We all know that working out on an empty stomach is a big factor when it comes to burning fat, fasted cardio has been a popular method for years and is based around the idea that you will tap into your fat stores as a priority for energy when you do this.
When it comes to lifting weights however then there is a stark contrast of opinions with many believing that you need to fuel the muscles prior to training with an adequate supply of carbohydrates and proteins.
As it stands there is no optimal time that you should be working out, the majority believe that afternoon workouts are best however the real reason that you might want an answer to this is because lifestyle choices (work, family etc.) mean that in order to train it needs to be the first thing in the morning.
Working out on an empty stomach bodybuilding? There is no defining research to show that working out on an empty stomach when bodybuilding will result in any form of negative progress and that it will in fact come down to individual characteristics for performance. The most important factor is how quickly you can tap into your CNS.
Whilst many believe that a lack of nutrition and an empty stomach will lead to poor performance in the gym and slower progress over time as a result the key component will actually be how quickly you can get your central nervous system operating at full capacity.
Working out on an Empty Stomach Bodybuilding
Some will say that it comes down to preference when working out on an empty stomach when bodybuilding. For some a good pre workout or caffeine boost from a cup of coffee is enough to get you firing in the gym.
If you don’t see any drop in performance and can still get stronger over time then there is no reason for you not to carry on with this method. For some however, working out on an empty stomach can lead to a reduced performance in the gym.
Is it ok to workout on an empty stomach when bodybuilding? When it comes to working out on an empty stomach when bodybuilding the answer is of course that it’s ok if this is what fits your lifestyle. Whether it is optimal is another topic for discussion but in terms of can you do it and still see progress, the answer to that is yes you can.
Will You Lose Muscle If You Workout on an Empty Stomach
Something that is of a larger concern when it comes to working out on an empty stomach is whether you will lose muscle as a result. The thought process here is that without sufficient calories in place to fuel a workout then you will start to eat into the muscle tissue to use as energy.
This however is a very short sighted view and is brought about more from supplement companies pushing you to consume protein and carb sources every few hours rather than hard fact studies around the subject.
In terms of protein synthesis (the hormonal process of building muscle), whenever you lift weights and create active tension against a load then this will create metabolic stress and kick start the process of protein synthesis.
It’s important to note however that lifting weights by nature is a catabolic process which means that it breaks down muscle tissue. Lifting weights causes microscopic tears to the muscles and puts them under stress which by nature is a catabolic process.
It’s only after a workout (though the process can occur during a workout) that protein synthesis is activated and you can start the muscle building process which is why your daily nutrition and rest/recovery protocols are more important for building muscle than the actual workout itself.
The key point to note is to ensure that you are hitting your daily protein targets, a good guideline to follow is a minimum of 1g of protein per 1lb body weight. This could also be more accurately defined as 1g of protein per 1lb of lean muscle mass however this is much harder to calculate.
Therefore is you are a 200lb individual you should consume roughly 200g of protein per day. As long as you are consuming enough protein on a daily basis to support the process of protein synthesis then you won’t lose muscle mass even when training on an empty stomach.
It is only through sustained and prolonged periods of fasting will you see the issue of muscle degradation as a result of protein catabolism and will occur as a result of depleted liver glycogen.(source)
Does Working out on an Empty Stomach Burn Muscle
Following on from the last point it’s also assumed that working out on an empty stomach will burn muscle because there is not enough glycogen storage available in order to fuel a workout.
Whilst it’s true that during sleep in a fasted state you do deplete glycogen stores (one of the reasons your muscles look flatter in the morning upon waking) there is a significant difference between depleting and emptying.
During a fasted workout you will still have energy stores from which to provide energy, these just won’t be optimal for a high intensity training session and you may struggle to feel a great pump and muscular contraction on lower levels of carbs.
Consuming a carb heavy meal the night before however is an easy way to combat this and will ensure more than enough carbs are available within the body to support a workout on an empty stomach.
To burn muscle on an empty stomach is a ridiculous phrase that is backed up with no scientific studies whatsoever.
Is It Ok to Lift Weights on an Empty Stomach
When lifting weights on an empty stomach something that is far more relevant and likely than burning or losing muscle is your actual performance in the gym. I’ve discussed the availability of carbs and glycogen to fuel the workout however another important factor to consider is the nervous system.
Whilst muscular contractions are usually the focus of a weightlifting session they are not the only influence on performance. Your nervous system actually sends signalling to the muscles to maximally recruit muscle fibres.
It’s why you see powerlifters warming up with just the bar. For many at an elite level it might feel like lifting up a broomstick however the purpose of this is to prime the nervous system and ensure the correct motor mechanics are in place before increasing the weight and loading the muscles.
This is one area where many will differ based on their genetics. It’s very much true that some people function better in the morning and some function better at night due to their biological makeup. Therefore if in general it takes longer for you to get going in the morning then workouts are not best for you, empty stomach or not.
This is therefore something that you definitely need to keep in mind when considering working out on an empty stomach as a lack of food might not be the only thing that holds you back during a workout.
Pros and Cons of Working out on an Empty Stomach
When it comes to working out on an empty stomach there are of course pros and cons of this approach, as with any training approach that you decide to use. If there was one universal training program that optimally built muscle and burned body fat then everyone would be doing it.
For now however you need to weigh up the pros and cons of any approach that you take.
Pros of Working out on an Empty Stomach
The main benefit of working out on an empty stomach is the potential fat burning benefits that will come from potentially tapping into fat storage for energy when glycogen stores are low.
This is not a guaranteed scenario so don’t suddenly start training on an empty stomach in a bid to try and torch the body fat but it is worth testing out to see how you respond to this type of workout.
It’s true that some will easily tap into their fat stores more than others will to utilize energy but it could be that you end up depleting your glycogen stores even further which will negatively impact your training session when it comes to lifting weights.
Cons of Working out on an Empty Stomach
It’s true that the potential cons of working out on an empty stomach are far greater than the pros. A depleted glycogen store could mean that muscular contractions and energy levels are sub optimal meaning that your sessions don’t have the same level of intensity as they do on a full stomach with high energy.
There is also the issue that working out on an empty stomach (assuming you are training early in the morning) is that your CNS will not be firing at optimal levels. As mentioned earlier an engaged and active nervous system contributes massively to recruiting muscle fibres and lifting maximal loads.
If you don’t train particularly heavy then this should be too much of an issue however any training above 80% of your 1 rep max will likely suffer if your CNS is not firing.
Finally it needs to be mentioned that losing muscle mass or getting weaker when training on an empty stomach is not a con. People respond differently to different training styles and while this might not necessarily be an optimal approach for training to build muscle it certainly cannot be shown to have any negative impact on your physique either.
Cardio on an Empty Stomach
Cardio on an empty stomach is often the preferred method when it comes to ‘working out’ on an empty stomach. With depleted glycogen stores and no readily available energy sources through digested food, the idea of fasted cardio is to tap into fat stores for energy.
For those that are bodybuilding this is a good tactic to utilize during a fat loss phase however is not ideal during a bulk when the focus is on a caloric surplus and building muscle. There is also no resounding evidence to say that fasted cardio is superior to any other form of cardio for fat loss.
As with your training session then this decision will likely come down to lifestyle and personal preference. When looking at working out on an empty stomach for bodybuilding the results are marginal in terms of the overall impact on your physique.
Therefore choosing this style of training should come down to personal preference. If you are alert first thing in the morning and see no decrease in your performance in the gym then this approach is best if it keeps you training consistently.
If however you struggle with morning routines then don’t try to force them as your performance and ultimately progress will suffer as a result.
Also check out:
How to do cardio without losing muscle mass
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