Back to Basics: Fueling Your Workout

Proteins, fats, carbs, before, after, powders, shakes: What do I eat when?! With so much pushing about supplements and the thousands of new diet plans, it’s easy to forget that our bodies are perfectly capable of being healthy and happy on their own, so long as we treat them well. Read ahead to get back to the basics of nutrition and how to fuel your workouts!

When approaching nutrition, there are two main categories of food: Macronutrients and Micronutrients, simply named for the amounts required in our diets. Macronutrients are needed in large amounts to sustain and fuel an organism, whereas micronutrients are only needed in trace amounts to support normal growth and development. This piece will focus on macronutrients as they are the key players in energy production. The three groups of Macronutrients are Carbohydrates, Fats, and Proteins.

When looking at how nutrition fuels our bodies, we first have to do a little review of bioenergetics. Bioenergetics is the transformation of energy within a system, meaning how the food we eat is broken down and used to produce energy. Remember all that stuff from biology about ATP, the Kreb’s Cycle, and glycolysis? Well, for now we’re just going to stick with the two key takeaways: the chemical reaction that breaks food down into energy can be either anaerobic [no oxygen is used] or aerobic [oxygen is used], and which type of reaction takes place is dependent on the duration and intensity of the exercise.

If you need a refresher on anaerobic vs aerobic exercises, check out my post Anatomy of a Workout!

The duration and intensity of an exercise, and therefore the chemical reaction taking place, also determines which macronutrient will be used in the production of energy-we can go more into biochemistry and energy systems later, just remember that the food we consume will be broken down and eventually result in two molecules, ATP and ADP, that act as chemical batteries to power our movements.

Carbohydrates are our primary fuel for all activity. When we eat carbohydrates, we are consuming glucose, which is stored in muscle tissue and the liver as glycogen. When energy is required, or blood sugar levels are low, this glycogen is taken out of storage and transformed back into glucose by a process called glycogenolysis. This glucose is what is used when producing ATP [energy]. Because carbohydrates are the primary fuel, this is why “carb loading” has become a popular tactic, as it enhances the muscle mass storage of glycogen, and therefore, the amount of glucose that can be used to produce energy. [Note, carbohydrates are the only macronutrient that can be used to produce energy without oxygen! This means they can burned either anaerobically or aerobically.]

The next favorite fuel to produce energy are fats. Fats often get a bad reputation as something harmful that must be avoided. This is imply not so. While it’s true, an unhealthy amount of the wrong kinds of fats can result in heart disease, stroke, cancer, and clots from cholesterol, healthy fats also have a very important role. Remember, everything in moderation! Fats act as our body’s insulation system and are key in transporting vitamins and minerals. Fats- triglycerides- are broken down and either burned as energy or stored in fat cells known as adipocytes. Just like how glycogenolysis transformed stored glucogen into it’s usable form of glucose to produce energy, fat undergoes it’s own transformation. Through a process called beta oxidation reaction, the fatty acids are converted into a usable form to produce energy. This means that the utilization of fats requires oxygen so it’s what? Yes, aerobic! Therefore, burning fat usually kicks in 15-20 minutes into aerobic exercise.

Finally, there are proteins, the seemingly most misrepresented macronutrient, in my opinion. Maybe it’s because everyone associates proteins with muscles, but I’ve heard a lot of things along the lines of “I want to build big muscles, and protein builds muscle, so I must have to eat a lot of protein before my workout!” Even if you’ve already forgotten everything else on this page, commit this to memory: Protein will not fuel your workout! Yes, protein-amino acids-are the building blocks of muscle, but that has nothing to do with producing energy to efficiently complete a workout. Protein will only ever be broken down to produce signficant energy in extreme conditions, such as starvation. Under normal circumstances though, the catobolism of proteins is too energy inefficient and accounts for only 5% of the body’s energy needs. Protein’s shining moment comes post-workout. During intense exercise, the muscle fibers are damaged and this microtrauma activates the body’s self-repairing mechanisms, wherein the amino acids in protein repair the fibers, building the muscle back up bigger and stronger!

When assessing your nutrition, a healthy portion of macronutrients is 50-60% carbohydrates, 20-30% fats, and 10-15% proteins.

In addition to proportions, the timing of what you eat can also influence your workout! Remember that everyone is different and may have their own preferences, some may be able to workout on nothing in their system while others prefer to have a light snack right before working out. These are general guidelines for planning your pre and post meals!

We know that carbohydrates are the first macronutrient to be used for energy production, so they should also be our primary objective when gearing up to train. 3-4 hours before your activity, have a nice meal of healthy carbs, such as oatmeal or peanut butter banana toast for breakfast, or some light pasta for lunch to enhance the glycogen storage in your muscles. An hour before working out, if you feel you need it, treat yourself to a high glycemic index snack. My go-to is a handful of trailmix, or if I haven’t eaten in a long time, half a peanut butter sandwich.

If you’re planning on participating in an activity for longer than 90 minutes, plan some snacks! 70 grams of carbs per 1 hour of exercise is the recommended amount, just be sure that it is something easily digestible and easy on your stomach-nothing greasy or heavy!

After a workout, consume a combination of carbohydrates and proteins. This will help replenish what you’ve burned and rebuild muscle. If you’re looking to get specific, a 4:1 ration of carbs to proteins is recommended, but any clean, well balanced meal will do it!

While micronutrients aren’t a huge player in actually fueling a workout, they do have some vital roles in training and performance. Micronutrients are our vitamins and minerals that we consume in trace amounts. Below are the most important micronutrients for supporting our bodies during training and their functions:


  • Vitamin A- aids in growth and repair of tissue
  • Vitamin C- used in cell development
  • Vitamin D- Facilitates calcium absorption to aid in bone development


  • Iron- Maintains regular Red Blood Cell functioning, which is how oxygen is transported
  • Calcium- Bone tissue health
  • Magnesium-Skeletal and connective tissue maintenance
  • Sodium/Potassium- Aids in fluid transport

Hope this helped you to get back to the basics of your workout nutrition, and maybe provided some more insight on how our food is transformed into energy! Be sure to drop a comment or message if you have questions or read something you want to learn more about!
Happy eating!

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