While running a marathon, you want to make sure that you have plenty of energy to get you to the finish line. You have trained very hard over several months, putting in miles and miles and miles. You do not want a lack of glucose in your system to lead to you hitting the wall or possibly not even finishing the race.
Therefore, it is important to take marathon gels during your big race. Many people have asked me how often they should take marathon gels while running the marathon. The first thing that I would suggest would be to make sure to practice taking marathon gels during your training so that your body is accustomed to the extra sugar entering your system while running. If you implement this strategy during your training runs, your body will be used to it by the time you are ready to run your race. You want to minimize the possible surprises during your big day.
You want to get to the starting line being fully hydrated as well as being carbed up from the week prior. Once you start the race, you will want to start off nice and easily and not get caught up in the rush and excitement at the beginning of the race. Many races will provide energy gels to you at certain mile markers. It is however, advisable to carry some marathon gels along with you during your race.
Once you get settled in to the race and have found your place in the crowd, just relax and go with the flow for awhile. You should have plenty of energy for the first several miles because of the carbo loading you did during the week as well as the hydrating you did the day and night before your race. It is advisable to hold off on the energy gels until you are about 45 minutes into the race. At this point, you can take your marathon gel. It is probably a good idea to do this once you get to a water stop along the course. You will want to take your marathon gel with a cup of water rather than a sports drink like gatorade. Both the marathon gels and the sports drinks are loaded with sugar. Taking both of them at the same time could be too sweet for your stomach and could potentially lead to an upset stomach.
It is suggested to continue this pattern of ingesting your marathon gels. That is, to take one approximately every 45 minutes or so. Depending on where the aid stations are positioned on the course, you may want to take a marathon gel at the station that is closest to the 45 minute mark, give or take a few minutes. So, if you are planning on running a 6 hour marathon, you will end up taking 8 marathon gels. On the other hand, if you are running a 2 and a half hours, you will probably only consume about 3 gels.