• Matt Schoenherr

The perfect pre-workout smoothie for athletes with diabetes

Updated: Jan 14, 2019

Waking up for early morning workout can be hard enough.

Properly fueling for that workout is even harder.

Waking up early, properly fueling, and successfully managing your blood sugar during that workout can seem nearly impossible. This article will give you the info needed to successfully complete a morning workout with the proper nutrients and glucose control.

First, lets clear the air on one of the newest fads in the fitness industry: fasted exercise. There is a lot of hype around fasted exercise for endurance athletes and power athletes alike. This is because of new research that suggests training fasted makes the body more efficiently at burning fat as energy. While the body may become more efficient at burning fat as fuel during exercise, other research shows that although it trains the body to use a different fuel source more effectively, it does not translate to better performance by distance athletes.

More importantly, fasted exercise can be dangerous for an athlete who is insulin dependent. 70% of liver glycogen can be depleted after 8 hours of fasting. In other words, 70% of what keeps you safe during low blood sugars is gone. A large chunk of the remaining 30% will be used in the first 30 minutes of exercise. Liver glycogen is the body's back up plan during low blood sugars. Fasted exercise depletes liver glycogen and leaves an insulin dependent athlete vulnerable to dangerous lows that can result in hypoglycemic seizure during exercise, and up to 24 hours later.

If you are willing to take that risk in the name of weight loss, try a different approach. Fasted exercise is more likely to result in over-eating later, potentially contributing to weight gain instead of weight loss. In short, a large majority of workouts should be completed when adequately fueled.

The goal of morning fuel is to have an adequate amount of glucose available to optimally perform the workout, creating a fitter, stronger athlete. With an athlete with diabetes, this needs to be done in a way that keeps blood glucose between 80 and 180mg/dL. Gulping down a Gatorade as you wake up will probably result in a significant spike in blood sugar at the beginning of a work out and low 20 minutes later. What is needed is the right balance of carbs, protein, fat, and insulin to optimally time the digestion and fuel delivery to keep blood sugars stable.

The Fuel

To keep the digestion of carbs steady, minimizing the chance of a spike blood sugar, the breakdown of macronutrients should be 50-65% of calories should be from carbohydrates, 15-25% protein, and 15-25% fat.

Here is a perfect, easily digestible smoothie recipe from TrainingPeaks.com:

  • 1 banana

  • ⅛c up quick oats

  • ¼ cup blueberries

  • ⅓ scoop protein powder

  • 1 tbsp peanut butter

  • ice

  • water

38g carbs, 15g protein, 9.5g fat

The Insulin

Especially if this consumed before a morning workout, a small insulin bolus is probably needed. This macronutrient breakdown is pretty good at counteracting basal insulin, but a decrease in basal insulin may still be needed.

The size of bolus depends on the duration and intensity of the workout, the athlete’s training status, and other smaller variables. A good starting point for a moderate intensity or steady state workout is 50% of a normal carb bolus.

The Timing

This example smoothie and the insulin to go with it should be consumed 15-20 minutes before your workout begins. Any early may result in a high blood sugar.

With diabetes, always ensure that you have 15 grams of carbs available for every 20 minutes of exercise you plan to perform. If the workout is longer than 60-90 minutes, an electrolyte drink with carbs should be consumed during exercise.

To get the greatest return on your investment, make sure to have a recovery meal within 30 minutes of exercise. This is also the most effective way to replenish muscle glycogen

To get dialed into your specific needs, make an appointment with me at info@activediabetes.com.


  1. Hearris, M.A., Hommond, K.M., Fell, J.M., Morton, P.M. Regulation of muscle glycogen metabolism during exercise: implications for endurance performance and training adaptations. Nutrients. 10(3): 298. 2018.

  2. Kattouf, R. "How to properly fuel your morning workout."Training Peaks. 2016. https://www.trainingpeaks.com/blog/how-to-properly-fuel-your-morning-workout/