At our most recent coaches meeting last week I stood in front of our coaches and talked about intensity. I used an anecdote from the past few weeks; one of our members asked me about cardio (read the article I wrote on this already) and before I could answer they said their heart rate would get to 170bpm. And the question was – “Isn’t that intense, isn’t that better than just running a 5K?” The answer is a little nuanced. A high heart rate can mean there was high intensity, but it is not a guarantee.
Intensity is equal to power (power is defined as force times distance over time); intensity is power created and the ability to create power. A high heart rate can be sustained and even created without almost any power creation. As a result it is difficult to say that an activity which creates a high heart rate is intrinsically intense. It is important to note that intensity is relative to the individual and is determined by the physiological and psychological tolerance of that individual. Like everything in CrossFit we look to vary the intensity for an athlete by DEGREE not by KIND. This all wraps back around to scaling, a barbell power snatch at 135lbs for Coach Isaac for 30 reps may facilitate a relatively similar response from a newer member with a 30lbs dumbbell snatch. Additionally, Coach Isaac will probably perform 23 of the 30 reps almost flawlessly which will affect his power output as well as the physiological response to the workout. Most people probably can’t do that and so the barbell snatch gets scaled by load, rep, or even movement.
On Friday we did an interval workout with calorie bike as a measurable element to the workout. The assault bike offers a very interesting perspective on power output because it is a very low skill movement that offers immediate feedback to the athlete. Once we see the RPM dip below 60 we know that not enough power is being generated to keep the calories ticking. The easy answer is to reduce the calorie target to allow the athlete to maintain a higher power output and to maintain intensity – scaling by degree not by kind. There are some unique circumstances where the bike is simply too hard for smaller people to generate enough power to make the workout effective. In that case we would use a different modality. You may have noticed some very strong athletes getting completely wrecked by that workout. Were they being dramatic? Possibly. More likely they are able to move the bike faster than others in turn actually making the workout harder. The answer to Jeff’s question, “When does CrossFit get easy?” might just as easily be “When you lose the ability to create power”.
CrossFit and especially our program at Verdant is designed to increase your fitness, to enable you to move large loads quickly and over a large distance. We are trying NOT to specialize, as too much capacity in one area quickly compromises another. Take the example of a powerlifter, Coach Isaac, and a marathon runner. The powerlifter and marathoner runner will win their respective events but will finish dead last in all other events. Coach Isaac will easily get second in everything, by a significant margin. I would argue that Isaac is a much better example of fitness than an elite marathon runner who probably can’t do a bodyweight back squat and a powerlifter who probably can’t run a mile without having a heart attack. True fitness is a compromise, but it allows us to be remarkably good at a host of events.