Q: I exercise first thing in the morning on an empty stomach. Besides hydrating, what do you suggest I consume post-workout? Would a smoothie or banana suffice?
A: After quenching your thirst with pure water, best to leave anything that tastes sweet aside unless you want to undo the benefits of the exercise you just completed.
Exercising on an empty stomach affords you the benefit of low baseline insulin levels, mostly from the overnight fast and further bolstered by your morning workout. Exercise makes cells more sensitive to insulin, thereby removing it from circulation. This allows glucagon, the fat burning hormone, to come out and get to work. This can only occur when insulin is low.
By choosing a fruit smoothie or banana—a medium banana is a whopping 27 grams of carbs—or another carb rich option like flavored yogurt, cereal, or a flavored protein shake as your post-exercise meal, you’re causing a rise in blood sugar that subsequently will produce a rise in insulin, thereby putting you in fat storage mode. Why would you do that? Moreover, beneficial human growth hormone beckoned by exercise is blunted by the insulin spike caused by your high carb meal. Bummer!
Most people choose carb-rich foods in an effort to restore glycogen levels post workout. But did you know that glycogen restoration is phase one of fat storage? I ask you then, what is the point of your exercise other than to burn carbohydrate and then store it back again? Unless you’re an elite athlete who relies on glycogen stores for competition, this doesn’t help you achieve your goal of burning fat. Indeed, fat burning is shut down due to the carbs you just ate or drank.
Your best options are eating an adequate amount of savory proteins and fats like an omelet or a steak after a workout. That keeps insulin low and allows glucagon to continue burning fat while the protein in your meal helps to repair and restore muscles post exercise.
To your health!
Leyla Muedin, MS, RD, CDN
