When should I use energy gels during running?

Energy gels deliver 20-30g of rapidly absorbed carbs in a small package, making them the standard fueling choice for endurance runners in races over 75 minutes. The rule of thumb: your body can use stored glycogen for about 90 minutes of running before performance drops. After that, you need exogenous carbs. Start fueling before you feel you need it — take your first gel at minute 30-45, then another every 30-40 minutes. Total target: 30-60g of carbs per hour. Faster runners and those in heavy training can handle 60-90g per hour with gut training. Always take gels with 150-250 ml of water — gels are concentrated sugar, and without water they sit in your stomach undigested and cause cramps, nausea, or diarrhea. This is the #1 gel mistake. Different gel types: glucose-fructose blends (Maurten, SIS Beta Fuel) are absorbed faster and tolerated better than pure glucose; caffeinated gels (100 mg) give a performance boost in the final third of long races. Brand matters less than tolerance — find 1-2 you can stomach and stick with them. Practice gel timing and brands during training runs of 90+ minutes, starting 6-8 weeks before a race. Never experiment with new gels on race day. If you hate gels, alternatives include dates, gummies, sports drinks, rice cakes, or pocket-sized bananas.