It is important for athletes to recognize that the gels do not replace the need to consume fluid and electrolytes. Some athletes opt for the gels over liquids and food because gels provide a concentrated dose of carbohydrate in a very dense form that is easy to digest and light to carry. Others hate gels because of their dislike of the texture, sweetness, and intensity of the flavor. As for the science, a preliminary report on gels shows similar glycemic response when compared to liquid or solid foods with the same amount of carbohydrates, although the liquid and gel carbohydrates induced a slightly faster rise in glucose in the first 15 minutes of exercise with a corresponding increase in insulin that was higher with the liquid carbohydrate. While it appears that gels may be effective in providing energy for exercise, the biggest challenge may be taking in enough fluid along with them.
Most athletes already compete in a state of dehydration.
If they do not drink enough fluid when consuming a gel they may slow down the absorption of both the carbohydrate and water resulting in poor performance. During exercise, especially in hot and humid climates, the greatest need is to replace fluids lost during sweating. If an athlete wants to use carbohydrate gels during exercise, it should be matched with an adequate amount of water. For example, for a 1.4 oz. I also recommend that the athlete examine the gel's electrolyte content, which may promote fluid retention.