The reputation of sugar has taken a hit in mainstream health advice, but for runners, the story is far more complex. While a diet high in processed sugars is unhealthy for a sedentary person, an athlete’s physiological needs are different. Carbohydrates, including simple sugars, are a runner's primary fuel source, and knowing when and what kind to consume is key to unlocking peak performance. This guide breaks down the science behind fueling with sweets, detailing the pros, cons, and best practices.
The Role of Carbohydrates: Simple vs. Complex
Carbohydrates are the body's preferred source of energy for athletic activity. They are primarily stored as glycogen in the liver and muscles. For runners, the timing and type of carbohydrate intake are critical for maintaining energy levels and preventing fatigue.
- Simple Carbohydrates (Sugars): These are quickly digested and absorbed, providing a rapid energy boost. They include glucose, fructose, and sucrose. Sources range from natural fruits and honey to processed sweets like gels and gummies. Their fast-acting nature makes them ideal for in-run fueling during endurance efforts.
- Complex Carbohydrates: Found in whole grains, starchy vegetables, and legumes, these carbs take longer to break down. They provide a steady, sustained release of energy and are the ideal foundation of a runner’s everyday diet.
Strategic Timing is Everything
For runners, the question isn't whether to eat sugar, but when. The context of your training dictates whether simple sugars are beneficial or detrimental.
Sweets as Mid-Run Fuel
For runs exceeding 60-90 minutes, a runner's glycogen stores begin to deplete. At this point, simple sugars become a critical fuel source to maintain performance and prevent 'hitting the wall'. The goal is to consume quickly digestible carbs that won't cause gastrointestinal distress. Many runners find that commercial sports nutrition products, formulated with a specific mix of sugars (like glucose and fructose), are highly effective. However, many also successfully use regular jelly-based sweets or gummies.
The Post-Run Recovery Window
Immediately following an intense or long run, muscles are highly receptive to replenishing glycogen stores. Consuming high-glycemic carbohydrates within a 30-45 minute window post-exercise helps speed this process, which is vital for recovery and adaptation. Combining simple carbs with protein further enhances this effect. This is a prime time for a sweet treat, like a glass of chocolate milk, a handful of sweets, or a simple carbohydrate and protein snack.
The Risks and Downsides of Sweets for Runners
While strategically timed sweets can be beneficial, there are definite risks to overconsumption or poor timing.
- Sugar Crashes: Consuming a large amount of simple sugar outside of exercise can cause a rapid spike in blood sugar, followed by an insulin surge and a steep crash in energy. This leaves you feeling sluggish and fatigued, negatively impacting training.
- Gastrointestinal Distress: During a run, blood is diverted away from the digestive system to working muscles. Consuming too much sugar, especially high-fat or high-fiber sweets, can overwhelm the gut, causing cramping, nausea, or diarrhea. Athletes must train their gut to tolerate fuel and experiment with different options.
- Empty Calories: Consuming excessive refined sugars means you are filling up on calories with little to no nutritional value, displacing more nutrient-dense whole foods. For the majority of a runner's diet, prioritizing complex carbs from sources like fruits, vegetables, and grains is essential for overall health and sustained energy.
Best and Worst Sweets for Runners
Not all sweets are created equal, especially when it comes to fueling your run. The best options are those with simple carbs, low fiber, and low fat content to ensure quick digestion.
Best Options:
- Jelly sweets (e.g., gummy bears, jelly beans): Packed with sugar and easily digestible.
- Dates: A natural, portable source of quick sugars and potassium.
- Dried Mango: Another natural, easily carried option full of carbohydrates.
- Honey: Can be consumed directly or via honey sticks for a fast-acting carb hit.
- Fruit Purees/Pouches: Gentle on the stomach and easy to consume while moving.
Worst Options:
- Chocolate (especially milk chocolate): The high fat content slows digestion and can cause stomach upset during a run.
- High-Fiber Sweets: While fiber is generally good, consuming it mid-run can lead to digestive issues.
- Baked Goods (e.g., cakes, pastries): These contain a mix of sugar, fat, and fiber, making them too heavy for mid-run fueling.
Comparing Commercial Fuel vs. Candy
For mid-run fueling, runners often choose between purpose-built sports nutrition products and standard candy. Here is a comparison:
| Feature | Commercial Sports Gels / Chews | Regular Candy (e.g., Gummies) |
|---|---|---|
| Carb Composition | Often an optimized mix of glucose and fructose for maximum absorption (90g/hr). | Typically sucrose or corn syrup, less optimized for high-volume intake. |
| Electrolyte Content | Often contains added electrolytes like sodium and potassium. | Typically has little to no electrolytes, requiring separate intake. |
| Digestibility | Designed for easy, low-stress digestion during intense exercise. | Can be stickier, chewier, and potentially harder on the gut, especially with dehydration. |
| Convenience | Comes in portable, easy-to-open packages. Gels can be consumed quickly. | Can be less convenient to carry and harder to consume while breathing heavily. |
| Cost | Can be significantly more expensive per gram of carbohydrate. | More budget-friendly and widely available. |
A Balanced Approach: Combining Sweets with Whole Foods
Most sports dietitians recommend an 80/20 rule: 80% of your diet should consist of nutrient-dense whole foods, with 20% flexibility for less-healthy options. This principle allows for the strategic use of sweets without compromising overall health. For long-term health and performance, whole food carbohydrate sources should be prioritized. However, for immediate fueling needs during and immediately after demanding training, simple sugars offer a powerful and efficient solution.
Furthermore, 'gut training'—exposing your digestive system to the types and quantities of fuel you'll use during a race—is a strategy that can help minimize gastrointestinal issues. This involves experimenting with different fuel sources, including sweets, during your long training runs.
Conclusion: Sweets as a Tool, Not a Staple
In summary, the answer to the question, are sweets good for runners? is a qualified 'yes.' They are an excellent tool for specific performance and recovery scenarios due to their rapid energy delivery. For sustained energy and overall health, a runner's diet should be built on a foundation of complex carbohydrates, lean protein, and healthy fats from whole foods. Using sweets wisely, as a strategic performance tool rather than a daily habit, allows runners to maximize their training and race potential without derailing their health goals. The key lies in understanding the 'why' and 'when' of sugar consumption and always listening to your body's response during training.
For more detailed sports nutrition advice, consult the guidelines from Sports Dietitians Australia: The Glycaemic Index and Sports Performance.
