The question of when to do cardio is an age-old debate among people working hard to burn the most fat possible. Some claim that doing cardio in the morning before breakfast is ideal while others say right after a weight-training workout is the perfect time. So, when is the best time to do cardio?
Top researchers Gabriel Wilson, M.S. and Jacob Wilson, Ph.D. believe that doing cardiovascular exercise first thing in the morning on an empty stomach is suboptimal because it can be highly catabolic. That means performing cardio on an empty stomach can eat away at your hard-earned muscle. Considering you would've been fasting for at least eight hours while sleeping and your body is essentially in starvation mode, that makes sense.
They believe you should do cardio right after a weight-training workout because that's when you've burned off all the sugar in your bloodstream. That means your body can tap into stored body fat more easily for the energy you'll need to get through your cardio. Of course, since it's after working out and you'll be dealing with fatigue and the potential of overtraining, you should probably only utilize medium-intensity cardio, not high-intensity interval work during that time.
So, the problem with when to do cardio seems to boil down avoiding muscle loss while also burning fat as efficiently as possible. Does that really mean fasted cardio first thing in the morning is bad since your body will burn excessive muscle as a way to preserve fat for emergency energy use down the road because it senses famine? Maybe not!
The only hurdle to get over with fasted cardio in the morning is avoiding muscle loss, and that makes sense. You don't want to put in all that work to go backward. Even if your goal isn't a muscular physique, losing muscle will negatively affect your performance and ability to burn calories at rest, so it's about much more than just looking good.
Luckily, preventing your body from going into a catabolic state isn't that difficult. The trick is to use a specifically-formulated pre-workout supplement like BCAA Boosted to spike your fat-burning abilities with metabolism-boosting nutrients and natural energizers while also preventing any loss of lean muscle tissue. All that takes is the right amount of branched-chain amino acids and L-glutamine to preserve muscle without having your body go out of a fasted state. And that means you're probably better off doing high-intensity interval training that can dig into those fat stores easily and without spending a ton of time waiting to burn off blood sugar with less productive steady-state cardio.
That way you get the best of both worlds. You can do your cardio on an empty stomach when there's minimal sugar in your bloodstream, allowing you can tap directly into fat, and you can effectively prevent any muscle loss during the process. Of course, that doesn't mean you can't do cardio after weight workouts, but now you can have the peace-of-mind knowing you have two great for when to do cardio.