Dietitian Confessions, Nutrition, Q & A

Should I eat before a workout?

There was a disturbing time  for me when running was more about burning calories than it was about feeling energized and free. It wasn’t entirely my fault.  My Mom and Dad’s eating and activity behaviors showed me that calories were something to restrict and burn and, to limit them at all costs. So when a dietitian told me that  calories could help improve my running performance I was confused. I actually was so distrusting if this skinny woman with glasses that I had to become a  dietitian to study this for myself.

Yes, it is true you don’t want to eat more calories than you burn unless you want to put on weight (SOME people DO benefit from putting on weight).  More importantly for an active person already at a healthy weight is eating enough calories to energize the body’s potential to run far and sometimes fast(er).  Timing those calories has proven beneficial to me as well. That brings me to the topic at hand. I recently did an interview where they asked me this question:

Should you eat before a workout?

The simple answer is yes. The complicated answer addresses when, how much, what, and why you should eat before a workout. Here are some general rules of thumb that I employ. Also, I have come to believe that calories are my friend, not my enemy and after several years of struggling we have learned how to play well together.


Real Premium Calories  Eaten by Scott Jurek on his Appalachian Trail journey to FKT . He grubbed this down minutes, maybe even seconds, before heading to blaze.

Why eat before a workout? If you are eating on an empty stomach because you heard you would burn more fat you most certainly are cheating your workout and your body.   Working out on an empty stomach may  lead you down the path of a shorter workout time at lower intensity  than you liked simply because you don’t have the energy on board to do what your training plan is asking of you.

Eating a light snack before exercise maximizes your workout by providing quality energy to your body so you can complete all sets and reps in the gym or run your entire 5K loop in the appropriate heart rate zone.  Depending on how your body digests food, it is recommended to consume a high-carbohydrate snack 1-2 hours before exercise that is lower in total fat and protein.

Here are some rules of thumb to try and see if they work for you:

  • How much protein a pre-workout snack should have is dependent on how soon before your workout you plan to eat and whether or not you are doing a strength training work out or a more cardio workout:
    • If snacking three hours before your workout 7-15 grams of protein is about right. The shorter the amount of time between eating and your workout, the less protein you should consume and if you are eating a snack 30 minutes before a cardio workout you should be eating little to no protein. Save it for after your workout.
  • How many carbs? Carbs get your energy engine (muscles) up and running. If you are doing a one hour work out eat about 15-30 grams of carbohydrate 1-2 hours before. Organic Energy Food Oatmeal is a great choice here. If you are 30 minutes I out I would recommend Organic Energy Food Banana Mango Coconut
  • Should you avoid fat and fiber?  If your workout is lower intensity some folks can tolerate some fat, but if you are going hard you definitely what to limit the amount of fat you eat to as little as possible in the 1-3 hours before your workout. It will take longer for you to digest fat and having fat in your stomach during a high intensity workout could give some GI distress. Same thing goes for fiber: Keeping fiber under 3 -5 grams in a pre-workout foods eaten around the three hour mark is a good place to start. Everyone responds differently when it comes to digesting so you may be able to tolerate more or less than that amount.
  • Are there any micronutrients (e.g. calcium, potassium, sodium, etc.) that are important to get before a workout? In general micro nutrients should be coming from the foods you eat all day long to prevent inadequate consumption of any one nutrient to prevent deficiencies that in the long run will hurt both your health and your workouts. However, sodium which is the primary mineral lost in your sweat can give you a leg up on hydration. Sodium will not give you energy but it will help you with fluid absorption and retention, especially if you are a heavy sweater. CLIF SHOT electrolyte drink before your workout will give you three nutrients in one to support your efforts: carbohydrate, fluid, and sodium


Some people can eat a burger and hop on their bike while others need food to be totally digested before the can even think about exercise. Eating 1-2 hours of prior to your activity seems to work for most but, try out different timing and different foods to see what your stomach says are best.  Some pre-workout foods: half a whole wheat bagel with 1 tablespoon organic  peanut butter; CLIF Bar; 1 cup of nonfat yogurt with a banana; or 16-ounces of CLIF Electrolyte Drink.

Bottom line is to eat and/or drink something before you workout to improve the quality of your exercise!