The Carb Spectrum
A sugar-free electrolyte tablet is roughly 0-1 g of carbs in a 500 ml bottle. A standard supermarket sports drink (Gatorade, Powerade) is around 30 g per 600 ml - roughly 6% by mass. Endurance-specialty products like SiS Beta Fuel sit at 8% or higher and are designed for sustained energy at race intensity.
What the Numbers Are For
At low-to-moderate exercise intensity for less than an hour, your body has plenty of stored glycogen - you don't need carbs in the bottle.
For 60-120 minutes of moderate-to-hard exercise, the ACSM has long recommended around 30-60 g of carbohydrate per hour from a sports drink or gel.
For very long sessions (3+ hours), trained athletes can use more - up to 90 g/hour using carbohydrate blends. This is what high-carb endurance products are formulated for.
Carb Type Matters Too
Most sports drinks use a mix of glucose, sucrose, and (increasingly) fructose. The reason for the mix is that glucose and fructose are absorbed by different transporters in the gut - combining them lets you take in more total carbohydrate per hour without overwhelming a single transport pathway. Endurance products like Beta Fuel lean into this with explicit glucose:fructose ratios.
If You're Doing a 45-Minute Spin Class
You don't need a high-carb drink. Water, or a hypotonic electrolyte product (Nuun, Dr.Hydrate, sugar-free Powerade Zero) covers it.
If You're Doing a 4-Hour Ride
Now the math changes. A standard sports drink delivers ~30 g per 600 ml - across 4 hours, that's 120 g if you finish a bottle an hour. Many cyclists pair sports drink with gels or solid food to push the carbs-per-hour rate higher. Sports Drinks for Cyclists goes deeper.
Frequently Asked
How much carbohydrate should I take during exercise?
ACSM guidance suggests 30-60 g/hour for moderate-to-hard sessions of 60-120 minutes. Trained endurance athletes can use up to 90 g/hour with glucose-fructose blends on very long events. For sessions under an hour, you don't need in-session carbs.
Is high-carb fuelling safe?
For trained athletes who've gradually adapted their gut, 80-90 g/hour is supported by current research. Going to that level cold turkey on race day tends to cause GI distress. Train your gut for the dosing strategy you'll race with.
Why do some products use both glucose and fructose?
Glucose and fructose are absorbed by different intestinal transport proteins (SGLT-1 vs GLUT-5). Combining them lets the gut handle more total carbohydrate per hour than glucose alone.
Are maltodextrin and glucose the same?
Maltodextrin is a chain of glucose molecules. Once digested it becomes glucose, but during drinking it's less sweet than table sugar, which lets brands deliver more carbohydrate per ml without overpowering sweetness.
