Unfortunately, every runner is different and because of this, there is not a one-size-fits-all solution to nutrition and hydration during long runs. The key is finding out what works for you in training.
This article presents some basic guidelines to give you a starting point; from there adjust as necessary to find what works best for you. And the time to work out your best nutrition and hydration strategy is during your train-up. Then you can hit race day confident in knowing your plan has been tested and will work.
Less is best:
Research shows us that a 165-pound athlete does best when consuming around 240 to 280 calories per hour while running. That same person most likely is burning anywhere from 400 to 800 calories per hour, which means the ingestion of those calories will not replace all that are consumed, but will help supplement and therefore stall “hitting the wall” for as long as possible. Consuming too many calories, however, can cause one to feel sick.
Make only one small change at a time:
If your nutrition and hydration strategy is not working and you feel changes should be made, only change one thing at a time and then test the change on a couple of long runs. By changing two or more things, you’ll not know what, if any, worked, nor will you know which one could be further tweaked.
Our body naturally stores about 90 minutes of glycogen (at a half marathon pace) or 2 hours at full marathon speed. So unless you have about a two-hour pace on your marathon time, you are going to run out of glycogen in the later part of the race. And while your body can switch over to burning fat, it takes longer to process, thus slowing you down.
To supplement energy, many runners today use carbohydrate energy gel packs to get their nutrition literally “on the run”. The trick is properly timing their consumption.
Again, not everyone is the same. While you may feel the energy boost three minutes after consumption, others may take up to 15 minutes. It all has to do with how fast your body digests it. For some runners, their stomach efficiency slows down when running, because the blood is being diverted to the legs, while in others, it will almost stop.
To figure out when to take an energy gel, do a long run, but only drink water. At which mile did you hit the wall? On your next long run, take a gel two miles before that point and see if that helps. Test your new strategy on a couple more long runs. Adjust if necessary and test again. Eventually you will find the best point to take in some nutrition.
Always take a gel with water. It helps dilute it so that it can be ingested quicker. Don’t take with liquids already having sugar, like sport drinks, as you may get too much sugar.
By testing and perfecting your nutrition and hydration strategy, the only unknown variable that can affect your performance is your nervousness on race day. Over time, and by running a number of races, you can get that under control too.