Energy foods post-op during heavy exercise

Hello all, my first time posting to this board. I'm a posto-op RNY and have become very physically active after losing 138 pounds. Specifically I've taken up rock climbing. My question regards the use of carbohydrate heavy energy foods during this activity. My surgeon, like most, recommends a low-carb diet, and of course there is the issue of sugars and dumping. What I'm interested in using are some of the carb gels while I'm out actually climbing. I've found a couple that have almost no sugar. They have no protein to them but I can get that elsewhere. Does anyone have experience with this type of product, or any other type of energy product during a heavy drain activity? I realize that most "energy foods" have a high amount of sugar, hence my interest in the gels. Any input is greatly appreciated. Thanks, Charles Shepherd