I have been wanting to do a post on this for awhile now because I have been testing it (rather intensively) on myself for the last 4 months or so. I have gone into ALL of my workouts fasted (some weight-intensive, some cardio-intensive).
Some things I was worried about when beginning this, based on things I had learned in school or through my own experience with working out:
- Will my body opt for fat (ideal) or jump to protein (muscle degradation -- not ideal) as an energy source if I am fasted? In other words, will I lose too much muscle? I had actually seen an article that claimed all the fasted working out people were doing, was bad for the system, despite the number of people doing them.
- Will my workouts just be BRUTAL? With no FAST energy source, is it just going to suck to be in the gym?
- Will my muscles somehow fail without sufficient nutrients in the body/blood?
- Will they seize up/cramp because of a lack of electrolytes?
What ended up happening:
My first workout was pretty rough. I FELT low energy. My quads actually cramped up. I finished my workout (avoiding quad work), but it was like getting hit by a bus...sooo I wasn't exactly a proponent of fasted workouts at first.
What came after that though, was well worth it! I started having extraordinary workouts! It was never like the first one again. In fact, I felt like I had more energy than normal heading into each workout. The best part? I started shredding up significantly, without doing all that much cardio. It became a win-win for me. Additionally, the increase in growth hormone production (from the fasting) actually helped me continue gaining muscle. More on that here.
I now look forward to and prefer my workouts to be fasted. If you are interested in trying this, what I recommend is this: Ensure minimal muscle issues by eating well in the days leading up to that first workout. Then, ease into the workout as it may be a little rougher than normal. After you get used to it though, I am sure you will prefer it too.
MAKE SURE YOU EAT AFTERWARDS to refuel your body! Remaining fasted and hypo-caloric can only be beneficial for so long before it starts eating up muscle. Additionally, something that I have found helpful is supplementing with a Branched Chain Amino Acid (BCAA) before and/or after the workout. This will help protect your muscle on your quest to burn off enveloping fat and gaining that lean build.