Unsurprisingly, there are several questions that seem to get asked again and again. Since there is apparently a lot of confusion around some specific topics, I have decided to address them in blog posts.
The question I will answer in this particular post is about the effectiveness of doing your cardio workout first thing in the morning in a fasted state.
I see where the confusion comes from, because so many experts disagree about the merits and potential drawbacks of this technique. Some say it increases fat burning by up to 300%, while others say that it will result in muscle loss. Now that’s a significant difference in opinion! What’s the truth?
Well, I have experimented with fasted morning cardio rather extensively over the years, and I have the data to end the confusion once and for all.
The truth is that fasted morning cardio can be an effective fat burning technique in some cases, but in others, it can be catabolic. So the short version of the story is that both sides of this argument have a valid point.
The long version goes something like this: whether you have positive or negative results from morning cardio depends on several factors. These factors include: nutritional status, amount of lean muscle mass (LMM), intensity, duration and type of exercise.
Now, I’ll break each factor down for you.
1) Nutritional status- Fasted morning cardio (FMC) works great on the morning of a low carb day to help accelerate the burning (utilization) of stored carbohydrates. By doing this, you will tap into your fat stores much earlier in the day, therefore burning more fat throughout the day.
So if you are carb cycling, there are some upsides to starting a low-carb day with a fasted morning cardio session.
2) Intensity- Although high intensity cardio is a better and more efficient fat burner than low intensity cardio, it could lead to overtraining and muscle loss while done in a fasted state. This is particularly true for advanced trainees. So if you consider yourself to be advanced, and you do your cardio in the morning on an empty stomach, you MUST lower the intensity. The optimal intensity is in between 65-70% of your max heart rate.
3) Duration- Because the intensity will be on the lower side, you need a relatively high duration. I recommend 30-40 minutes per workout. Anything less than 20 minutes will not burn an appreciable amount of fat.
4) Exercise Selection- Additionally, the activity of choice should not have a significant eccentric component. In layman’s terms, this means you should avoid activities that deliver a high external force through your body.
Running, jumping, and jogging all have a high external force. These activities can lead to muscle loss if done excessively while in a fasted state.
Instead, you should emphasize activities that don’t have a high external force. Walking, biking, low intensity bodyweight circuits or various cardio machines fit the bill here.
5) Amount of Lean Muscle Mass (LMM)- The more lean muscle you have, the more careful you have to be about your morning cardio. Point 2, mentioned above, is particularly important for those trainees with a high LMM. They really have to keep an eye on the intensity of their morning cardio or they will find themselves unwittingly burning off some of that hard-earned muscle.
Now let’s discuss what type of trainee should consider employing this cardio technique. As a general rule, I am a big proponent of high intensity athletic based cardio for dramatic body transformation.
I have found that this technique delivers more fat loss bang for the buck, so to speak. This type of cardio can be done at anytime during the day. I would, however, NOT recommend doing it in a fasted state. In other words, if you want to train in the early morning, at least have breakfast first.
That’s because performing intense work in a fasted state could hinder your workout, and thus, your fat loss results. Thus, put in simple terms, for the majority of trainees out there, I do NOT recommend fasted morning cardio.
That being said, there is one important exception to this rule: advanced trainees in an accelerated fat loss phase. Specifically, I am referring to those trainees out there who have developed a significant amount of lean muscle and happen to be on a restrictive diet for rapid fat loss.
For those people, high intensity athletic based cardio can actually burn muscle. It can also cause overtraining, which can take away from the effectiveness of their other workouts. For instance, if a developed trainee is doing hill sprints 4 times a week, their leg workout will most definitely suffer.
For these advanced trainees, I recommend a lower intensity cardio workout. This will encourage fat loss but maintain your muscle mass as well. Since the intensity is low, we have to find creative ways to maximize its benefits. First of all, as stated above, you should perform this low intensity cardio for 30-40 minutes. In addition, you should perform this cardio in the morning and in a fasted state. This will maximize the benefits of your workout.
So, in conclusion, I do not recommend fasted morning cardio UNLESS you are an advanced trainee. In this particular case, I would recommend fasted morning cardio, but make sure that the intensity is low enough that you do not burn muscle, and that the duration is long enough that maximize the fat burning effects of this type of exercise.
I hope that helps clear up any confusion that might be out there about this very controversial topic. Adjust your cardio workouts to the guidelines listed above, and I guarantee you’ll be glad you did!
Feel free to leave any comments or questions in the comment section below. I’ll see you there!
Dedicated to your success,