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Exercising on an empty stomach, and dieting for goals

Exercising on an empty stomach, and dieting for goals
Within the fitness community, the debate on whether or not to exercise before or after eating has raged on for decades now, a question that's in the category of those that make something that should be simple, like dieting and exercising, feel like complicated arithmetic. And even those that claim to have the answer are just as divided as the average joe doing his research for the first time. Within the bodybuilding community, there's people that swear up and down on lifting before eating, but there's also other people who almost religiously take pre-workout protein shakes.  

To begin with, we'll talk about the theories behind exercising on an empty stomach. This theory comes from the line of thought based around that when you squeeze in a cardio session before eating, your body will naturally have to burn stored fat. 

This is based around the behavior of glycogen. Glycogen is a multi-branched polysaccharide of glucose, that serves as an energy storage in humans, animals, and, oddly enough, fungi. It is the main storage form of glucose in the body. And when you sleep, your body tends to, for lack of a better term, "run out" of it overnight, so when you wake up and hit the gym first thing in the a.m., the idea is that your body burns stored fats thanks to being low on carbs. 

But, without some sort of supplement to help you hold onto it, things get tricky when your body completely runs out of glycogen, in situations like an early dinner before a full night's rest in which you slept in a bit, the body may burn more muscle than you planned on losing for your weight cut. 

Despite that, there is still a rather staggering amount of benefits to skipping breakfast before your morning workout. 

The first one is that you burn fat faster. One study followed twelve active males who ran on the treadmill, either after breakfast or while they were still fasting from the night before.  The men who hadn't broken their fast, or hadn't eaten any breakfast, burned up to twenty percent more body fat during the same workouts! What's also interesting about this study is that the men who skipped breakfast didn't overeat later, or try to otherwise "make up" for the early morning calories they missed out on, which insinuates that getting a head start on your workout could help you lose more fat and keep you from trying to sneak in extra calories later. 

Another proven benefit of this method is the simply fact that time-restricted eating is a tried and true way to lose weight. Working out on an empty stomach certainly ties into the idea of time restricted eating. On diets of this vein, the general idea is to eat what you want, as long as it's relatively healthy, at certain times of day, with the biggest caveat is eating strictly between certain hours, with around twelve in between with no eating. This is because our body knows just when we're going to eat, so our hormones react by burning fat and facilitating weight loss during the foodless hours. Scheduling workouts during these fasting hours could encourage the body to burn even more fat, especially if you're exercising. 

The body's response to insulin is improved when you workout on an empty stomach. When we eat, our bodies release insulin to absorb all the nutrients in the foods we enjoy. But, when we're eating, too many carbs and sugar our bodies become insulin resistant, and it isn't able to do it's job as well. All that insulin builds up and can bring a wash of chronic diseases, such as diabetes. One of the many benefits of fasting, is reducing the sensitivity to insulin. Without a constant intake of food, insulin isn't created as often, so our bodies don't become immune to the hormone. 

Working out on an empty stomach may even inspire you to workout more. The stark reality of this day and age is that we're all very busy, but by working out in the morning before stopping to make breakfast, having that cup of coffee or whatever it may be, you can get your workout in early in the morning without the distractions that may derail you later in the day. 

And, finally, there's evidence that exercising when your carb intake levels are low, like when you're on an empty stomach before breakfast, actually helps improve performance during normal workouts. The idea between the train low compete high mindset is that working out in a glycogen-low state helps the body become more efficient at burning fat, so at times when carb levels are high the body is primed and ready to go. 

We should pivot here to talk about something mentioned earlier in the article, which is time restricted feeding. Diet-induced obesity is one of the biggest problems in the country today, and studies have now shown that it's not just the high fat diet we consume, but being allowed to eat frequently throughout the day and night and never disrupting that cycle. To test whether obesity and metabolic disease resulted from more the diet or the cycles, a study subjected mice to either round the clock availability or time restricted feeding for eight hours a day. Mice under the time restricted feeding consumed a similar amount of calories, yet were less likely to develop obesity, hyperinsulinemia, hepatic steatosis, and inflammation and have improved motor coordination. These changes in catabolic and anabolic pathways even altered liver metabolome and improved nutrient utilization and energy expenditure, proving that TRF is a valid strategy against obesity and associated diseases. 

So it's very valid to think of the two strategies combined, both the time restricted feeding, and the working out without eating are great ways to lose weight, and quickly. But one thing you may have to be wary is muscle loss due to lack of glucose. Thankfully, there are supplements that can be taken to lessen this impact. 

One of the best supplements I can recommend for a diet program like this is Sermorelin HGH. The most basic and obvious benefit it will provide is an icnrease in the amount of HGH produced, which will start your health improving in many various ways. Once sluggish metabolism starts to increase, and more energy and general stamina will fill your body. While sermorelin is not prescribed specifically for weight loss, through increasing your metabolism and the amount of HGH in your system it will yield some shockingly good results. 

Just to quickly review the benefits of Sermorelin, we'll go into a small aside here at the end of the article. Weight loss is all about fat burning, and if your HGH levels are low, your body is more inclined to hang on to fat as we get older, which is why we have a higher percentage of body fat to lean muscle, and this is because of the decrease in our HGH levels. 

By increasing the levels of human growth hormone in our systems, though, we convince our bodies that the extra fat storage that comes with age is unnecessary, and that fat should instead be burned for energy. And with this extra energy, more intense and frequent exercise can be had. And thanks to the increased levels of growth hormone in your system, you hang on to more muscle even during a period of extreme weight loss, allowing for more weight loss yet a better look thanks to the muscle mass you retain.  GH is even promoted by the low calorie diet, so this along with the supplement would provide a boost. 

But, like most things, working out on an empty stomach may not be the right move for everybody. One study published in the Journal of the International Society of Sports Nutrition may even suggest that there is no difference in weight loss between women who ate a meal replacement shake before exercising and women who ate nothing before their workout. 

Another issue is that without any fuel, you may not be working out as hard as you can. So while there are certainly benefits from not eating before you hit the road, a healthy mix of carbs, proteins, and fats may give you the energy you need for a harder work out. 

The extra energy you get from that small snack may actually be what you need, as intense workouts such as crossfit, tabata, or any other kind of High Intensity Interval Training workouts, also known as HIIT, burn quite a few more calories than the average day at the gym, and workouts for which you will want to have the maximum energy available to you. 

And if you're competing or training for endurance sports such as long distance raining, a triathlon, or something like boxing or fighting, working out on an empty stomach may work for a short sparring session or shorter distances, but you absolutely want to eat before going a full twelve rounds or several miles of running, and may even need to re fuel during the training session. 

And lastly for the against column, if you're someone who needs that mental net of knowing they aren't going to burn out mid-way through the workout, this may not be the best diet for you. This also goes for people who are diabetic, or have problems with low blood sugar that need to eat small snacks to stay safe. 

It would certainly be nice to tell people definitively that working out without eating will lead to better results no matter how you were built. But because of so many variables, like how fit someone may already be, what type of workout you're doing, it depends on your lifestyle and health history. 

The one crucial thing that everybody can do, though, is to stay hydrated and drink plenty of water before, during, and after every workout. Sometimes, even thirst is confused for hunger, so pounding a bottle or two of H2O may be able to keep your weight at bay. 

What may be just as important as what you eat during the workouts, is the meal you have afterwards. Consuming nutrients after you exercise is just as important as what you do, or don't, eat before it. 

To understand how the correct foods can help you after exercise, it's important to understand how your body is affected by working out. When you work out, as mentioned above, your muscles use up their glycogen stores. This results in your muscles being depleted of them, and causes them to get broken down and damaged. After your workout your body has to rebuild it's glycogen stores to repair and regrow this muscle proteins. Eating the right nutrients soon after you exercise can help you heal faster, and this process is served particularly well by carbs and protein to help decrease muscle protein break down, increase muscle protein synthesis and growth, restore your glycogen stores, and to enhance your recovery.  

The rate at which exercise triggers the breakdown of your muscle protein will certainly vary from person to person, and more importantly on the exercise itself and the level of training that you do. But even well trained and conditioned athletes experience the breakdown of muscle protein. 

Consuming a proper amount of protein after a workout gives your body the amount of amino acids it needs to repair and rebuild these muscle proteins. It also gives you the building blocks required to build new, bigger muscle. It's also recommended that you eat half to a full gram of protein per pound of body weight after you workout to facilitate muscle growth. Studies have also shown that ingesting twenty to forty grams of protein after exercise seems to maximize the body's ability to recover after the exercise. 

Your body uses it's glycogen stores as fuel during exercise, and eating carbs after your workout replenishes them. The rate at which these stores are used depends on the activity, such as long form workouts taking more of them than a short bout of resistance training. 

This is why that participants in endurance sports such as running, swimming, and combat sports may actually have to consume more carbs than a bodybuilder or football player. Eating plenty of carbs to rebuild your glycogen stores is most important for people who exercises regularly, such as multiple times in the same day. It's less important for people who have time for days off between each workout. 

Another popular misconception is that people think that eating fat after a workout slows down digestion and worsens the body's natural absorption of nutrients. While fat may slow down the absorption, that much is true, it will not affect the amount of nutrients your body absorbs. 

In one study, whole milk was shown to be more effective at promoting muscle growth after a workout than skim milk. Another study also showed that even when ingesting a high fat meal after working out, muscle glycogen synthesis was not affected. Some fat in your post workout meal may not affect your recovery, but it's also a good idea to still limit the amount of fat you eat after your exercise for your waist line's sake.

Another important and often looked over fact is that your body's ability to rebuild glycogen and protein is enhanced after a good workout, meaning that the timing of your post workout meal really matters. 

This is why it's recommended that you consume a good combination of carbs and protein as soon as you can when finished working out. And though the timing doesn't need to be exact, many experts recommend eating your post-workout meal within forty five minutes of finishing. It's also likely, according to some studies, that a pre workout meal may even have these same benefits if the exercise involved is going to be particularly strenuous.

And finally, no matter what your approach to dieting is be it post workout, pre workout, or time based fasting or not, it is important to stay plenty hydrated before during and after your workout.  When you are properly hydrated you ensure that the optimal internal environment and temperature is maintained for your boxy to maximize the results of it's workout. 

But during your workout, you will lose water and electrolytes through sweat. And when you replenish these after a workout you can help with recovery and performance. And it's especially to replenish fluids if you plan on working out again within the next twelve hours, and depending on the intensity of your workout, water or an electrolyte drink are recommended to replenish fluid losses. 

All in all, it's important to consume a proper amount of carbs and protein when it comes to exercise. It stimulates muscle protein synthesis, improves recovery, and enhances your performance during your next workout. 

And if you plan on doing a time restricted feeding type diet, and want to take extra supplements in the vein of sermorelin acetate, make sure to consult with a physician regarding this before starting any program. 

About the author

Dr. Constance Odom, MD

6 min read