GI stands for Glycemic Index and refers to how certain carbohydrates affect your blood sugar levels. Now if you’re someone who need’s to prevent blood sugar spikes like with type 2 diabetes for instance then its obviously something you care about. That’s great and all but I don’t want to talk about those implications.
I care about how I can use the information I know on GI’s to improve my fitness routine/habits. GI’s are categorised on a scale of 1 to 100, where higher means it will increase the blood sugar level much faster. Pretzels, bagels, popcorn, that sort of stuff. Low GI foods will increase the blood sugar levels but they’ll do it more gradually.
We need these sugars for energy, respiration. And our main energy-system, the aerobic system, uses this to efficiently provide ATP (a special chemical which gives us energy).
Take this with a pinch of salt because this is more my own analysis. Depending on the activity you’re going to need a certain blood sugar level to supply enough energy. If the activity is not so demanding it makes sense to fuel that with low GI foods. On the other hand, for more strenuous activity, the closer you are to the activity the higher the GI should be to supply more energy. There’s a common saying to ‘carb up’ before going to the gym.
So that’s all I’m saying. Be picky with the carbs you eat, eat low GI for low activity and high GI for high activity. Why not eat high GI all the time? Having high blood sugars is not good for you! Plus its inefficient, by eating low when you’re low you have more juice in the tank for your exercise.
TL;DR Eat low GI food for low activity, and high GI food for high activity. Always use the appropriate fuel