Explore whether runners require more carbohydrates or protein to enhance performance and recovery during training and races.
Do Runners Require More Carbohydrates or Protein?
Runners burn through fuel at rates that sedentary people never have to think about. A long training block or a race weekend forces the body to pull from its stored energy, rebuild damaged muscle fibres, and prepare for the next session. The question of carbohydrates versus protein comes up often because both play distinct roles in this process, and getting the balance wrong affects performance and recovery in measurable ways.
The short answer is that carbohydrate needs exceed protein needs by a wide margin for most runners. But the ratio changes based on training load, race distance, and timing within a training cycle. The body stores carbohydrates as glycogen in muscles and the liver, and these reserves deplete during runs lasting longer than 60 to 90 minutes. Protein, by contrast, supports muscle repair and adaptation but contributes little to immediate energy production during aerobic exercise.
Understanding the numbers behind each macronutrient helps runners make better decisions about meal planning and race-day fueling.
What the Research Says About Carbohydrate Intake
Major sports nutrition organizations have published position statements on this topic. The American College of Sports Medicine, the International Society of Sports Nutrition, and the International Olympic Committee all agree on a range of intakes based on activity level.
For runners doing light training, the recommendation sits at 3 to 5 g of carbohydrates per kilogram of body weight per day. A 70 kg runner at this level would aim for 210 to 350 g daily. Moderate training bumps this up, and runners doing high-volume or high-intensity work need 8 to 12 g/kg/day. That same 70 kg runner would then require 560 to 840 g of carbohydrates daily to maximize glycogen stores.
These numbers surprise many recreational runners who underestimate how much fuel endurance training demands.
Mid-Race Fueling and the Carbohydrate Gap
A 2024/2025 study published in Sports Medicine-Open found that runners who consumed 60–90 g of carbohydrates per hour during competition were more likely to finish a marathon under 180 minutes. The average intake among participants, however, sat at 35 ± 17 g/h. This gap between recommendation and practice points to a fueling problem that affects finish times.
Portable carbohydrate sources help runners close that gap. Options include bananas, dried fruit, chews, and the best energy gels for running. Each delivers fast-absorbing sugars in forms that are easier to consume mid-stride than solid food. Single-source carbohydrates oxidize at roughly 60 g/h, which sets a practical ceiling for most races lasting two to three hours.
Protein Requirements for Runners
The same organizations recommend 1.2 to 2.0 g of protein per kilogram of body weight per day for athletes. A 70 kg runner falls into a range of 84 to 140 g daily. This is higher than the general population recommendation of 0.8 g/kg/day, but it remains lower in absolute terms than carbohydrate needs for most training scenarios.
Protein timing matters more than total daily intake in some respects. Research suggests that consuming 20 to 40 g of protein every 3 to 4 hours produces better outcomes for muscle protein synthesis than eating the same total amount in one or two large meals. A runner who eats 30 g of protein at breakfast, lunch, dinner, and a late snack distributes intake more effectively than one who eats 120 g at dinner alone.
When Recovery Demands Both
The period immediately after a hard run or race creates a window where both macronutrients matter. Muscle glycogen is depleted and muscle fibers have sustained micro-damage from repetitive contractions. The body needs carbohydrates to refill glycogen stores and protein to begin the repair process.
Research supports combining carbohydrates at 0.8 g/kg/h with protein at 0.2 to 0.4 g/kg/h when rapid glycogen restoration is needed. For a 70 kg runner, this means roughly 56 g of carbohydrates and 14 to 28 g of protein in the first hour after finishing. A meal containing rice, chicken, and vegetables hits these targets reasonably well. So does a smoothie with fruit, yogurt, and a scoop of protein powder.
Ultra-Endurance Running Changes the Math
Events lasting longer than 3 hours push carbohydrate recommendations higher. Ultra-endurance athletes may need up to 90 g of carbohydrates per hour during competition. This rate exceeds what the gut can absorb from a single carbohydrate source, so athletes training for ultras often practice with multiple transportable carbohydrates, typically glucose and fructose in combination.
Protein needs during ultra events remain a topic of ongoing research. Some runners consume small amounts of protein during races lasting 6 hours or more, but the primary fuel source remains carbohydrates.
Practical Considerations for Meal Planning
Runners who struggle to eat enough carbohydrates often rely too heavily on vegetables and lean proteins. These foods fill the stomach without providing enough glycogen-replenishing fuel. Adding rice, potatoes, bread, oats, and fruit increases carbohydrate intake without requiring dramatic changes to eating patterns.
Protein intake is easier to meet for most runners who eat a varied diet. Eggs, dairy, meat, fish, legumes, and tofu all contribute to daily totals. Runners following plant-based diets may need to pay closer attention to protein sources and combine foods to get complete amino acid profiles.
The Bottom Line on Ratios
Carbohydrates take priority for runners. The body relies on glycogen during sustained aerobic activity, and depleted stores lead to fatigue, slower paces, and longer recovery times. Protein supports adaptation and repair but does not provide the primary fuel for running.
A runner training 5 to 7 hours per week likely needs 5 to 7 g of carbohydrates per kilogram daily and 1.4 to 1.6 g of protein per kilogram. A runner training 10 to 15 hours per week pushes closer to 8 to 10 g of carbohydrates and 1.6 to 2.0 g of protein. The exact numbers depend on body composition goals, race distance, and training phase.
Getting both macronutrients right matters. But for most runners, carbohydrates remain the limiting factor in performance and recovery.
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