Smart Carb Cycling – When Cyclists Should (and Shouldn’t) Eat Carbs

Cyclists have long been advised to consume high amounts of carbohydrates, particularly through practices such as carb-loading before races or intense training sessions. However, recent advances in sports science suggest that the optimal approach to carbohydrate intake is more nuanced, focusing on timing and quantity relative to the specific demands of each workout. Rather than simply increasing or decreasing carbs indiscriminately, cyclists can benefit from a strategic “smart carb” cycling method that aligns carbohydrate consumption with training intensity and goals. Research indicates that deliberately training with low muscle glycogen stores during certain low-intensity sessions can enhance training adaptations. This approach, sometimes referred to as “sleep low, train low,” involves restricting carbohydrate intake before less demanding workouts to stimulate the body’s fat oxidation capacity and improve endurance. Such adaptations help cyclists generate more power, sustain efforts on long climbs, and respond effectively during competitive situations by optimising the use of muscle glycogen for when it is most needed. The key to implementing smart carb cycling lies in periodising carbohydrate intake according to the upcoming training load. For example, after a high-intensity, long-duration ride, a cyclist might reduce carbohydrate intake before a subsequent low-intensity session, perhaps by consuming a low-carb dinner and a protein-rich breakfast. Conversely, in preparation for a demanding workout, carbohydrate consumption should be increased to ensure sufficient glycogen availability. This strategy is supported by the “fuel for the work required” model developed by Samuel Impey and colleagues, which categorises meals by carbohydrate content based on the next day’s training demands. Ultimately, carbohydrates serve not only as fuel but also as modulators of training adaptations. By manipulating carbohydrate availability thoughtfully throughout the training cycle, cyclists can enhance their physiological responses and improve performance outcomes. To maximise these benefits, it is advisable to work with a registered dietitian experienced in cycling nutrition who can tailor dietary plans to individual training schedules and goals, ensuring that carbohydrate intake supports both performance and recovery effectively.