That all comes down to understanding, and not being distracted from, what is actually driving progress. In this case, it's adaptation that's driving progress.
The first thing we have to understand is that the body is, basically, a whole bunch of cycles running at different speeds. Cycles breaking things down, and cycles repairing and building things
The first thing we have to understand is that the body is, basically, a whole bunch of cycles running at different speeds. Cycles breaking things down, and cycles repairing and building things.
When we lose weight, the tearing down cycles speed up. The building cycles slow down.
When we gain weight, the cycles speed up.
Through all systems. The rate and ratios that they slow down and speed up are largely determined by genetic and environmental factors, with your body determining what to do by what it deems necessary for survival and to deal with whatever stressors it's currently facing. Most of this is beyond our control.
When we gain weight, cycles speed up. We gain everything, not just fat. Unfortunately, a disproportionate amount of the gain IS fat.
When we lose weight, cycles slow down, our body just starts throwing stuff out. Unfortunately, a significant amount of this is not fat. Worse, unless you have extreme levels of fat deposits, half, or more, of that 10 pounds you lose may not be fat.
It's lost muscle and bone. Again, all things left to chance, the ratio that this happens in is mostly determined by genetic and other factors beyond our control.
Luckily, one of the few areas we do have control over is pretty damn powerful.
That, is where adaptation comes in. We can leverage our bodies to use adaptation to keep the tissue we want. Essentially, with the activities we choose, while losing or maintaining weight, we are telling our body, "Hey, you need to hang on to this muscle and bone. We're gonna need it.
Tissue adaptation is where our focus should stay in determining whether a workout can even accomplish what we want it to.
So, if adaption is driving progress, what is driving adaptation? That's easy. Stress. Stress drives adaption.
It’s that simple. Yet, most people's focus gets lost on what specific exercise they are doing, what equipment they are using, how hard they are breathing, how many reps they are doing, how "badass" their workout feels, how much it "destroys" them, etc. In all actuality, none of that matters, or at least, it matters very little.
The problem with all the above, is that they aren't very good insights into this very simple question, "How much stress am I applying to the tissue I'm trying to keep?" You have to stress a tissue somewhere in the neighborhood of failure to cause it to adapt. I say neighborhood, because it, like everything in human physiology, it works in a range. Also, always going to failure is a good way to run yourself into the ground and miss your long term goals.
Studies show 90-95% of regular exercisers are not effectively stressing their muscle, bone, or connective tissue. That has huge implications for health and quality of life, aside from just dictating what type of tissue we are keeping/building and, therefore, losing.
How do we not fall victim to this?
By ruthlessly focusing on what matters - the application of stress to a tissue past a certain threshold, and understanding that everything else is about psychological variety. That is important in it's own right, but it should not distract us from where our benefits are coming from.
And that's why this workout generator focuses on 2 things:
Now, you are wondering, "Well, how do we do that?"
That's where RPE comes in.