Can Fasted Cardio Make Your Workouts More Effective?
When given the choice of an early breakfast before your morning workout or a few extra minutes of sleep, most of us will choose to snooze for longer! This could be to your advantage, as working out in a fasted state (ie. after sleeping) can have benefits.
With the recent popularity of intermittent fasting, more people are working out in a fasted state. Some people even say they have more energy for their workout when doing fasted cardio! For others, exercising in a fasted state can leave them feeling unwell or dizzy.
While fasted cardio is popular with celebrities and high-profile fitness trainers — does it really work? We cut through some of the controversy to take a look at what this style of cardio is, and the pros and cons of exercising in a fasted state.
- What is fasted cardio?
- What is a fasted state?
- Do you have to do fasted cardio in the morning?
- Benefits of fasted cardio
- Downsides of fasted cardio
- Best fasted cardio workouts
- Eating after fasted cardio
What is fasted cardio?
Fasted cardio is simply cardio that’s completed when your body is in a fasted state. This is usually 4-6 hours after eating — not when your stomach feels empty! Fasted cardio can help some people to shift stubborn fat by increasing the amount of fat converted to energy to fuel the workout.
What is a fasted state?
You are in a fasted state when your insulin levels are at a low or baseline level.
Insulin is the hormone that’s produced when you eat. It helps to move the energy from the food just eaten into the cells of the body.
When insulin levels are high, the cells have fresh energy ready to use and they won’t be using energy stored in your body as glycogen or adipose tissue.
When insulin levels are low, the cells don’t have readily available energy. This means they must rely on the body’s internal energy stores. Exercising in a fasted state increases the rate of lipolysis and fat oxidation — the breakdown of fat cells to be used as energy and the burning of fat as fuel.
Do I have to do fasted cardio first thing in the morning?
Fasted cardio can be done at any time of day. You can achieve a ‘fasted state’ within 3-6 hours of your last meal, depending on what and how much you’ve eaten.
Benefits of fasted cardio
The purpose of fasted cardio is to burn energy stored in your body, rather than energy from the food you’ve eaten.
If you’re trying to alter your body composition, you need to do more than just change the timing of your meals. The type and amount of food that you fuel your body with is a critical factor in how your body distributes energy and builds muscle.
The benefits of fasted cardio include:
- Increased breakdown of adipose (fat) cells
- Fat released from cells is burned as fuel
- Increased blood flow to the abdomen region
- Facilitates breakdown of adipose tissue stored around the abdomen
- May increase production of hormones that encourage use of energy stored as fat
Why fasted cardio isn’t for everyone
The downside of fasted cardio is that your body can derive energy from any part of your body, not only the adipose tissues cells. This means that fasted cardio can increase the breakdown of muscle tissue.
Fasted workouts might not feel as good as working out when you’ve eaten. Carbohydrates from a recent meal or snack are needed to provide an energy boost for maximum performance.
If you are in a fasted state, you might find you have less energy and focus than normal. Your body should adjust in time as it learns to use stored energy more efficiently.
For some, doing a workout fasted means less energy to perform at their best. If this is the case is for you, you may prefer to eat before working out so you get the most out of each session!
At the end of the day, enjoying your workouts and getting them done in a way that’s sustainable will have more long term benefits for you!
Which workouts are best for fasted cardio?
Fasted cardio workouts will ideally be lower intensity to reduce the potential for breakdown of muscle tissue. This means cycling, walking, jogging or any other form of cardio that keeps your heart rate around 50-80% of your maximum.
If you’re following one of the SWEAT programs, your LISS session is perfect for fasted cardio. Maintain a steady pace throughout the workout, rather than going too hard.
What you eat after fasted cardio is critical
If you’ve completed a fasted workout, what you eat next is important for your recovery. For a strength or resistance workout, protein and carbohydrates are key macronutrients to help rebuild muscle tissue.
For anyone practising intermittent fasting, you should do your workout towards the end of your fast so you can eat a recovery meal shortly afterwards.
If you decide to workout during your fasting period, for example if you're practicing an OMAD diet, be sure to keep the intensity low enough so you don’t feel faint or hungry. Keep the workout short — around 30 minutes is appropriate during a fast.
Ease into fasted cardio to see if it’s for you
If you’re a fitness beginner, or you’ve never done fasted cardio before and you want to try it, start by eating something light before your workout.
You might have a banana or a piece of toast before working out. If you feel good with a small snack, next time try exercising in a fasted state.
For some women, doing fasted cardio is part of practising discipline and finding the motivation to work out, knowing you’ll be rewarded with your next meal! Whether you decide to fast before your workouts or not depends on your personal preference and goals.
When do you workout? Let us know in the comments!
* Results may vary. Strict adherence to the nutrition and exercise guide are required for best results.