What Exactly is a “Fasted Workout”?
Technically, the term is “fasted cardio” and refers to any form of aerobic exercise performed while in a fasted state. In other words, any cardio exercises performed 10-12 hours after eating is considered a “fasted workout”. Reading in between the lines and assuming you don’t unsafely skip meals, that means exercising in the morning before having breakfast. But, does fasted workout help with fat loss or just another gimmick diet strategy?
Does Fasted Cardio Actually Increase Fat Burning?
Exercising on an empty stomach first thing in the morning probably doesn’t sound all that appealing to many. But, if it does actually increase fat burning, perhaps people might reconsider. So, does fasted workout help with fat loss or just more hype to ignore? Let’s look at the science behind weight loss for the answer.
At it’s most basic, losing weight boils down to creating a sustained caloric deficit. Or, simply taking in fewer calories than we burn. And conversely, gaining weight happens when we ingest more calories than we burn causing the body to store the excess calories as fat for later use.
More specifically, the human body generates energy through a combination of things, including:
- Burning glycogen which is a carbohydrate found in liver and muscle tissue
- Blood sugar already present in system from foods we just ate
- Stored fat burning
More intense workouts tend to burn blood sugar for energy. Lower intensity exercises and activity typically burn stored fat to generate energy. So, swimming some laps at the gym burns stored fat. On the other hand, HIIT more likely burns blood sugar to produce the necessary energy.
So, the big idea behind fasted workouts is they force your body to burn stored fat for energy since you are exercising on an empty stomach. But, as we just learned, cardio exercise typically burns stored fat anyway.
So, fasted cardio definitely burns stored fat. But does it help us reach our weight loss goals faster or not.
Effectiveness of Fasted Cardio on Fat Burning
In the short term, fasted cardio helps shed some unwanted pounds. However, fasted cardio needs restricted to low intensity aerobic exercise only. For any form of HIIT, exercising on an empty stomach means lower blood sugar levels. Simply put, fasted cardio won’t provide your body with enough energy to hit peak caloric burn like you can with anaerobic and high intensity exercises.
Simply put: Fasted cardio is a gimmick if you are looking for long-term, sustained fat burning and weight loss. The body already burns fat stores during cardio anyway. Plus, any effective fat burning and sustained weight loss requires a balance between anaerobic and aerobic exercise combined with a healthy diet.
So, does fasted workout help with fat loss? Technically, yes. However, there are no conclusive studies or evidence that it significantly increases fat burning. In addition, fasted cardio limits you to aerobic exercise and leads to low blood sugar levels that can be dangerous for some people depending on health condition.
For long-term weight loss and accelerated fat burning, you need to boost metabolism rate naturally.
Best Thing to Boost Your Metabolism Naturally
Many dietary supplements formulated with high doses of caffeine and other stimulants can temporarily boost metabolism rate. In the long run, artificially increasing metabolism rate both backfires and causes more problems than it solves. The inevitable plateau most people reach on dietary supplements happens when the body adjusts the metabolism rate lower to compensate for the artificial increase.
The best thing to boost your metabolism naturally to increase fat loss is simply eat more protein. Eating protein helps increase fat burning in 2 significant ways:
Protein Naturally Boosts Metabolism Rate
To process and digest protein, the body burns 5-10X’s more calories than carbs or fats. According to some studies, the body burns 30% of all calories it derives from protein. So for every 100 calories of protein you eat, only 70 are available for use after digestion.
Protein is Building Block for Lean Muscle Mass
The more fat cells you have in your body, the lower your baseline metabolism rate. Conversely, the more muscle cells you have, the higher your baseline metabolism rate. Basically, muscle cells require more energy to maintain than fat cells. Protein helps build lean muscle mass faster and ultimately elevate your metabolism rate naturally for sustained fat burning.
Now we return to the question of “Does fasted workout help with fat loss?” Since fasting reduces blood sugar levels necessary for high intensity exercise like weight lifting, cycling, and HIIT, then it limits your ability to build lean muscle mass. In that sense, a fasted workout actually impedes upon weight loss.
Other Benefits of Protein for Burning Fat
Getting 25-30% of total caloric intake from protein each day helps you achieve a sustained caloric deficit. Studies show that total caloric intake drops by up to 430 calories per day with no special dieting or exercise required. Depending on the exercise, that’s roughly the amount of calories you can burn after an hour of working out!
In addition, protein helps naturally curb cravings. This is because ingesting protein affects the release of satiation hormones for up to 12+ hours after we eat. Simply eating a high protein breakfast like eggs can lower late night cravings by up to 50%.
Other Options to Boost Metabolism Naturally
You do want to avoid weight loss supplements that artificially boost metabolism. However, the best boost metabolism pills do so naturally by helping reverse leptin resistance.
Leptin is a metabolic hormone that regulates food intake. When we eat, leptin levels increase and this triggers the brain to release satiation hormones so we stop eating. When we don’t eat, leptin levels decrease and the brain triggers cravings so we ingest calories. If the brain properly detects leptin, losing weight is 100% natural.
Unfortunately, leptin resistance occurs when the brain stops detecting the metabolic hormone properly. When that happens, the brain thinks the body’s fat reserves are gone and that you are starving. This triggers three responses that cause us to gain weight and doom diets to failure:
- Cravings increase in intensity and frequency
- We need to eat more to feel satiated
- Metabolism rate decreases to conserve energy
So, ideally, you want weight loss supplements that rebalance metabolic hormones and help reverse leptin resistance. In doing so, cravings disappear, portion sizes decrease, and metabolism naturally increases.
Avoid fasted cardio for long term fat burning and weight loss. All cardio will burn stored fat. However, exercising on an empty stomach lowers blood sugar levels making anaerobic exercise less effective.
For long term fat burning and weight loss success, you need to increase lean muscle mass, eat more protein, and incorporate both aerobic and anaerobic exercise into your daily routine.
Mike Dorfman is BS in Biochemistry from the University of Colorado. Mike’s has worked as a personal trainer for Gold’s Gym and helped many clients achieve their weight-loss and fitness goals.
To health first, weight-loss second. Mike and Tetrogen are here to help you make the transition to the healthier, happier, and thinner you!