fasted workout

Fasted workout, what’s the deal?

What’s the deal with fasted workouts?

A fasted workout is when you perform your workout without eating or drinking (apart from water) beforehand. The most common time of day to perform your fasted workout is first thing in the morning before breakfast. However, as long as you haven’t had anything for 4 hours pre-workout, it does count as fasted. Fasted workouts are a slightly controversial topic, with varying viewpoints on the positives and negatives. Let’s take a look.


Calorie burning

The hottest topic of them all, does doing fasted cardio burn more calories?! In 1999, Bill Phillips, bodybuilder and author, introduced the fasted cardio theory. His belief is that working out in a fasted state means the body uses fat stores for energy, because our glycogen stores which our body usually rely on have been depleted overnight.

However, some scientific research is not fully on board with supporting this theory. Dr Smith-Ryan’s research states that eating before a workout, in particular protein, will boost calorie burn rates. You’ll be able to work harder than if you have fasted, and also protein takes more energy to process.
Australian research conducted in 2017 couldn’t determine whether there were any real differences on body mass results from fasting or not fasting pre-workout.


Comfort levels

Many people just can’t exercise after eating. The “wrong” food can make you feel sluggish for some time as you digest it. Some suffer from exercise-induced nausea, which can be relieved by not eating beforehand. Some runners have found that getting their early-morning run in before eating reduces their likelihood of cramps and stitches. However, others have stated they just don’t have the energy and power available for their run that they would like to have.


Energy levels

This is a really individual point, because everyone is different physiologically and everyone has different thought processes. Some people just feel “better” working out pre-food. They feel lighter and more energized. Others will feel like they’re lacking strength and focus.

Fasted workout or fuel up?

Fasted workout or fuel up?

Health and hormones

There are obvious health conditions, such as diabetes, where performing fasted workouts need to be discussed with your GP beforehand. Sugar levels will be affected. Age and sex of the individual may also come into play. Performing fasted cardio can alter normal cortisol secretion levels, which can cause hormonal imbalances. For example, peri-menopausal women who are already going through significant hormonal changes should take this into consideration. The added stress caused to the body may be detrimental to your fitness progress.


The verdict?

Trial and error. You need to work out what works for you and your body, and this can only be achieved by trying it and seeing what the results are. Everyone is different, and no single approach suits all. If you’re already on a fitness journey that works for you, there’s no real need to give it a go. But if you’re in a place where you want to try something different, check it out and see how you get on. As always, be safe, and if you have any existing health concerns, check things over with your GP or medical professional first.


Written by Becky Barrett.

Becky Barrett is an international talent manager and personal fitness coach with over 15 years’ professional experience and a 1st class Honours degree in Business & Law.

Driven by her unique values of compassion and a holistic approach to talent management, Becky has devised an innovative solution to take on the fitness industry with a brand-new personal fitness concept that aims to inspire and boost ‘new normal’ approaches to exercise routines.

Features include: Health & Wellbeing, Natural Health, Arden University, The Telegraph, BBC, Time & Leisure, Bdaily News, The Stage.