Bonking / Cycling Nutrition / Endurance Fueling
A plain-English explanation of bonking, why it happens, and why prevention beats rescue. This guide is written for cyclists first, with notes that also apply to runners and triathletes when the same endurance-fueling principles carry over.
Good fueling is not about chasing a perfect number for its own sake. The goal is to deliver enough carbohydrate, fluid, and sodium for the session you are actually doing, using products and foods you can tolerate when the effort gets real.
Prevention beats rescue
- Bonking usually means running low on available carbohydrate for the work you are asking your body to do.
- Warning signs can include sudden fatigue, mental fog, low motivation, and poor power output.
- The better strategy is to fuel early and consistently instead of waiting for the rescue moment.
Set the carb target first
For many endurance rides, a useful starting range is roughly 30-60 grams of carbohydrate per hour for moderate sessions and 60-90 grams per hour for longer or harder events. Intakes above 90 grams per hour can work for some trained athletes, but they should be practiced gradually with multiple carbohydrate sources and products that sit well in your stomach.
The target should reflect ride duration, intensity, heat, your gut tolerance, and what you can realistically carry. A two-hour endurance ride and a five-hour event with climbs should not automatically use the same plan.
Use this in a BonkGuard race plan
Start on Race Day with the event date, distance, and expected finish time. Review editable carbohydrate and fluid targets, reveal optional sodium guidance when it is useful, then choose the foods, gels, chews, drink mixes, and bottles you expect to carry.
Use Overview to compare targets with Planned intake from the generated schedule and prepared bottles. Check Schedule for timing, Packing for quantities and bottle preparation, and Practice this plan for a shorter rehearsal before you decide the plan is Race Ready.
Useful next reads
- Beginner’s Guide to Cycling Nutrition
- Advanced Guide to Cycling Fueling
- How to Avoid Bonking on Long Bike Rides
- Why Cyclists Underfuel During Training Rides
- How Often Should You Eat on the Bike?
- How to build a complete race-day fueling plan
Key takeaway
Bonking usually means running low on available carbohydrate for the work you are asking your body to do. Build the plan around the full session, then keep the execution simple enough to follow when the ride gets hard.
Educational note
This article is educational and is not medical or nutrition-treatment advice. Athletes vary widely in tolerance, sweat rate, health history, and goals. Practice fueling and hydration changes in training, not for the first time on race day, and work with a qualified professional when you need individualized medical or nutrition guidance.