How much drink mix to put in each bottle for your carb target per hour, the concentration in percent, and the glucose to fructose ratio for long races.
Fills in the carb target. Change it if you like.
For example 1, or 0.5 for one every two hours
Read it off the tub
Optional. Gives grams of powder.
Per bottle
3.2 scoops
Stronger than the 6 to 8 % that is typical for a drink. Use more bottles per hour, or cover part of the target with gels and plain water alongside.
Carbs per bottle is your hourly target divided by the bottles you drink per hour. Divide that by the carbs in one scoop and you get scoops per bottle, and with the weight of a scoop, grams of powder. Concentration is carbs per bottle over the bottle volume, shown as grams per 100 ml, which is the same number as percent. The target is prefilled from the race fueling calculator for the race length you choose, using our estimate of a typical finish time, and you can change it.
About 6 to 8 percent is the typical range for a sports drink. Much stronger and it can sit in the stomach, so a high target is better split across more bottles, or covered with gels taken with plain water. The calculator warns above 8 percent. That line is a rule of thumb and our estimate, not a hard limit, and tolerance differs from athlete to athlete.
The gut absorbs glucose through one route, which limits it to roughly 60 g per hour on its own. Adding fructose uses a second route. Jeukendrup (2014) recommends multiple transportable carbohydrates above about 60 g per hour, up to about 90 g per hour for the longest events, and the studies he reviews mostly used glucose to fructose 2:1. Rowlands et al. (2015) reviewed fructose and glucose together and concluded that a ratio of about 0.5 to 1.0 parts fructose to 1 part glucose, at 1.3 to 2.4 g per minute, likely benefits endurance performance lasting 2.5 to 3 hours, and that a 0.8 to 1 fructose to glucose ratio (about 1:0.8 glucose to fructose) gave the highest exogenous carbohydrate energy at 1.5 to 1.8 g per minute.
Many race mixes already use a blend like this, so check the label. Train with the exact mix first, then count your gels with the gel calculator. More in triathlon nutrition basics, and see the caffeine calculator if your mix has caffeine in it.
About 6 to 8 percent, which is 6 to 8 g of carbs per 100 ml, is typical for sports drinks. Stronger mixes need plain water or more bottles alongside them.
It depends on your target and how many bottles you drink. At 60 g of carbs per hour from one 750 ml bottle a drink holds 60 g of carbs, which is 8 percent. Enter the carbs per scoop from your tub and the calculator gives you the scoops.
It is a blend of two parts glucose to one part fructose that uses two absorption routes in the gut, so you can take in more than about 60 g of carbs per hour. Jeukendrup (2014) recommends multiple transportable carbohydrates for intakes up to around 90 g per hour.
Not at 60 g of carbs per hour or less. Above that, a glucose and fructose blend is what the literature recommends, and many sports drinks already contain one.
You can, but it is stronger than the typical 6 to 8 percent and some athletes find it upsets the stomach. Test it in training, or use more bottles per hour and add gels with water.
