There’s so many mixed opinions in the fitness and nutrition space regarding fasted and fed workouts and what “diet” is best for you so let me add one more to the mix.

According to Google, “intermittent fasting is any various meal timing schedules that cycle between voluntary fasting and non-fasting over a given period”.

When combined with a workout, this is what we call a fasted workout. Precision Nutrition defines fasting as, “a metabolic state that the body enters after 8-12 hours without food”. So technically, any time after 8 hours without food is when the body turns into a fasted state.

Fed or non fasted workouts would be exactly the opposite, eating before a workout to break that 8 or more hour fast period.

Why do people fast?

People will do intermittent fasting so that the window they are eating throughout the day is restricted. The theory is that the less time you have to eat throughout the day, the less you will eat overall. Eating in a calorie deficit = fat loss.

The idea behind working out in a “fasted” state is that your body (since it has no food for fuel), will use your fat stores as energy to fuel your workout. So in theory, people believe they are burning more fat directly by doing fasted workouts.

Pros and cons:

Outside of potential fat loss, I think intermittent fasting has many benefits that are overlooked such as:

• Improved brain and heart health
• Increased focus
• Age slowing benefits
• Improved insulin resistance which can reduce risk of diabetes
• Reduced cholesterol and inflammation levels in the body

As with everything, intermittent fasting also has its cons:

• Can back fire and lead to late night cravings, binging or overall fat gain
• Can cause disordered eating or even an eating order due to the restricted time windows
• Can leave you tired, dizzy or nauseous if you don’t eat for long periods of time
• Can reduce reproductive hormone levels in females
• Can make you feel weak during your workouts

What are the different types of fasting?

There are quite a few different ways that you can do IF (intermittent fasting) but we are going to go over the top 3 here:

1. 16/8 method – this requires a 16 hour fast period followed by an 8 hour eating window
2. 20/4 method – this requires a 20 hour fast period followed by a 4 hour eating window
3. 5:2 method – this requires you eating your maintenance level for 5 days a week and then restricting to only 500-600 calories total each day for 2 days a week

These are just the most recognized fasting methods but there are various others including methods where you don’t eat for a whole day, or even a few days.

Doesn’t fasting slow down your metabolism?

Well, it depends. If you are losing weight overall, yes your metabolism will slow down.

There is a lot of back and forth in the research to whether or not normal calorie restriction or fasting is better for your metabolism.

Each have benefits and I’ve personally concluded through research that they both have about the same effect on your metabolism all in all.

Your metabolism and the thermogenic effect of food increases not by how often or when you’re eating, but rather how MUCH you’re eating overall. So based on these facts, it doesn’t really matter when or how much you’re eating in one sitting. It is about how much food you’re eating throughout the day.

Whether or not you want to eat a bunch of smaller meals, or a few larger meals is really up to you and what you feel works best for your body. Some people will operate better on one vs. the other.

Is it right for you?

In general, fasted workouts are considered safe for most people. I think it is a good option for those who may need a more structured routine and for those who feel good when not eating before workouts.

It is also important to note that intermittent fasting does not directly have to be combined with a workout routine. You can do intermittent fasting (not eating until whatever time) and then have a fed workout later in the day or not even workout at all.

Most people only relate intermittent fasting to the fat burning benefits so that’s why we are talking about them so closely together in this post.

I think that fasted workouts or fasting in general is NOT a good option for those who are regularly under a lot of stress.

Fasting can be so restrictive that it puts additional stress on the body and can actually do more harm than good.

My take on it

Overall, I’m not a huge fan of fasted ANYTHING. Ya girl likes to eat.

I think that most people fast without realizing it between their last meal each night and breakfast in the morning. This period of time can be anywhere from 8-12 hours if you think about it.

That is perfectly good to reap the benefits of intermittent fasting that we talked about above (non-fat burning related).

Whether you want to do intermittent fasting more so on purpose is really personal preference.

Some people feel better during their workouts when they eat before, some don’t.

I think it’s important to note that doing intermittent fasting alone won’t just magically melt fat off your body.

If it has any additional fat burning effects as the research claims it potentially could, they can easily be reversed throughout the rest of your day.

The point of intermittent fasting alone is to restrict or reduce calories overall throughout the day.

Even if you intermittent fast and don’t eat until 12pm and even work out in a fasted state…

If you don’t eat in a calorie deficit overall you will experience NO fat loss.

Meaning if your TDEE is 2500, even if you intermittent fast but are eating 2500 or more calories a day, it is doing absolutely NOTHING for your fat loss goals.

My best advice would be to try it both normal calorie restriction (just eating in a 500 calorie deficit each day) and intermittent fasting for a week or two each. See which feels better for you. Remember, even if it has some fat loss benefits in the short term, it could be potentially harmful to you in the long term.

If you absolutely hate it, don’t do it. It’s not worth being miserable about. You can lose fat perfectly fine while doing fed workouts and just simply eating in a calorie deficit each day.

Until next time,

Coach Emily