How Runners Can Prevent Fatigue Through Nutrition

Group of runners training

Feeling burnt out and extra tired when you exercise frequently or in high intensities is very common – especially when you participate in physical activity that requires a lot of endurance (such as long distance running). You may feel like your mile times are slowly increasing, your pace decreasing, you’re getting fatigued faster than usual, or you can not run as much distance as you have been able to in the past. One of many reasons could be because you have burnt yourself out. So, what are you going to do about it?

Nutrition is important to runners, just like any other endurance athlete. Nowadays, the intensity has increased with many people not only participating in the standard 5k races, half marathons, or marathons – but also – some  races will include physically demanding obstacles or challenges, such as tough mudders or iron man races.(1) These types of races can take a lot of energy and even last for several hours or days; not to mention the increased training needed before race day. When preparing for these races or training in high intensities, it is of utmost importance that you have proper nutrition to fuel yourself through the workout.

While carbohydrates are known to be of high importance, some discussion is needed about “carb loading” and if it is important for athletes exercising in high intensities or endurance training. First, it is important to acknowledge that carbohydrates are the number one energy source for your brain and they are an absolute must for any athlete to consume. Although, the amount of carbohydrates needed for certain intensities vary. If you are participating in about an hour of moderate exercise each day then 5 to 7 grams per kilogram of body fat per day (g/kg/day) is an adequate amount of carbohydrates to fuel your body. If you are participating in roughly one to three hours of moderate to high intensity exercise each day then 6 to 10 g/kg/day of carbohydrates is appropriate. Lastly, if you are consistently participating in four to five hours of high intensity training each day then you should consume up to 8 to 12 g/kg/day of carbohydrates.(2) By consuming the appropriate amount of carbohydrates for your workouts will help to maximize your glycogen stores.(3)  The nutritional strategy of “carb loading” is executed a few days or up to a week prior to race day to maximize the storage of glycogen in the muscles and liver. While this strategy may be helpful for race day, it is best to meet with a registered dietitian to ensure your customized strategy is optimal for peak performance and not hindering your outcomes. 

With so much discussion about carbohydrates, other macronutrients often are overlooked by endurance athletes. Protein needs are often underemphasized because there is so much emphasis on consuming high levels of carbohydrates for endurance athletes.(4) Typically, consuming more than the recommended amount of protein each day does not show many benefits if you are endurance training. An exception would be temporarily elevating protein above the recommended level of 2 grams per kilogram of body weight during periods of increased strength training. Adequate protein intake should be 0.3 g/kg every three to five hours dosed throughout the day for a total of 1.2 to 2 g/kg/day.(2) Looking for that competitive edge? When pairing your protein source with a carbohydrate source post exercise, you can increase muscle glycogen synthesis by 40-100%.(5)

The third macronutrient, fat, is also often overlooked when discussing nutritional intakes for training athletes. Recommendations for fat consumption do not differ much from the typical standardized guidelines you may be more familiar with. Many athletes have become interested in the “high fat, low carb” approach, however, this is not recommended if you have a goal to improve your overall performance.(2,6,7) Fat intake should only be reduced if you are “carb loading” before a race.(2) 

If you catch yourself feeling fatigue and notice a reduced performance while training, we highly recommend you meet with a qualified professional – such as a registered dietitian. These professionals can help you customize a specific meal structure and plan of action to ensure you achieve your training needs and help reach your peak performance potential.  Recommendations and scientific research for endurance nutrition is always updating!  Thus, please do not be afraid to ask your care team when you need clarification or have goals you want to reach and need guidance via nutrition! 




  1. Miller J.A. The Running Bubble Has Popped. (You Couldn’t Hear It in New York.)—The New York Times. [(accessed on 2 April 2019)]; Available online:
  2. Jäger R., Kerksick C.M., Campbell B.I., Cribb P.J., Wells S.D., Skwiat T.M., Purpura M., Ziegenfuss T.N., Ferrando A.A., Arent S.M., et al. International Society of Sports Nutrition Position Stand: Protein and Exercise. J. Int. Soc. Sports Nutr. 2017;14:20. doi: 10.1186/s12970-017-0177-8.
  3. Thomas D.T., Erdman K.A., Burke L.M. Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and Athletic Performance. J. Acad. Nutr. Diet. 2016;116:501–528. doi: 10.1016/j.jand.2015.12.006.
  4. Phillips S.M., Van Loon L.J.C. Dietary Protein for Athletes: From Requirements to Optimum Adaptation. J. Sports Sci. 2011;29(Suppl. 1):S29–S38. doi: 10.1080/02640414.2011.619204.
  5. Jeukendrup A.E., Jentjens R.L.P.G., Moseley L. Nutritional Considerations in Triathlon. Sports Med. 2005;35:163–181. doi: 10.2165/00007256-200535020-00005.
  6. Getzin A.R., Milner C., Harkins M. Fueling the Triathlete: Evidence-Based Practical Advice for Athletes of All Levels. Curr. Sports Med. Rep. 2017;16:240–246. doi: 10.1249/JSR.0000000000000386.
  7. Getzin A.R., Milner C., LaFace K.M. Nutrition Update for the Ultraendurance Athlete. Curr. Sports Med. Rep. 2011;10:330–339. doi: 10.1249/JSR.0b013e318237fcdf.

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