The half marathon is a very long race, so giving your mind a little break by letting other people in the race do some of the pacing work for you helps keep you mentally fresh for the last 3 to 5 miles when you need to bear down and focus.
What About Gels or Fluids?
Hydration: You'll want to try and take a little bit of water or Gatorade during the race. If it's hot, you should aim to take in 6 to 8 ounces of fluid every 5K. If it's cooler, you can take a little less fluid each 5K or space out your stops.
When drinking, you don't have to gulp everything down in 5 seconds; you can take your time and carry the cup with you. You don't need to drink after the 8 to 10 mile marks unless you feel thirsty.
Gels and Other Energy Sources: Using energy gels and other sources of carbohydrates is optional if you plan on finishing under two hours. The body can store close to two hours worth of glycogen in the muscles and liver. Therefore, you theoretically do not need energy gels if you plan on finishing under two hours.
However, some runners may burn through energy slightly faster or draw confidence from having a gel (probably because energy gels stimulate the brain, allowing you to focus more). Find what works for you during your long runs in training and use the same strategy on race day.
More: 10 Race Day Tips
If you do decide to use energy gels, wait until the first 45 minutes to an hour to begin ingesting them. Waiting 45 minutes to an hour gives your body time to get in a rhythm, get comfortable and efficiently process the simple sugars you're ingesting.
If you're running more than two hours, you can take another gel at 90 minutes into the race, if you feel you need it. If you're running under two hours, you do not need two gels because you'd increase the risk of stomach issues due to insulin spikes that would send you crashing the last two miles.
When ingesting a gel/gummy/bar, make sure you always take it with water, not Gatorade or another sports drink, because these energy products contain high amounts of simple sugars. Combining the two at the same time means you're ingesting too much simple sugar at the same time. Your digestive system can't process quickly enough, which may lead to cramps and side stitches.