Why Pre-Workout Carb Timing Matters
Carbohydrates are stored as glycogen in your muscles and liver, making them the fastest-available fuel source during exercise. The same amount of carbs can affect you very differently depending on when you eat it. If your workout is 3-4 hours away, you have plenty of time to digest around 2g of complex carbs per kg of body weight to fully top off glycogen stores. If training starts within 30 minutes, stick to a small amount of fast-digesting simple carbs so you get quick energy without GI discomfort.
Why Higher Intensity Needs More Carbs
High-intensity intervals or competition burn through glycogen much faster than low-intensity training, so they call for more carbohydrate intake. This calculator applies an intensity multiplier so the same body weight yields a different target depending on how hard you're training. For sessions longer than 60 minutes, stored glycogen alone often isn't enough — taking in 30-60g of carbs per hour during the workout helps sustain performance in the later stages.
Adjust for Your Own Body
This calculator simplifies general sports nutrition guidelines into a quick reference. Actual digestion, tolerance, and sport-specific demands vary by person, so use this as a starting point and fine-tune based on how you feel.
Frequently Asked Questions
Choose easy-to-digest complex carbs like rice, oats, or sweet potato at around 2g per kg of body weight to fully top off muscle and liver glycogen stores.
Yes, but stick to a small amount of fast-digesting simple carbs like a banana, honey, or a sports drink. High-fiber or high-fat foods this close to training can cause GI discomfort.
Yes, for moderate-to-high intensity sessions over 60 minutes, taking in an extra 30-60g of carbs per hour helps reduce the performance drop-off later in the session.