Pre-Workout Nutrition for Endurance Athletes: A Periodised Approach
From fasted easy sessions to race-day carb loading, learn how to fuel each training block for maximum adaptation and minimum gastrointestinal distress.
Dr. Rohan Thapa
Periodisation: matching fuel to the training block
Endurance nutrition is not one-size-fits-all. A marathoner in base-building phase needs different fueling than the same athlete in taper week or race week. Periodised nutrition matches carbohydrate availability to training load: high-carb days on hard session days, low-carb days on easy days, and strategic 'train low' sessions to stimulate mitochondrial adaptation. This 'fuel for the work required' model, pioneered by researchers like James Morton at Liverpool John Moores University, has become the gold standard for elite endurance fueling.
Pre-workout: less is more for easy sessions
For easy aerobic sessions under 75 minutes, you don't need pre-workout carbs — in fact, training in a fasted or low-glycogen state can stimulate adaptations. For sessions over 90 minutes or any high-intensity work, however, pre-fueling matters. A simple rule of thumb: 1g of carbohydrate per kg of body weight, 1–3 hours before. For a 65kg runner, that's a bowl of oats with banana and honey, eaten 2 hours before. Avoid high-fibre and high-fat foods in the 90 minutes before hard efforts — they slow gastric emptying and can cause distress.
Race-day fueling: the 60-90g/hour rule
For events lasting longer than 2 hours, aim for 60–90g of carbohydrate per hour — a threshold supported by decades of sports science. This is more than most amateurs consume, and it requires gut training (practicing fueling in long sessions) to tolerate. Use multiple transportable carbohydrates (glucose + fructose in a 2:1 ratio) to exceed the 60g/hour single-source limit. For a marathon, that means 2–3 gels per hour plus sports drink, practiced religiously in the final 6 weeks of training. Never try anything new on race day.
Recovery: the 30-minute window, demystified
The 'anabolic window' is less narrow than once believed, but post-session nutrition still matters — especially after hard or long sessions. Aim for 0.3g protein per kg body weight within 2 hours, plus 1–1.2g carbohydrate per kg to begin glycogen replenishment. For a 65kg athlete: 20g protein and 65g carbs — a chicken sandwich and a banana, or a recovery shake and a bowl of cereal. Hydration matters too: replace 1.5x the fluid lost (weigh yourself pre/post to estimate), with electrolytes for sessions over 90 minutes or in heat.
About the author
Dr. Rohan Thapa
Dr. Rohan Thapa leads Sports Nutrition at The Dietitian's Clinic. He is a former national team nutritionist with 11 years of elite-athlete experience.