Phoenix Ignition Fitness Company

Fitness by the Fire: Fuel for Training and what to eat for performance

by Ron Kennedy • February 26, 2019
Proper nutrition is a pinnacle of a successful fitness program. Regardless if your ultimate goal is weight loss, lean muscle mass building, or a sport specific activity or event such a marathon or a softball league, what you eat directly impacts the moments before, during, and after the activity has taken place. You often hear that breakfast is the most important meal of the day, and though there is significant truth to that, the phrase was coined from the concept of fueling up before going to work or school for the day so you can energy to last through out. It is a very good idea to fuel your metabolism first thing in the morning, as if you have been conditioning your metabolism properly, all through the night you have been burning calories and your body should need to restock the pond, but what about what you ingest right before exercise?

Despite what results scientific research has yielded over the years, individuals have varying opinions of “what works for them” as opposed to what actually works. I have been a fitness professional for over 16 years, and I have seen clients try to complete complicated strength training routines on empty stomachs as well as quite literally finishing eating the moment before we begin to exercise. With this article I will present both points of view, the effects it will have short and long term, as well as my own personal preferences of what and when to eat in correlation to exercise.

Empty Stomach:

It is completely understandable if you prefer to exercise on an empty stomach. I work with several clients who exercise very early in the morning before work begins, and it is difficult enough to get up at 5:00 am, let alone fill your belly, get the gym and train like a movie star. When you exercise with a full stomach you feel the solids breaking down into liquids, the gases gathering and rolling around, and often times higher intensity training causes feeling of nausea. No one enjoys those sensations, and it makes it very difficult to concentrate on isolated muscular contractions. Though there are often unseen benefits to pushing yourself to perform without any fuel.

When you eat a meal, especially a meal containing a good amount of carbohydrates, your body releases insulin. Insulin is a hormone that helps regulate blood sugar, and prevents the body from having too high of levels of blood sugar which is toxic to humans and eventually kill you. Though insulin is vital to our survival, it also is a hormone that aids in storing fat. That said, the time directly after you eat your body is working to STORE fat not burn it! It doesn’t matter if you are a 90 year old taking the dog for a walk or a professional football player completing a 500lb squat, you will not be able to burn body fat until your insulin levels drop. This is very discouraging to fitness enthusiasts who’s focus is weight loss. After all, who wants to come to the gym and push themselves if all their efforts are not going towards burning fat… at least at the time, but more on that later. It could be argued that if you are trying to lose weight, you need to exercise on an empty stomach, but what about the cons?

Obviously, unless you are accustomed to training on an empty stomach, you are going to struggle when your energy levels run and low, and they will eventually run out. This might be acceptable for just a brisk walk, or 30 minutes on the cross trainer, but what about seriously pushing yourself? This is especially important if you are working with a professional with a sinister laugh, who purposely enjoys your torment just so you can shut him up by pushing yourself to your limits and overcoming the challenges he has laid before you (no names mentioned of course J). Energy is necessary for endurance conditioning, despite the fact your insulin levels will prevent you from burning fat temporarily. When a prospective client contacts us, I mention several times to not come in on an empty stomach as doing so and exercising lowers blood sugar levels to the point of feeling faint and the urge to vomit. Not to mention if your plan is to exercise for an hour with a fitness professional, why would you want to spend half of that time seating down and recovering because your energy levels are so low?

Eating before exercise:

The most obvious benefit to eating before you exercise is having fuel on standby. Endurance regarding performance is the cornerstone of the science we use when working with our fitness training clients, and it is very difficult to maintain endurance without energy. Numerous times my own workouts have been cut short due to hunger pains taking me away from the focus I require to push myself through higher level training protocols. Many people believe a good source of protein is the “go too” for pre-workout meals, but protein is not the most important food source to ingest before training, carbohydrates are.


Carbohydrates are one of your body’s best sources of fuel due to their reaction to oxygen. In fact, they use less oxygen for every kilocalorie of energy produced than either fats or proteins, which make them an important part of your diet if you are physically active, especially if your activities involve endurance-based movements. How does your body react to carbohydrates during exercise you ask?

The glycogen stores in your liver and muscle groups depend on your carbohydrate intake. Your body converts glycogen to glucose (a type of sugar), which your muscles use as a primary source of fuel during exercise. This means that your ability to exercise is limited by the amount of glucose in your body. After about 90 minutes of exercise, your body’s supply of glycogen is completely depleted, which puts you at a risk for “hitting the wall” or feeling lethargic during your endurance event. If your body doesn’t have enough glycogen to sustain you, it will start to burn fat for energy. Fat burns at a much slower rate than carbohydrates, and though helpful for weight loss programs, ultimately this will slow you down. All the more reason to eat some healthy carbs before working out!


Proteins are all about recovery. Most of you reading this have been present to hear me grip about the last few sips of a strong post-workout protein shake. That watery thick mixture of chunks of powder combined with now luke-warm water… the worst substance on earth! There is a reason why I put myself through that experience day after day. To repair muscle damage, your body needs protein, which is made up of amino acids, the building blocks for your muscles. An adequate supply of protein will help your muscles recover from workout stress, especially if you engage in weight-bearing exercise, such as strength training or jogging. Including some protein in your pre-workout meal may help reduce post-exercise muscle soreness, and it is mandatory to feed the muscles the nutrients it they need to grow.


Many people try to limit the amount of fat in their diet but cutting it out completely can actually hinder athletic performance as well. Fat does provide fuel for the body. If your workouts typically last more than an hour, your body uses fats for energy after your glucose supply has been depleted. However, you should keep in mind that some fats are more beneficial for people than others. Studies show that saturated and trans fats raise total blood cholesterol levels and low-density lipoprotein (LDL), or your “bad” cholesterol levels.  However, monounsaturated and polyunsaturated fats, found in many plant-based foods and oils, play a critical role in your body by helping to regulate oxygen, hormone restoration, cardiovascular health, and immune system integrity.

My opinion:

Though I acknowledge the benefit of using insulin levels to speed up the fat burning process, my body does not operate the same without food, especially in the gym. Don’t get me wrong, there are certainly limits as to what and how much food I will consume before training. Ask me about the time I ate a massive bowl of fettucine alfredo with chicken and half of a loaf of Italian bread, before completing a leg day that has been dubbed “The gauntlet” … until that day, I didn’t realize you could vomit in technicolor. Over eating is never suggested, especially before exercise, but trying to generate enough strength to consistently push the maximum volume of strength for your muscles without energy is too difficult for me. Early morning cardiovascular training is my one exception, since doing cardio on an empty stomach first thing in the morning does significantly promote fat loss. Yet, those sessions have always been limited to 30 minutes, and I ate immediately afterwards.

I have also watched clients attempt to perform on empty stomachs. Yes, it can be done, but time and time again these same clients start looking at the clock 20 minutes into our appointment hoping there are only a few moments left until the end. To make matters worse, their form, strength levels, and over all endurance are drastically impacted 1/3 through our session to the point where they will only perform at about 50% of their potential. Yes, you could argue that the solution is just to reduce workout time, but if the goal is to maximize your athletic performance, why would you consider minimizing your time?

It’s OK to not eat before you exercise but realize that you are putting yourself at a significant disadvantage to those who have properly fueled up. If you are still dead set to push yourself to high levels of exercise without food, please limit your time and activity to mainly cardiovascular conditioning and try to keep under the 30-minute mark. If your body is telling you it needs something more than your undying well to keep going, I suggest you listen to it, and eat appropriately.