There is the tendency for new CrossFit athletes and trainers to avoid heavy days entirely or execute them incorrectly. However, CrossFit is a strength and conditioning program.
While people sometimes characterize CrossFit by its programming of mixed-modal workouts for time (“met-cons”), this is a limited view. Days devoted to strength training are essential to CrossFit and are integral to CrossFit’s prescription of constantly varied workouts.
Heavy days are necessary to build top-end strength and power. Power output decreases with time, meaning that an athlete’s work capacity in very short time domains sets the theoretical limit for his or her entire curve . It is possible to have high levels of short-duration power and little power elsewhere (e.g., a powerlifter), but it is impossible to have low levels of short-duration power and higher levels of longer-duration power. Therefore, heavy days are essential to a general physical preparedness program and should be used at least once a week or once every two cycles .
Heavy days are not the only time athletes drive strength adaptations. Even within a metabolic-conditioning workout, depending on the task and the capacity of the athlete, any number of exercises may build strength. Push-ups for novices build pressing strength similar to a bench press, and attempting a 95-lb. thruster for a new CrossFit athlete builds squatting strength. As an athlete’s strength increases, push-ups and 95-lb. thrusters tend to favor other adaptations such as stamina, and greater loads are necessary to further increase top-end power.
Heavy days can be completed with most any weightlifting or gymnastics movement, such as weighted dips and pull-ups and lifting odd objects (e.g., sandbags, axles). More often than not, however, a barbell is best because it is impossible to match the barbell’s ease and range of loading with other equipment. Heavy days may also include all variations of standard barbell movements (e.g., hang, power, from a deficit, pulling from pins/bumpers).
Cardio is great for burning calories, but to truly change the way the body looks weights should be in the game plan. Intensity is what gets results. This can look many different ways from a set of 50 to 5 maybe even 1 if the load is heavy enough. The goal on heavy days is to get strong. The stronger you are at a lift the longer it will take to get tired in your met-con WOD when doing said lift.
Bring the same energy to class on heavy days and be ready to cheer on people for hitting a PR. This is the way to make heavy days just as much fun as met-con days. I get it as a CrossFitter we look for that feeling of death laying in a pool of our own sweat knowing that not everybody is capable of pushing their self to that breaking point, and then going a little further. Heavy days with make it where we can go longer is all!!
Remember this always... The stronger you are the harder you are to kill!!!