S.E.S. , in that order.
We have been preaching this mnemonic for a decade now here at TGG. Skill first, then endurance, then strength. In other words, first move correctly/well, then move often (build a robust amount of endurance on that skill that you can maintain it throughout your activity without losing the skilled movement without fatiguing), then add strength to this patterned movement. Then rinse and repeat; add a higher skill, add endurance, add strength. Rinse repeat.
We tell this one to our athletes, distance runners in particular, because it is no surprise that most injuries come in the later miles, when fatigue sets in, and compensations have to make up the difference if the run continues. This is necessary and protective, but the wise choice is to never exceed the fatigue, but always be inching the endurance forward.
The question is, do you know where your risk threshold lives ? When are you moving the safety meter past the safe zone and into the risk zone ? Your tightness or pain, if you are lucky, and paying attention, may be your "check engine light" moment, again, if you are paying attention. Never dismiss the benefit of a 2 minute walk in the later part of a long run when a symptom creeps in, it just might get you enough recovery to push out that last 3-4 miles with the symptoms shut down again. If you are lucky. Listen to your body, it is your job.
From the study below:
"In conclusion, NOVICE runners showed larger kinematic adjustments when exhausted than COMPETITIVE (distance) runners. This may affect their running performance and should be taken into account when assessing a runner's injury risk."
-Shawn Allen, one of the gait guys
Sports Biomech. 2017 Jul 21:1-11. doi: 10.1080/14763141.2017.1347193. [Epub ahead of print] Novice runners show greater changes in kinematics with fatigue compared with competitive runners. Maas E1, De Bie J1, Vanfleteren R1, Hoogkamer W2, Vanwanseele B1.