At lower levels of intensity, we burn a higher percentage of calories from fat compared to those from carbohydrates. That much is true. That being true, why then do we not wake up skinny since we're hardly moving in our sleep? The reason for this is revealed by some simple math (All of these calorie numbers are estimates since everyone is different. Individual's statistics (height, weight, etc.) need to be taken into account, but they will serve to illustrate the point.). 

Let's say we walk on a treadmill for 30 minutes at a respiratory quotient of 0.8 (RQ=The volume of CO2 output divided by O2 intake over a period of time. More than you need to know, but there it is so you don't have to look it up. I know you really wanted to. :-) ) and it burns us 110 calories. At this RQ rate we should be burning about 65% of our calories from fat. So, we burned off roughly 71.5 calories in that half hour. Yay for us, there goes the four whole chocolate covered pretzels we ate earlier (doesn't seem worth it, does it?).

Now, let's keep the timing the same, but bump the intensity up to a moderate run so we get the RQ closer to 0.9 (the RQ scale runs from 0.7-1.0 for reference). With this increase effort, we're only burning about 32% of our calories from fat. So, this sounds like a bad place to be doesn't it? Why would we want to put forth more effort for a smaller percentage of payout? Well, we're not actually because at this higher intensity we're burning more calories overall. See where this is going? At this higher intensity, we might be burning about 260 calories total which means we're up to around 83.2 calories from fat even though we are at a lower percentage of fat burned. The difference between the two amounts of fat calories here and in the paragraph above may not seem like a lot, but remember that exercise is cumulative and every little bit counts over time. Plus there's a bigger difference in the calorie count overall. This isn't to say you should hit it hard every time; we still need to balance out with lower intensity training here and there. It is to say, "Don't be afraid to kick it up a bit."

So, that's it: With just a few paragraphs and a bit of math, the "Fat Burning Zone" myth is busted. It's simply a tool used by marketers of exercise equipment, fitness trackers, etc. to entice you into buying one particular model over another. But now that you know their game, you're one step ahead of them. So, if the sales person tells you the device has a "Fat Burning Zone", just give them a vacuous stare, smile, and move on with your next question. The math doesn't lie. 

I hope this has shed some light on at least one crazy aspect of the world of fitness and that you'll use this information the next time you exercise (Which should be right now. Go! Get another 15 minutes in! Seriously, I'm not kidding. Go!).

I set out today to create a combination move that targets most of the main muscles and the core. I spent my whole exercise block stringing together moves and came up with something that...well...it's not nice. I'm calling it The Beast of Burden. This is what the set up looks like. Click here for the video.

For the first time in a long time, I almost hit the wall. Today, as I was well into a chest and back routine, I started feeling less energetic and slightly faint. Instead of pumping out alternating sets of pushing and pulling exercises, I found myself requiring mid-set rests in order to finish. Frustration set in. Why, in years, was this happening now? What the heck was I doing wrong? The answer was 'nothing'; I wasn't doing anything wrong as the 'wrong' had already been done.

It wasn't until I backtracked that I found the culprit. The problem was that I hadn't eaten enough today. Breakfast was the usual, so that got me through the early training sessions, but lunch was seriously lacking. I can only blame myself as my mind was set on using the precious couple hours I had free today to study for my next certification. In the whirlwind of excitement, I downed some veggies and chicken and a touch of pasta before breaking out the study material.

After finishing today's study, I began my routine. What was supposed to be a solid 60 minutes ended up clocking in around 40. While I had the right amount of protein for my weight and enough veggies to kill a small horse, my complex carb intake was definitely lacking. As such, my glucose levels were low and I had started to rip into my glycogen stores. 

Lesson of the day (mostly to remind myself): EAT! If you're burning fuel, you first need fuel to burn, dummy.