If you want to improve performance or even just support a healthy, consistent running routine, nutrition matters. Not in a vague “eat clean” way, but in a practical “did you actually fuel the work you are asking your body to do?” way.
At a basic level, your daily diet is built on three macronutrients. A useful guideline for the percentage of total daily calories is:
If you eat a diverse whole-food diet, you will usually cover your micronutrients too, and those are critical for muscle function, recovery, and overall health. Let’s break it down.
Carbs are your friend. And most runners are not eating enough of them.
Adequate carbohydrate intake helps you maximize glycogen stores, maintain energy for training and recovery, and fuel the brain and central nervous system. When carbohydrate stores are low, fatigue rises, output drops, and concentration suffers. That is why fueling before, during, and after training matters (Thomas et al., 2016).
Daily carbohydrate intake should generally fall between 50%-65% of total calories, depending on training volume (Aragon et al., 2017).
As a guideline:
Most recreational runners will not hit those higher training volumes, but the point stands. If you are training hard and feeling flat, carbs are one of the first things to check.
Fat is a key energy source, especially for ultrarunners who have high energy demands.
Dietary fat supports:
It also supports the absorption of fat-soluble vitamins A, D, E, and K, which makes it an essential part of a runner’s diet (Stellingwerff et al., 2019; Thomas et al., 2016; Vitale & Getzin, 2019).
If you restrict fat intake to less than 20% of total energy, you increase the risk of low essential fatty acid intake such as omega-3, poor absorption of fat-soluble vitamins, and low energy availability (Thomas et al., 2016).
For runners, a good target is 20-30% of total daily energy intake.
Running breaks muscle down. Protein is what helps you rebuild it.
Without adequate protein, muscles do not rebuild efficiently, which can contribute to muscle wasting, higher injury risk, and poorer performance (Campbell et al., 2007; Cintineo et al., 2018).
Protein supports:
For optimal performance, runners typically need 1.2-2g/kg/day, with higher needs at higher training volumes (Thomas et al., 2016).
Ultra trail racing can produce significant muscle damage due to the vertical load and eccentric contractions. In these cases, taking in protein at 0.25g/kg/hr along with carbohydrate (90g/hr) during exercise can support performance. After running, muscle protein synthesis is maximized when amino acids are available, so timing matters. A strong guideline is 0.3g/kg of quality protein within 1 hour post-exercise to maximally stimulate muscle protein synthesis and support recovery (Vitale & Getzin, 2019).
Micronutrient needs vary between athletes, but a few deserve special attention (Thomas et al., 2016):
If you suspect a deficiency or want to start supplementing, speak with a healthcare professional.
The major electrolytes in the body are:
Electrolytes regulate body fluids, help maintain blood pH, and create electrical impulses essential for physical activity, from basic cell function to complex neuromuscular work.
After around three hours of exercise, many athletes notice a performance decline if electrolytes are not being replaced. In the hour after exercise, aim to replenish electrolytes with 500-700mg of sodium and enough water to replace 1.5 times the amount lost during exercise.
After training, there is a window where muscle cells are primed to replenish glycogen (Richter et al., 2001). While this window remains open for many hours, it is generally best to start replenishing within 30-60 minutes after finishing the session (Burke et al., 2017).
A useful guideline is:
For recovery, a 4:1 ratio of carbohydrate to protein is often recommended. This ratio has been shown to reduce post-exercise muscle damage by 36 percent (Ivy, 2004). Many companies sell recovery powders and drinks built around this ratio, but you can also achieve it with normal food if you plan it.
Aragon, A.A. et al. (2017) “International Society of Sports Nutrition Position Stand: Diets and body composition,” Journal of the International Society of Sports Nutrition, 14(1). Available at: https://doi.org/10.1186/s12970-017-0174-y.
Burke, L.M. et al. (2011) “Carbohydrates for training and competition,” Journal of Sports Sciences, 29(sup1). Available at: https://doi.org/10.1080/02640414.2011.585473.
Burke, L.M., van Loon, L.J. and Hawley, J.A. (2017) “Postexercise muscle glycogen resynthesis in humans,” Journal of Applied Physiology, 122(5), pp. 1055–1067. Available at: https://doi.org/10.1152/japplphysiol.00860.2016.
Campbell, B. et al. (2007) “International Society of Sports Nutrition Position Stand: Protein and exercise,” Journal of the International Society of Sports Nutrition, 4(1). Available at: https://doi.org/10.1186/1550-2783-4-8.
Cintineo, H.P. et al. (2018) “Effects of protein supplementation on performance and recovery in resistance and endurance training,” Frontiers in Nutrition, 5. Available at: https://doi.org/10.3389/fnut.2018.00083.
Ivy, J.L. (2004) “Regulation of Muscle Glycogen Repletion, Muscle Protein Synthesis and Repair Following Exercise,” J Sports Sci Medicine, 3, pp. 131–138.
Richter, E.A., Derave, W. and Wojtaszewski, J.F. (2001) “Glucose, exercise and insulin: Emerging concepts,” The Journal of Physiology, 535(2), pp. 313–322. Available at: https://doi.org/10.1111/j.1469-7793.2001.t01-2-00313.x.
Stellingwerff, T., Bovim, I.M. and Whitfield, J. (2019) “Contemporary nutrition interventions to optimize performance in middle-distance runners,” International Journal of Sport Nutrition and Exercise Metabolism, 29(2), pp. 106–116. Available at: https://doi.org/10.1123/ijsnem.2018-0241.
Thomas, D.T., Erdman, K.A. and Burke, L.M. (2016) “Position of the Academy of Nutrition and Dietetics, dietitians of Canada, and the American College of Sports Medicine: Nutrition and Athletic Performance,” Journal of the Academy of Nutrition and Dietetics, 116(3), pp. 501–528. Available at: https://doi.org/10.1016/j.jand.2015.12.006.
Vitale, K. and Getzin, A. (2019) “Nutrition and supplement update for the endurance athlete: Review and recommendations,” Nutrients, 11(6), p. 1289. Available at: https://doi.org/10.3390/nu11061289.
