How to Fuel Your Long Runs
By Holley Samuel MEd, RD, LD, CSSD, CPT
With spring race season upon us, many runners are starting to ramp up their mileage and training to prepare for their next race. Whether that race is a half, full, or ultra marathon and beyond, there will likely be long runs integrated into the training plan each week or so to help runners improve their endurance for this event. If this is your first time at a distance like a half, full, or ultra marathon, learning how to fuel your long runs can be completely overwhelming. If you are experienced in these distances, you may still question if you are fueling your long runs properly to get the most potential out of yourself as a runner. Let’s dive into current fueling recommendations for endurance athletes of all levels so you can fine tune your fueling strategy.
How Long Before I Start Fueling?
Long runs that require fuel to be brought along are typically at least 75-90 minutes long. There are various recommendations out there, with some saying long run fueling should start with runs that are 60 minutes or longer, while others state 90 minutes or longer. Once our bodies have been continuously working for this long of a period, we start to run low in glycogen (which is stored carbohydrate) and come closer to “hitting the wall” and needing to stop running at the same intensity.
If your training or race itself is going to have several runs that are at least 75-90 minutes long or longer, you should start practicing early on in your training. This way, you can start trying out various products and also train your gut early in the game to take on fuel. Note that time on feet is what matters most here and not pace or mileage or kilometers covered. Your gut has to be trained to take on fuel just like your legs and lungs have to be trained to carry you through a workout whether you run 12 minute miles or 6 minute miles. If you neglect gut training until race day, you may experience gastrointestinal distress, cramping, or hitting the wall.
What Should I Fuel With?
Long run fuel should consist of easily digestible carbohydrates, and very minimal protein, fat, or fiber. You should also take into consideration your hydration strategy for long runs. Things like gels, chews, sports nutrition beverages, or real food can be used to fuel long runs as these contain those quick digesting carbohydrates. Typically mixing various types of carbohydrate like fructose and glucose together are better tolerated in the gut than taking only one type of carbohydrate.
For long runs that are between 75 minutes to 2.5 hours long 30-60g carbohydrate per hour is recommended for female athletes and 60-70g carbohydrate per hour is recommended for male athletes. For long runs over 2.5 hours long, 90g of carbohydrate per hour is recommended for both male and female athletes. It is recommended to take in these carbohydrate amounts in 15-30g doses every 40-50 minutes or so for most traditional sports nutrition fueling products. Typical gels contain about 20-30g carbohydrate per gel, which makes this convenient for fueling, whereas chews contain 45-70g carbs per packet and may need to be taken in two different doses. If you are just starting out from scratch with fueling your long runs, starting with much smaller doses like 10-15g of carbohydrates every 40-50 minutes during your runs may be beneficial to avoid gastrointestinal distress. After a few runs doing this consistently, you can then work your way up to the recommended doses. Check out this podcast episode for more examples of fuel to try out for your next long run.
Application
Applying these recommendations to your training may look slightly different for each runner. Here are some practical tips so you can start practicing now:
Start practicing your fueling early in your training before your long runs are extremely lengthy
If you don’t like the taste of a product to the point where you can’t bring yourself to take it, try out a different flavor or another product consistency
Just because you don’t tolerate a product the first time doesn’t mean it won’t get better. Your gut must be trained just like your muscles in training to be efficient at taking fuel.
Take gels, chews, or food on the run with plain water to avoid gastrointestinal distress
Practice with what you plan to use on race day
Practice carrying your fuel and hydration consistent with what you plan to do on race day
Practice taking in your fuel during faster training runs too so you know how this feels on race day where your pace will also likely be faster than easy pace
Pro tip: for hot summer runs, put your gels or chews in the fridge for an hour or two before you start your run so they don’t get hot immediately during the run
Pro tip: always bring an extra gel or fuel product just in case you need it
References
Vitale K, Getzin A. Nutrition and Supplement Update for the Endurance Athlete: Review and Recommendations. Nutrients. 2019;11(6):1289. Published 2019 Jun 7. doi:10.3390/nu11061289
Wohlgemuth, K.J., Arieta, L.R., Brewer, G.J. et al. Sex differences and considerations for female specific nutritional strategies: a narrative review. J Int Soc Sports Nutr 18, 27 (2021). https://doi.org/10.1186/s12970-021-00422-8