By definition, metabolic conditioning refers to conditioning exercises that increase the storage and delivery of energy for physical activity. All training requires use of the muscles to produce energy; what distinguishes metabolic conditioning (or “METCON”) is how energy is created, how it is used and how rapidly it is expended.
The first thing that comes to mind for most people when training to improve endurance is conditioning the cardiovascular system to improve transport of blood to the working muscles. Concurrently, metabolic conditioning is conditioning the muscles to better use the fuel delivered to them by improving the efficiency of the different metabolic pathways. While it was once believed that only aerobic conditioning served to increase cardiovascular health, studies have now shown that anaerobic conditioning may also condition the heart to a same level as aerobic training alone.
Generally, all out efforts of two minutes or less are anaerobic while efforts lasting more than several minutes are aerobic. Anaerobic efforts are high powered. Metabolic conditioning with varying and mixed exercise modalities avoids specificity of adaptation allowing for additional cardiovascular/respiratory adaptations and increased functional strength. With these two things, also comes a leaner and aesthetically pleasing physique.
The unique hormonal response of this type of exercise is what drives the results, NOT calories burned. Anyone who tells you different just does not understand his or her endocrinology. It is true, calories must be burned, but it is hormones that determine what type of calorie you will burn... stored glycogen (sugar) or stored fat. In addition, intense exercise such as this can always push the body into a state of muscle break down (catabolism). Research on cyclists has shown that intense exercise sessions lasting over 40 minutes push the stress/growth equation more towards catabolism than towards anabolism (gain of muscle tissue). The ratio between catabolism and anabolism needs to be balanced so that fat can be burned while muscle is gained or at least maintained. Besides, if you are seriously metabolic conditioning you will not be able to last beyond 20-30 minutes. If you do, then you are pacing yourself and likely just doing an aerobic zone workout. If that is what you want, just go do any standard boot camp workout. Pacing in this workout is the last thing you want to do. Push hard, and then rest until you can push hard again. That is the way it is done, plain and simple. When the workout is kept short, generating enough intensity is not a problem, but as the duration increases pacing usually ensues. That being said, 10 to 30 minutes is usually all it takes. And a 30 minute conditioning workout is a unicorn. The only time you will see a 30 minute MetCon is a hefty chipper.
True metabolic conditioning is individualized. Everyone’s sweet spot is a little different. This is why “one-size-fits-all” circuits with defined rest periods are not nearly as effective. Circuits done in sets with defined rest periods are trying to fit the old “do-a-set- and-rest” model to metabolic conditioning and it only serves to decrease the effect. In order to get the proper response, people should rest just long enough to be able to push hard a second time. This is why you never see me prescribe rest. Rest is completely relative to the individual and how hard they are training. CPTs and coaches need to be taught to think of the phrasing “push till you cant, rest until you can”. The harder one pushes the more they will have to rest, and the more they rest, the harder they will push and the greater the metabolic stimulus they will enjoy. This is not based on some predefined rest segment but on ones own metabolic ability.
The purouse of this book: teach you how to program for yourself as well as provide you with a plethora of examples, suggestions, and ideas.
MET[abolic]CON[ditioning]: the ultimate way to get lean, get powerful, and get fast. Now you can finally do away with long, boring, pointless steady state cardio.