If you are exercising vigorously for 1-2 ½ hours then it’s smart to consume a 120-240 calories (30-60 grams of carbs, lower amount for person weighing less and/or less vigorous exercise) per hour snack or beverage to keep your blood sugar and energy levels stable throughout your hike.
If you are exercising vigorously for over 2 to 3 hours then it’s smart to consume a 240-350 calories (60-90 grams of carbs) per hour snack or beverage to keep your blood sugar and energy levels stable throughout your activity.
We’ve known for a long time that carbohydrate is the critical fuel for performance that carbohydrate ingestion during exercise can increase exercise capacity. For those activities lasting greater than 2.5 hours, consume 90 grams per hour of only a multiple transportable carbohydrate.
A multiple transportable carbohydrate is absorbed by different methods (transporters or pathways) in the intestine and this means a better delivery of the carbohydrate, increased fluid delivery, less gastrointestinal distress, reduced fatigue and higher performance. The carbohydrate source should be a mix of glucose and fructose, or maltodextrin and fructose in a ratio of roughly 2:1, so there is 60 g/h of glucose or maltodextrin (to saturate the SGLT1 transporters) and 30 g/h of additional fructose for oxidation. Source: http://www.gssiweb.org/Article/sse-108-multiple-transportable-carbohydrates-and-their-benefits
Avoid low-calorie version. Low calorie means less sugar and the purpose of a sports drink is to replenish glycogen.
Look for a combo of glucose and fructose, called multiple transportable carbohydrates since those carbs will be absorbed faster, will enhance endurance by increasing exogenous carbohydrate oxidation, reduce the reliance on endogenous carbohydrate stores and cause less GI distress.
The most efficient and effective sports drinks have a carbohydrate concentration of 6 to 8 percent. This concentrations allows the fluid to absorb into the bloodstream quickly, at about the speed of water.
Avoid pure fruit juice since this will provide too much fructose and can cause digestive issues when you are doing heavy exercise.
Electrolytes such as potassium and sodium are necessary, extras like vitamins or herbal supplements aren’t necessary.
Energy Gels and Solids
Energy gels and solids such as gummies, are much more calorically-dense than sports drinks, and are designed to enable a person to get a high amount of carbs intake during a difficult long distance event.
When you eat energy gels, drink water so it digests and enters the blood stream. And don’t take with as sports drink or you can get too much sugar at once time.
Gels can be hard on the digestive system causing cramps, bloating and diarrhea and nausea. So practice using these.
The least expensive carbohydrate replacement is plain honey. Plus it has right ratio of glucose and fructose for maximum carb absorption, and there aren’t any additives.
Choose real food instead. Many of these types of bars have lots of unhealthy saturated fat and other processed junk like partially hydrogenated soybean, palm, and palm kernel oils, additives, simple sugars.