Tightness isn't what you think. We tend to say that if a muscle feels tight it's shortened and you need to stretch it, or it's weak and you need to strengthen it or it's a knot and you need to release it.
All are kinda wrong.
We can't actually tell if something is tight, by our own definition of what we think "tight" is. The muscle doesn't get shorter or knotted up.
First of all, having pain isn't associated with a muscle being tight and stiff. It's not a sign of how the muscle is doing, but it can tell us how we feel our muscles are doing.
It's a nervous system thing, like a sensitivity or perception of threat. It can show up for a variety of reasons. But usually it's just a sign that you need to do something different, like moving more.
We're often told that we're tight or stiff and our expectations and conditions shape how we feel. And a lot of times we make something out of nothing. When we're constantly fed the narrative that we're stiff as a board and need to stretch and mobilize, we tend to take this to heart.
One study found that“Stretching interventions with 3- to 8-week duration do not seem to change either the muscle or the tendon properties, although it increases the extensibility and tolerance to a greater tensile force. Adaptations to chronic stretching protocols shorter than 8 weeks seem to mostly occur at a sensory level ." (1)
So essentially stretching made us "feel" better in the short term but caused no meaningful structural change to muscles and tendons.
Anecdotally, I find that the people that are usually stretching, foam rolling, and mobilizing the most are those that actually feel the tightest.
We even tend to go overboard pulling on the tight and sensitive area and obsessively stretching it, making things worse. Sometimes we need to just leave it alone. A muscle may feel tight when it's simply fatigued (like how you feel during DOMS or delayed-onset muscle soreness), and stretching it can actually contribute further to this fatigue.
In conclusion, muscles and joints can feel tight when we don't use them, but they can also feel tight when we're told they're tight. My recommendation is just to move more and sometimes just let an irritated tissue calm down. Don't buy into the notion that you're full of knots that have to be released in order for you to function.
Train to a good range of motion and move often. That's all there is to it. There's nothing to fix or release. Don't let perceptions of other people affect how you feel.
To your good health,
1. Freitas SR, Mendes B, Le Sant G, Andrade RJ, Nordez A, Milanovic Z. Can chronic stretching change the muscle-tendon mechanical properties? A review. Scandinavian journal of medicine & science in sports. 2018; 28(3):794-806.