Cardio – you can love it, or you can hate it, but it should make up at least a small part of any good fitness plan. Many people turn to cardio when they want to melt fat, and when combined with a good diet and some weight training, it does the job. However, when, for how long, and at what intensity you do your cardio workouts could have an effect on your long-term goals.
There are several strategies you can apply to your cardio routine to help you meet your specific goals, and some of the most popular terms you may be hearing are “HIIT” and “fasted cardio”. In this article, we’ll dive into what fasted cardio is, the benefits and negatives of this kind of training, and how you can use it to meet your goals.
What is Fasted Cardio?
Simply stated, fasted cardio is when you perform a cardio workout in a fasted state, as opposed to a fed state. This usually means working out first thing in the morning, before having breakfast (or breaking your fast…get it?).
Fasted cardio was popularized in the very late 1990s by fitness author Bill Phillips in his book Body for Life. The main concept is based on the fact that when the body is in a fasted state, like when asleep, it shifts its energy usage from stored glycogen to fat. By training in a fasted state, the idea is that your body will still use fat as its main source of energy, therefore burning more fat during your session than if the body was using its preferred source from carbs.
On the surface, this cardio strategy sounds like a no brainer. However, studies are conflicted as to the real results of fasted training. In the next section, we’ll discuss some of the benefits and drawbacks of fasted cardio
Benefit – Higher Fat Burn During Exercise
One of the most valuable benefits associated with fasted cardio is burning more fat than if you had a small meal first, and there are some studies that support this. One UK study found that participants who trained in a fasted state burned roughly 20% more fat than those who ate before training.
However, it is important to note that while more fat may be broken down to be used for energy during fasted cardio, not all of it is needed or used. Unused fatty acids get re-stored as fat, so you may not be shedding as much fat you think.
Benefit – Targets Stubborn Fat
While the science still may be out on how much fat fasted cardio actually burns, anecdotally, many people have had success using it to target fat in stubborn areas, including around the abs and lower back for men, and around the thighs and hips in women. This is why fasted cardio is a favorite for competition bodybuilders, particularly when they’re trying to cut or prepare for a show. This kind of stubborn fat blasting is usually noted in those in the low range of body fat percentage, meaning roughly under 10% in men, and in the very low teens for women. If you find yourself in this range, fasted cardio may be exactly what you need to shed those last few unwanted fat pockets.
Negative – May Encourage Muscle Loss
The biggest argument against fasted cardio is the potential for it to waste away your hard-earned muscle, as your body breaks down muscle to get at the precious energy stored inside. This is a concern during any cutting program, which is why nutrition is so important to the muscle building process.
Negative – Can’t Push as Hard
Another negative against fasted cardio is not being able to push as hard in your workouts. Many people find that they don’t have the energy to push as hard as they usually do. While the answer to this is to work out at a more moderate intensity (which also helps to save your muscles), many may find that this takes the enjoyment out of their workouts. If you like to work hard and push your limits during your workouts, you may want to skip out on fasted cardio.
Fasted Cardio Workouts
As mentioned above, fasted cardio runs the risk of breaking down muscle, and you may feel more depleted and dazed when you finish than with a regular workout. To avoid both these effects, it’s a good idea to keep your fasted cardio workouts to roughly 30 minutes, and at a moderate intensity. While you may burn more calories during a high intensity workout, the idea here is that you’re breaking down and burning more fat. If you have the time, you can burn up those calories later in the day doing a hard, fed weight training workout.
Another reason to keep training levels moderate while doing fasted cardio is to keep cortisol levels in check. Sustained high levels of cortisol will also lead to muscle break down, and can have an effect on your testosterone levels, an important hormone for the muscle building process. To avoid cortisol, avoid constant stress (both physical and mental). To help support your natural testosterone production, try pairing a good testo booster, like HF Labs Delta Prime, with a regular weight training program that focuses on big, compound movements.
What to Eat After Fasted Cardio
One of the most important things about any training program is nutrition. Muscles aren’t built and fat is not melted in the gym alone, so it’s crucial to be aware of the kind of nutrients you’re giving your body.
After a bout of fasted cardio, it’s recommended to have a meal made up of both protein and carbs to help further stave off any muscle breakdown. Good options include:
- Scrambled eggs and toast
- Greek yogurt with fruit/berries
- Cottage cheese with fruit or tomatoes (sweet or savory!)
- Tuna sandwich on multigrain bread
Make sure to give your body the energy it needs by having this meal as soon as possible after the workout. While it’s debatable that you may experience more fat burning if you wait, you also risk losing more muscle mass.