For anyone who trains seriously, one question comes up again and again: how many carbs do you actually need during exercise? The fitness world has drifted toward “more is better,” with some endurance athletes now aiming for very high carbohydrate intakes during long sessions. But recent research delivers a useful reality check — when it comes to carbs during exercise, moderate intake can match or even outperform very high intake for many people, while being gentler on the gut. Understanding how much you truly need can save you money, spare you stomach trouble, and help you perform better.
Why Carbs During Exercise Matter
Carbohydrate is the body’s most readily available fuel for moderate-to-high-intensity exercise. Your muscles and liver store carbohydrate as glycogen, but those stores are limited — during prolonged endurance efforts, they gradually deplete, and as they run low, pace and power fade and perceived effort climbs. Consuming carbohydrate during exercise helps by providing an external fuel source that spares glycogen and keeps blood glucose stable, which is why a gel, drink, or piece of fruit partway through a long ride or run can noticeably lift performance in the later stages. The benefit is well established for sustained efforts lasting longer than about an hour; for shorter sessions, the body’s own glycogen stores are usually more than sufficient and extra fuel adds little of value.
How Much Do You Actually Need?
This is where the picture has become clearer and more practical. Sports-nutrition guidance has long suggested that as exercise duration increases, so should carbohydrate intake — up to fairly high hourly amounts for elite, multi-hour events. But the important nuance from recent research is that higher isn’t automatically better, and the right amount depends heavily on who you are and what you’re doing.
For recreationally trained individuals, an intake of around 40 grams per hour can be enough to meaningfully enhance endurance performance. Pushing well beyond that — toward the 90 grams per hour figures sometimes quoted for elite competitors — is often unnecessary for everyday athletes and carries a real downside: a higher risk of gastrointestinal discomfort, the bloating, cramping, and nausea that can derail a session more effectively than running low on fuel ever would. In other words, for most people the extra carbohydrate beyond a moderate amount doesn’t buy meaningful performance, but it does raise the odds of stomach trouble. The very high intakes have their place for elite, long-duration endurance athletes, but they are a specialized strategy, not a default that recreational athletes should copy.
Intensity and Duration Change the Equation
How hard and how long you go both shape your fuelling needs. At higher intensities, the body relies more heavily on carbohydrate as fuel and glycogen availability becomes more important, so having adequate carbohydrate on board matters for hard efforts. For longer, steadier sessions, the goal is to top up fuel gradually to protect glycogen stores over time. Research has also found that the exact pattern of carbohydrate intake during exercise — front-loading it, back-loading it, or spreading it evenly — makes little difference to performance, which is reassuring: you don’t need a complicated schedule, just a sensible steady intake that suits your stomach. The practical implication is that consistency and tolerability matter more than precise timing.
Train Your Gut
One of the most useful ideas in modern sports nutrition is that the gut is trainable. The ability to absorb and tolerate carbohydrate during exercise improves with practice, so athletes who want to fuel at higher rates need to build up to them gradually in training rather than attempting a large intake for the first time on race day. This is why “nothing new on race day” is such durable advice: your fuelling strategy, like your training, should be rehearsed. Starting with modest amounts and slowly increasing — while paying attention to how your stomach responds — lets you find the intake that gives you energy without discomfort. For most recreational athletes, that sweet spot is more modest than the headlines suggest.
Practical Fuelling Guidelines
- Under an hour: For most sessions shorter than about 60 minutes, water is usually enough; your glycogen stores cover the effort.
- One to two-plus hours: Aim to take in carbohydrate during the session — roughly 30–60 grams per hour suits most recreational and serious amateur athletes. Around 40 grams per hour is a sensible target for many.
- Long, elite-level events: Higher intakes (toward 90 grams per hour) can help, but only if your gut is trained for them; build up gradually.
- Choose what sits well: Sports drinks, gels, bananas, dates, and other easily digested carbohydrate sources all work — pick what your stomach tolerates.
- Practice in training: Rehearse your fuelling in normal sessions so race day holds no surprises.
The takeaway is refreshingly practical: when it comes to carbs during exercise, more is not always better. Match your intake to your intensity, duration, and personal tolerance rather than chasing the highest numbers you read about. For the majority of people who train, a moderate, well-practised fuelling strategy delivers the performance benefit without the stomach problems — and that is a smarter, more sustainable way to fuel your training.
Sources
- PubMed — Carbohydrate intake during steady-state exercise and subsequent time-trial performance (2026)
- International Journal of Sport Nutrition and Exercise Metabolism — Carbohydrate Distribution During Intense Cycling (2025)
The information in this article is for educational purposes only and does not substitute professional or medical nutrition advice. Individual fuelling needs vary; consult a qualified professional for personalized guidance.
