Yams vs. Squash… for Pre Workout Fueling?

Recently, one of my clients asked whether she could substitute butternut squash for yams in order to prepare for her endurance training.


Great question, and one I've  been asked before.

If you're deciding which to opt for pre-long-endurance workout, you'll want to go for the one with the higher Glycemic Index (The Glycemic Index (GI) is a numerical scale used to indicate how fast and how high a particular food can raise our blood glucose (blood sugar) level. A food with a low GI will typically prompt a moderate rise in blood glucose, while a food with a high GI may cause our blood glucose level to increase above the optimal level.) & Glycemic Load (which is is a ranking system for carbohydrate content in food portions based on their glycemic index (GI) and the portion size. Glycemic load or GL combines both the quality and quantity of carbohydrate in one ‘number’. It’s the best way to predict blood glucose values of different types and amounts of food. The formula is: GL = (GI x the amount of available carbohydrate) divided by 100.)

Here's the skinny:

Yes, both yams and butternut squash ARE paleo.  Baked yam has a glycemic index of 54, and a glycemic load of 19.  Butternut squash, in comparison, has a listing of 75 and 5, respectively.  

There you have it- pre workout, yam wins out, while butternut squash mixed with some other lower glycemi load veg & proteins with a nice topping of healthy fats via avocado or olive oil, perhaps, would be a great non-workout meal.