Intermittent fasting has become quite popular in the fitness world, and many people have started training while fasted due to the supposed benefits.
If you’re one of those people who train fasted and are wondering whether pre-workouts break a fast, we have the answer: it depends on the ingredients in your pre-workout supplement.
Does pre-workout break a fast? If your pre-workout contains calories from BCAAs or EAAs, it will definitely break your fast. However, keep in mind that many low-quality fitness supplements may not have accurate labels (Rarely do supplements like pre-workout display calorie content on the labels; you will mostly find only the ingredients listed), as FDA approval is not required for selling fitness supplements.
There are various pre-workouts on the market that contain anywhere from 0 to 300 calories per scoop. Since our primary concern is avoiding a significant spike in blood sugar that would break the fast, it’s advisable to opt for pre-workout supplements with zero or very low-calorie content.
Let’s explore this topic further to find out whether taking pre-workouts breaks a fast.
Does Pre-Workout Break a Fast
The primary ingredients in pre-workouts typically include (but are not limited to): caffeine, beta-alanine, BCAAs, EAAs, L-citrulline, taurine, artificial sweeteners and flavors, and sometimes sugars and carbs.
These are a lot of ingredients, and some pre-workouts may contain even more, like creatine, alpha-GPC, and others. It’s important to stay mindful of the ingredient list, as some of these contain calories, which will definitely break a fast, while the majority are safe for consumption.
Before we discuss each ingredient and evaluate whether they contribute to breaking a fast, let’s first do a brief overview of pre-workouts, fasting, its benefits, and effectiveness, along with the role of fasted workouts.
How does Pre-Workout Work?
Pre-workouts are fitness supplements specifically designed to be taken before starting your workout. They contain several ingredients that can help improve your performance during exercise, such as enhancing focus, alertness, athletic performance, and endurance.
Caffeine is arguably the primary ingredient in pre-workouts, as it can maximize your output during workouts, increase focus, and make the overall experience more enjoyable.
What is Intermittent Fasting?
Fasting is a voluntary abstinence from food. There are numerous benefits to fasting, such as improving metabolism and aiding psychological health. Fasting is great for reducing overall body fat, but it should be done in moderation.
There are different levels of fasting, like 12 hours, 24 hours, 36 hours, or even longer. People who are physically active during the week, such as those who run, train, lift weights, practice martial arts, or engage in other fitness activities, should be cautious and control their fasts. When you’re physically active, it’s not advisable to go long periods without eating.
In earlier times, humans often went days without food, as they had to hunt for it. Many consider fasting to be our natural state and believe it fosters a healthy relationship with food.
For example, when you don’t eat for a day, your body begins to burn fat (ketosis) instead of sugar (glycolysis), which can effectively reduce body fat and improve your appearance.
Today, we see that top-performing athletes in fields like boxing, weightlifting, football, tennis, swimming, and other sports rarely, if ever, practice consistent fasting. Prolonged intermittent fasting can decrease energy levels and lead to muscle loss.
While this is true, it doesn’t mean we can’t learn from our ancestors. Fasting can definitely be beneficial if done in moderation and utilized in the right way.
What Breaks a Fast and What Doesn’t?
Your blood glucose is the main indicator of whether your body is in a fasted or fed state. To determine exactly what breaks your fast, you would need to wear a blood glucose monitor to track what’s happening.
According to scientific literature, drinking water, black coffee, or tea will not break your fast. Consuming caffeine in pill form or fitness supplements (assuming they only contain caffeine) also won’t break your fast.
Fasting is highly contextual. For example, if you’re in a deep fasting state (e.g., 24 hours), eating a single peanut or a handful of nuts may not break your fast. However, if you’ve just started fasting an hour after consuming a large meal full of protein and carbs, eating even a single peanut could break your fast.
The general rule to avoid breaking a fast is to avoid sugar. To illustrate, even ingesting a gram of sugar can disrupt some of the receptors responsible for fasting.
Since fats don’t trigger the same receptors as sugar, many people consume things like MCT oil, claiming it doesn’t break their fast. The reasoning is that fat doesn’t raise blood glucose like carbohydrates, and protein has an intermediate effect.
It’s challenging to definitively say which foods break a fast and which don’t in small amounts. In large amounts, it’s easier to determine. For instance, if you’ve just run an ultra-marathon and drink a can of soda, it may not break your fast. However, if you drink the same soda in a rested state, it likely will, as would eating a slice of pizza.
Ultimately, to determine whether eating something or taking pre-workout breaks your fast, you need to consider when you last ate, what you ate, and your activity level during this time.
Unless you are consistently wearing a glucose monitor, the key to a successful fast is to stay as strict as possible and limit your food intake as much as you can.
Do Pre-Workouts Break a Fast?
Taking into account what we have discussed, we need to factor in a few things before concluding whether taking pre-workouts will break your fast.
First of all, you will need to carefully read the label of your pre-workout and pay attention to the ingredient list. As mentioned earlier, pre-workout supplements typically list the ingredients, but rarely provide detailed nutritional information per scoop.
You might think that the supplement has zero calories, but this is mostly not true. If your pre-workout contains essential amino acids like EAAs or BCAAs, it most likely contains calories. Depending on the full ingredient list, one scoop of pre-workout can have between 20-50 calories.
Whether this is enough to break your fast is hard to say, as it depends on many factors, such as how many hours have passed since you started fasting, what your last meal was, your physical activity during this period, and where you are within your circadian rhythm.
So, what’s the solution to avoiding breaking a fast while taking a pre-workout supplement? First, pay close attention to the ingredient list and know what to look for. For example, ingredients like caffeine, creatine, taurine, L-citrulline, electrolytes, and vitamins like B12, C, and B3 typically contain zero calories.
It’s best to avoid pre-workout supplements that contain numerous ingredients, especially those with carbohydrates, sugars, artificial sweeteners (While artificial sweeteners don’t directly contain carbs, their impact on blood glucose and insulin sensitivity is worthy of attention), and coloring, as these products can negatively impact your progress.
Finally, always purchase your supplements from a reliable manufacturer and brand, as some products may contain undisclosed ingredients that aren’t listed on the label. Be mindful of what you’re buying for the sake of your health and progress.
Intermittent Fasting-Friendly Pre-Workout Ingredients
Let’s discuss the ideal pre-workout supplement with the best ingredients that are intermittent fasting-friendly and will perfectly complement your fitness goals.
- Caffeine: Caffeine contains zero to very few calories and is the driving force of pre-workout supplements. It acts as a stimulant that enhances focus, alertness, and energy levels. Caffeine improves exercise performance by reducing perceived effort and fatigue.
- Creatine: Creatine is one of the most well-researched and extensively studied fitness supplements. It enhances strength, endurance, muscle mass, and athletic performance. Creatine does not affect blood glucose or insulin levels, has zero calories, and is fasting-friendly.
- Taurine: Taurine is a well-researched, semi-essential amino acid beneficial for cardiovascular health. It enhances exercise performance and recovery. One gram of taurine contains zero calories, making it a great addition to pre-workout supplements.
- L-Citrulline: L-Citrulline boosts endurance, reduces muscle soreness, and does not impact blood glucose levels, all while containing zero calories.
- Electrolytes: Electrolytes like sodium, potassium, and magnesium are vital for muscle contractions and preventing dehydration and muscle cramps during intense workouts. Like other fasting-friendly ingredients, electrolytes do not affect blood glucose levels.
- Vitamins: Vitamin B12 is crucial for metabolism and red blood cell production. Vitamin C supports immune function and collagen synthesis, while Vitamin B3 improves blood circulation and plays a key role in energy metabolism.
People who regularly take pre-workouts—most of them, at least—consider caffeine the key ingredient, as it is what makes the whole workout session enjoyable. Since each scoop of pre-workout contains around 150 mg to 300 mg of caffeine, some people opt to drink a cup of strong black coffee and avoid fitness supplements.
However, if you find a good pre-workout supplement that contains clean ingredients, as mentioned here, there will be zero problems with breaking your fast, as a pre-workout with a similar ingredient list will contain zero calories.
So, try to look for fasting-friendly pre-workout supplements with a clean ingredient list that will allow you to get the most out of your workout without compromising your fasted state.
The Goal of Fasted Workouts
One of the primary reasons why people work out in a fasted state and are cautious about consuming anything that might break it is the state of ketosis. In ketosis, your body burns fat instead of glucose, which is ideal for people who want to lose weight and decrease their overall body fat.
There are additional benefits to fasting that can be psychological and related to detoxification, as fasting promotes the activity of certain enzymes involved in detoxification.
If you are someone who regularly trains in a fasted state and wants to maintain this practice while taking pre-workout supplements, make sure to choose ethical products that are fasting-friendly and manufactured by reputable brands or sellers.
Benefits of Fasting
Fasting is healthy if done in moderation. When you fast for 16 hours or more, your body will start a cellular cleanup process. Autophagy breaks down damaged cellular components and repurposes them to produce energy and create new proteins.
Fasting helps with weight loss and reduces inflammation. You will noticeably reduce your overall body fat, as working out in a fasted state—whether it is cardio, strength training, HIIT, or anything else—burns actual fat while you are in a state of ketosis.
Furthermore, fasting combats metabolic inflammation. It increases arachidonic acid in your blood, which is known to inhibit inflammation.
Fasting affects your hormones, cells, and genes. For example, fasting promotes human growth hormone activity, decreases insulin levels, and improves cellular repair.
On the surface, fasting might seem simple, but it promotes a lot of activity in our bodies that can ultimately benefit our overall health and well-being.
David Sinclair, a Harvard genetic professor, believes that fasting plays a significant role in anti-aging. Fasting for 16 to 18 hours can positively impact your health in a meaningful way, but it’s important to limit it and not use it every day.
The frequency of fasting—whether it’s a few times a week or month—depends on your body and how you feel, as experiences vary from person to person. What works for one individual may not be suitable for another.
If you’re looking to incorporate fasting into your lifestyle, start slowly and assess your comfort level. Pay attention to how it affects your daily life, workouts, and work.
Conclusion
Lastly, does pre-workout break a fast? Whether a pre-workout supplement breaks your fast depends on its ingredients. Supplements containing BCAAs, EAAs, sugars, artificial sweeteners, or hidden ingredients not listed on the label can definitely break your fast.
Generally speaking, it’s difficult to determine the exact amount of food needed to spike blood glucose and break your fast. Numerous factors play an important role, such as when you last ate, what you ate, and your activity level during that time.
All things considered, for the best results, it’s practical to stay as strict as possible with your fast. When shopping for pre-workout supplements, try to buy products from reliable manufacturers and brands, and pay close attention to the labels and ingredient lists to ensure what you are buying is indeed fasting-friendly.