As a coach one of my foundation principles is meeting people where they are at. This is in regards to everything we do and are, both in and out of the gym. Stress, capabilities, training history, genetics, injuries, and the list goes on. There are no two people who are exactly the same so why then would we try to blanket our training as a one size fits all. Even if you took two identical twins, how they live life will drastically change the way they might respond to exercise.
Why then would we attach a negative connotation like regression to exercise when we're using it as a tool to enhance our health, life, or performance. If we are truly meeting people where they are at and providing a stimulus aka an exercise or training modality to enhance their capabilities and make them better, how then is that a regression? If we break down what is needed to create improvement one of the pieces that is a must is progressive overload so by default, the term of using an exercise to create improvement, when done properly, is then itself a PROGRESSION. Science :)
Now don't get me wrong, this does not make me some overly positive coach or person who refuses to acknowledge negatives in exercise or training. However, when it comes to guiding people towards whatever goal that has been determined, is not then every form exercise we are doing is trying to move someone forward? Take for instance some one who has a lower body injury and our goal is to bring them back to "full go" by being able to do anything they need or want to do, for this example, let's use a soccer player. They need to run, jump, change direction, display strength, power, absorb force, etc. So if we are returning them to sport and taking them from injured status of not being able to walk pain free to walking pain free, is that not a progression? Instead we have a tendency to compare them to where they are at to where they or we want them to be. There is nothing wrong with that but if the end goal is our marker of success then it doesn't do the work and milestones it takes to improve justice.
Where would these comparisons end? Would it have to be something we have done before? So if we could run a certain time is anything slower a regression? Or is it some exercise that has been deemed the "standard" and anything less is a regression? So just because someone can't back squat for example because it's programmed, does that mean a goblet squat is regression or is it a modification aka PROGRESSION to get them closer to a potential goal? The number of factors and reasons we could debate this could be endless.
So why make a big deal about this, it's just a term, who cares. To that I would say you're right, as long as that coach and athlete have a common language, call it what ever you want. However, we know the benefits of positive reinforcement and attachment so why not set people up for success by attaching a positive outlook to the work they are putting in? So what you can't back squat, but if you were able to perform a variation of a squatting pattern with more weight, better technique, or larger range of motion than you were yesterday how in the world is that a regression?! Celebrate the wins and work you are doing by calling it what it is, progress.
Life and training can be hard enough as it is without attaching negative terms towards forward progress and to be honest, if you don't like the term or the way I use it, it's no skin of my back as it doesn't change how I feel or how I'll use it. That said, empathize with your clients and athletes who are using the gym as a place to get better and as a coach you tell them "here's a regression because you can't do what's expected." How might that feel or be received? Don't underestimate the mental or emotional piece, words matter and as a coach, those words have impact. So next time you need to modify training and meet someone where they're at ask yourself, "is what we're about to do moving them closer to the intent?" If so, then give credit where credit is due and call it the progression that it is.