Only thing with "Fasted" Cardio is it really doesn't hold any benefit over fed cardio. At the end of the day doing your cardio is what matters most. Being in a fasted state truly dosse not provide any positive results or scientific feedback.
http://forum.simplyshredded.com/topic/2209/layne-smashes-the-myth-of-fasted-cardio/
https://jissn.biomedcentral.com/articles/10.1186/s12970-014-0054-7
Conclusion
In conclusion, our findings indicate that body composition changes associated with aerobic exercise in conjunction with a hypocaloric diet are similar regardless whether or not an individual is fasted prior to training. Hence, those seeking to lose body fat conceivably can choose to train either before or after eating based on preference. It should be noted that given the small sample size and short study duration, we cannot rule out the possibility that either condition might confer a small benefit over the other with respect to fat loss. Further study is warranted in a longer term trial with a greater number of participants.
No difference....
http://www.simplyshredded.com/myths-under-the-microscope-fasted-low-intense-cardio.html
Fed subjects consistently experience a greater thermic effect postexercise in both intensity ranges.
https://www.t-nation.com/training/fasted-cardio-eats-muscle
https://breakingmuscle.com/learn/debunking-the-myth-of-fasted-cardio
Good article from Brad Schoenfeld
Horowitz and colleagues [2] found that when trained subjects exercised at 50 percent of their max heart rate, an intensity that equates to a slow walk, there was no difference in the amount of fat burned--regardless of whether the subjects had eaten.
These results held true for the first 90 minutes of exercise; only after this period did fasted cardio begin producing a favorable shift in the amount of fat burned.
So unless you're willing and able to slave away on the treadmill for a couple of hours or more, fasted cardio provides no additional fat-burning benefits, irrespective of training intensity.
Fasted cardio makes even less sense when you take into account the impact of excess post-exercise oxygen consumption. EPOC, commonly referred to as the "afterburn," represents the number of calories expended after training. Guess what? Eating before exercise promotes substantial increases in EPOC
And guess where the vast majority of calories expended in the post-exercise period come from? You got it, fat!
Take Home Message
"More epoc equals more fat burned. This favors eating prior to performing cardio."
There's also the intensity factor to consider. Research indicates that high-intensity interval training is more effective than steady-state cardio for fat loss (Bill Phillips actually recommended HIIT as the preferred type of cardio in his book).
Ever try to engage in HIIT session on an empty stomach? Bet you hit the wall pretty quick. In order to perform at a high level, your body needs a ready source of glycogen; deplete those stores and say goodbye to elevated training intensity.
The net result is that fewer calories are burned both during and after exercise, thereby diminishing total fat loss.
On top of everything, fasted cardio can have a catabolic effect on muscle. Studies show that training in a glycogen-depleted state substantially increases the amount of tissue proteins burned for energy during exercise (4).
Protein losses can exceed 10 percent of the total calories burned over the course of a one-hour cardio session -- more than double that of training in the fed state (5).
Any way you slice it, sacrificing hard-earned muscle in a futile attempt to burn a few extra calories from fat doesn't make a lick lot of sense--especially if you're a bodybuilder!
To Cardio Or Not To Cardio Before Breakfast
Summing up, the strategy to perform cardio on an empty stomach is misguided, particularly for physique athletes.
At best, the effects on body composition won't be any better than if you trained in a fed state; at worst, you'll lose muscle and reduce total fat loss. So if you should eat…what should you eat prior to cardio?
The answer depends on several factors, including the duration and intensity of training, the timing of previous meals before the cardio session, and individual genetics.
A good rule of thumb is to consume approximately 1/4 gram of carbohydrate and 1/8 gram of protein per pound of your ideal bodyweight (which may differ from your actual weight).
For example, if your ideal bodyweight is 200 pounds, then your pre-workout meal should consist of approximately 50 grams of carbs and 25 grams of protein. A shake made of natural fruit juice and whey protein is a good option, particularly if cardio is done early in the morning before breakfast.
Of course, individual response to macronutrient intake will vary, so use this recommendation as a starting point, and adjust accordingly.
