For the time I have spent in the fitness and strength and conditioning industry I have really struggled to define fitness. Everyone sort of has an intuitive sense of what it is, but I think that all of the definitions so far have been very abstract and don’t really dial it down to anything concrete and specific.
Crossfit defines fitness as “work capacity across broad time and modal domains.” I respect this definition, but I surely have no idea what it means. I am not even sure what work capacity means anymore because your work capacity is going to be very different depending on the context of the work. I recently watched a video of some guy in the middle of nowhere who builds an underground pool with nothing but a stick. I thought to myself, “this is the fittest guy on Earth.” But, he would for sure not win the Crossfit games.
So, how can we come up with a definition of fitness or health that can actually be measured and/or applied across a broad range of environments? I’m not sure if it is actually possible. Context will always matter, and humans adapt very specifically according to their environment. This is why I want to talk more about stress and one’s ability to cope as being a better representation of health and/or fitness.
Your body doesn’t necessarily know what specific stressors are. It just responds to stress with the stress response, which is just a sympathetic response from your nervous system. I think this is crucial because it applies across all environments. Running from a tiger centuries ago is physiologically identical to lifting a barbell over your head when it comes to stress. This is why I think stress gives us a good representation to work with.
We use exercise and create healthy habits to make ourselves more resilient to stress and help manage stress. Exercise is a way to create a stress response but more importantly come down from that stress response to a more parasympathetic state (rest and digest). People who are chronically stressed and experience the negative symptoms associated with that don’t know how to turn off their stress response. Going into the physiology of stress would take way too long and there’s people way smarter than me that do that. One of the all-time greatest books on stress is Why Zebras Don’t Get Ulcers by Robert Sapolsky. Basically, if you don’t know how to turn off the stress response you are going to experience an increased likelihood of many physiological and psychological consequences long-term. Elevated heart rate and blood pressure, weakened immune system, likelihood of being overweight, depression, diabetes, just to name a few. Stress negatively contributes to pretty much any disease you wish not to have.
Exercise and fitness are ways we artificially create environments that help us manage stress. Stress isn’t the bad part, it’s the lack of ability to create the stress response and turn it back off. Bringing in some predictability in the context of exercise and the gym is a way we can work on managing stress. Meditation, having good friends and family are additional ways to help us better deal with stress.
Using this representation for health and fitness can give us a broader framework to work with. With this representation we can see how people that we might typically think of as being very healthy might not quite be so. I remember reading way back about gardening and farming being the healthiest occupations. This is low stress and pretty easy to recover from. Reaching to the far edges of performance probably isn’t the healthiest path long-term. Same with idea of taking steroids and putting on insane amounts of muscle mass. We all know small dogs live longer. Humans are no different.
If we can create better habits that help us manage stress, we are likely to become healthier. Meaning, we can decrease the likelihood of being diagnosed with various diseases and negative physiological and psychological disorders later on. This representation doesn’t include how sexy your muscles look (though, if that’s your goal, I’m with you!), but it takes into the account the things that really matter. This representation is comprehensive, which is why I think it works. If there is a better definition or representation out there, I am all ears.