All that a fasted workout is, is a workout that takes place before having breakfast. While at first, that may sound like a stretch, it actually makes mornings simple and dynamic.

If you would like to have a look at a more comprehensive guide on intermittent fasting, you can have a look at Intermittent fasting for beginners here. But the truth is that you don’t need to be following an intermittent fasting diet to do fasted workouts.

A fasted workout can be something as simple as going for a jog before breakfast. That seems to be the most convenient time of the day as you are already deep into your fast and you don’t have to worry about preparing breakfast straight away.

How to workout fasted

If you are going to try fasted workouts, a good way to start is by short runs before breakfast. As you have not consumed any calories yet, this is not the time for a HIIT workout or a really long session.

What you are looking to get here is about 30 to 45 minutes worth of steady pace run. If you have some other equipment available that you would prefer over going for a run, like an elliptical or a bike, that’s going to work just as good.

Make sure that you are sufficiently hydrated before working out, and that’s for any part of the day. When you wake up, it is ideal to follow the steps of a functional morning routine that works for you. A simple example that you can follow:

  1. wake up a set time every day without hitting snooze
  2. drink water and hydrate yourself
  3. brew your beverage of choice like tea or coffee
  4. fasted exercise
  5. breakfast (rich in protein and carbs)
  6. shower

If you would like a more in-depth guide on setting up the best morning routine for you, check out Morning Routine and how to enjoy every morning.

What you should know

As with anything that requires us to try something different, to get better health results, we should first make sure that we are not doing more harm than good.

If you have any health concerns or medical conditions, it is absolutely essential to check with your doctor first. Fasting in general can be a great tool for weight loss and detox, but can also be straying in some situations.

Even Though I have tried longer workout sessions while fasted, I would not recommend it. Especially if you are planning on working out again later in the day, long runs or cardio sessions in the morning before breakfast may deplete your energy and slow down your mornings.

Other than that, fasted workouts are not ideal if you are trying to build muscle. Fasting, in general, is about losing weight while making our fat storages more accessible sources of energy. Building muscle can be achieved only by consuming calories on a surplus.

Fasted workout effects

If your question is whether you should try a gym workout while in a fasted state, there are some things you need to consider.

Performance, if you are training for strength, fasted workouts are going to have a serious toll on your lifts. This is no surprise as your muscles require energy derived from carbohydrates to perform optimally.

An interesting view of fasting effects on performance as well as much more is given by Mark Sisson “Fasted Workouts: When They’re More Effective (and How I Incorporate Them)”.

The point of fasting, in general, is to lose weight by using fat as an energy source. The reason for that is the lowered levels of insulin. Insulin release by the pancreas is triggered by the rise in levels of glucose. Which glucose itself rises when we eat food and specifically carbohydrates and sugars.

Simply told, without food glucose levels stay low, lower glucose does not trigger the release of insulin and insulin levels are lowered. When that happens, our fat cells can release the stored sugar to be used as energy.

A process called fat oxidation.


Not optimal for fat loss

Fat oxidation does not equal fat loss. Fat oxidation happens through a process called lipolysis where stored fats are broken down into fatty acids. The use of fatty acids for energy is called fat oxidation.

You do burn “more calories” when working out fasted which can eventually lead to fat loss. But that is definitely not something you can count on. Why? Because unless you are in a caloric deficit, a fasted workout will not assist you in weight loss.

Despite that, the loss in performance due to lack of energy can cause your workouts to be less effective. In comparison for example if you were fed and were able to train at maximum capacity.

Further from that, given that training with depleted glycogen levels has been shown to increase proteolysis, a procedure that means turning to protein as an energy source that leads to a break down of muscle. Rendering it a bad pick if your goal is hypertrophy.


Fasted workouts have been glorified for their fat-burning capabilities. As with anything, working out and being on a calorie deficit does lead to burning fat and losing weight eventually.

Most of the time what we mean by losing weight is that we want to lose fat, no-one wants to lose muscle mass. If this is what you are after, a diet dedicated to a calorie deficit is going to work much better for you. You will be able to maintain consistent progress as long as you are consistent with your diet.

Overall, I would not recommend fasted workouts. Muscle gain and fat loss can be achieved far more effectively with strength training, a balanced diet as well as cardio in between sessions.

If you need guidance on any of the above, have a look here:

References and Useful links:


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