This question is about Nutrition and Cycling
If you’re cycling for 90 minutes or more, consume a small amount of energy gel every 15-30 minutes. After 60-90 minutes your body has used up most of its stored carbohydrate (glycogen) and research suggests that you need to replace that carbohydrate to maintain energy and maximize performance [1]
A good rule of thumb is to aim for roughly 30-90g/ hour if you’re cycling for more than 90 minutes [1]
[1] Kerksick, C.M., Wilborn, C.D., Roberts, M.D. et al. ISSN exercise & sports nutrition review update: research & recommendations. J Int Soc Sports Nutr 15, 38 (2018). https://doi.org/10.1186/s12970-018-0242-y