The great thing about the human body is that everyone is different and responds differently to many things!  For example, some people lactose intolerant and cannot have milk but that is not to say that milk is bad for everyone. 

As a rule of thumb, having an external source of energy (some sort of food) prior to working out is without a doubt safe and guaranteed way to provide energy for a strenuous workout.  When it comes to working out fasted, however, the amount of time held fasted plays an important role. 

When it comes to working out fasted we will break it down into two categories: post-rest fasted and extended-fasted.  Post-rest fasted would be, as the name explains, just having woken up from a rested state.  An extended fast would then be any extended period of fast after awakening.

In regards to working out in a post-rest fasted state vs an extended-fasted state, if you decide working out fasted is what you want to do, we recommend a post-rest fasted state over an extended-fasted state. 

Working out in a post-rest fasted state you have a much shorter time between your last meal compared to an extended-fast.  This will allow you to utilize any energy storages you may have left from your previous meal much more efficiently.  Also, the longer you are fasted while awake, the more calories you are burning causing you to be much more hungry and lower overall physical and mental energy levels.

Now, for the big question, Is it bad to workout fasted and can you build muscle doing so? The answer is NO to “is it bad” and YES to “can you build muscle doing so”! 

Keep in mind, however, what is good for one person may be bad for another so some experimenting must be done.  We advise doing so under the supervision of your doctor and having a workout partner or personal trainer there to make sure you are not putting yourself at risk.

When it comes to building muscle, at the end of the day it comes down to being able to properly reach muscular failure to induce muscle growth AND being in a caloric SURPLUS to accommodate it.  This means that if you are not working out hard enough or eating enough calories to build muscle, it does not matter if you workout in a fasted or fed state, you will not not be able to do so!

You may be asking yourself, why on Earth would anyone want to workout fasted?  And this is a valid question!  

One reason being that fasting has been proven to sharpen your cognitive ability and stay focused for longer periods of time.  Working out and building muscle requires strict concentration and focus in order to ensure the proper requirements above are met and the increased cognitive effects of fasted can compliment this nicely.

Another reason is that it is out of convenience!  Many people who work a normal “9-5” may not have the physical or mental energy and motivation at the end of the day to workout, or they have a family they want to spend time with and doing so after work allows them the most free time.

When working out in a fed state it is recommended to have sufficient time before working out to digest.  If you are someone who needs to workout in the morning, for one reason or another, working out fed requires waking up earlier in order to have the proper time to digest.  

Also, trust us on this, working out when you feel full is not something you want to experience (think eating before riding a roller coaster…) let alone the amount of extra sleep time you will either be required to either sacrifice (topic for a future post) or forced to adjust your sleep schedule to fall asleep earlier in the day. 

One thing to note, working out fasted has a potential negative side effect of lowering your blood sugar.  There is probably a time in your life where you have felt the effects of this (lightheadedness, dizzy, fatigued) and it is something very serious to take note.

Lifting heavy weights requires concentration and strength and being in that state does not mix well!  You will be potentially putting yourself in a dangerous situation by combining the two. So again, WE ADVISE CONSULTING WITH YOUR PHYSICIAN AND SUPERVISION FROM A FRIEND OR PERSONAL TRAINER when you first start out for your safety and wellbeing!