I really don’t care what your FitBit says, or your Apple Watch…throw away the “fat burning zone” schtick.  Here’s a hard dose of reality, you’re in the fat burning zone when you’re watching Monday Night Football, drinking a beer, watching your awesome 85” screen.  At that time, the majority of the energy you’re metabolizing is coming from fat…in other words, low intensity activity utilizes a higher percentage of energy from fat. 

(Forewarning about language)

This is the sh-t that led to our crap industry incorporating the hamster wheel of treadmills and bikes that formed the fitness industry for the 20th century.  We loaded gyms up with “cardio” equipment and convinced the general public this was the way to go for fat loss.  This simpleton approach to physiology overlooked the physiological fact that utilizing fat for energy isn’t all that impressive when you’re not utilizing much energy.  To make matters worse, this type of exercise has shown to be extremely catabolic…meaning you’ll also utilize muscle tissue for fuel. 

You’re better off going (almost) full-CrossFit, or the other end of the spectrum and just take your dog for a walk.  Option #1. will definitely be better to first responders preparation...something close to my heart (obviously).  Let’s take a look at both:

HIIT, MetCon, or whatever you want to call it has been shown not only to save muscle, but also build it under the right conditions.  Add the awesome effects of post-exercise oxygen consumption (EPOC) to the benefits of going “hard” and you have a real winner.  Just to clarify, EPOC is the “after-burn effect” of hard exercise, forcing your body to utilize additional O2 during recovery to account for the oxygen debt you built up during your workout.  This process also continues the fat burning process with an elevated metabolism for an extended time frame after your workout.

Not to mention, activities a first responder will have to prepare for more closely resemble the short-duration, all out sprint than 40 minutes on a step mill. 

For this, try sprints, EMOM with big bang exercises, or even Tabatas on whatever.

Now, this is where CrossFit get’s “it” right sometimes, and extremely wrong others…really depends on the coaches.  You cannot go all out all of the time…you will break.  The low-down, easy activity approach is a great supplement here.  Take your dog for a walk, take a nice bike ride with the fam, etc.  There are so many benefits to this 2-3x/week activity…so just put those in there.