasise complex carbohydrates for sustained energy, moderate protein for muscle support, and low fat and fibre to minimise gastrointestinal discomfort on the trail. Good pre-hike meals include oatmeal with banana and nut butter, whole grain toast with eggs and avocado, or a Greek yogurt bowl with berries and granola. Avoid high-fat, high-fibre meals immediately before strenuous activity — they slow gastric emptying and can cause nausea or cramping.

On-trail fuelling: the 45-minute rule. For hikes lasting more than 90 minutes, regular fuelling is important to maintain blood glucose and delay fatigue. The general guideline is to consume 30–60g of carbohydrates per hour of sustained activity. In practice, this means eating a small snack every 45–60 minutes. Ideal trail snacks are calorie-dense, lightweight, and require no preparation: trail mix (nuts, dried fruit, seeds), energy bars, bananas, dates, rice cakes, or whole grain crackers with nut butter. Avoid relying on sugary sweets alone — they cause rapid blood glucose spikes followed by crashes.

Hydration strategy. Dehydration of just 2% of body weight impairs aerobic performance by 10–20% and significantly reduces cognitive function. For a 70kg hiker, that is just 1.4 litres of fluid loss — achievable in under two hours of moderate hiking in warm weather. The practical hydration strategy is: drink 500ml of water in the hour before the hike; carry at least 500ml per hour of planned hiking time (more in heat); drink before you feel thirsty (thirst is a lagging indicator of dehydration); and include electrolytes on hikes longer than 2 hours or in hot conditions. Electrolyte tablets, coconut water, or salty snacks help replace sodium, potassium, and magnesium lost in sweat.

Electrolytes and hyponatraemia. Hyponatraemia — dangerously low blood sodium — is a real risk for hikers who drink large amounts of plain water without replacing sodium. It is more common in endurance events but can occur on long hot-weather hikes. Symptoms include nausea, headache, confusion, and in severe cases, seizures. Prevention involves consuming salty snacks alongside water, using electrolyte supplements on long hikes, and not drinking excessively beyond thirst. Sports drinks or electrolyte tablets are appropriate for hikes exceeding 3 hours in warm conditions.

Post-hike recovery nutrition. The 30–60 minutes after a hike is the optimal window for recovery nutrition. Consuming a combination of carbohydrates (to replenish glycogen stores) and protein (to initiate muscle repair) during this window accelerates recovery and reduces next-day soreness. A ratio of approximately 3:1 carbohydrates to protein is well-supported by the sports nutrition literature. Practical options include a smoothie with banana, Greek yogurt, and berries; chocolate milk (a surprisingly well-researched recovery drink); or a meal of rice, grilled chicken, and vegetables. Rehydration should continue after the hike — aim to replace 150% of fluid lost (weigh yourself before and after if precision matters).