The SEAL youtube yesterday tells a lot about physical endurance. Sure, for the obstacle course (which SEALS in training run through many times) plenty of strength is needed too, especially grip. That guy doing the obstacle course was plenty strong but he flunked. Of course, the physical training for SEALS includes much more than that obstacle course but it's one component.
One of the things I've learned, even at my age, is that 60-75 minutes of workout daily does build endurance if only as a side effect. Strength is great, but for daily life endurance is what we want to maintain first.
What's the trademark Maggie's Farm 6-day/week fitness routine? Readers know: 2 hrs mostly pushing weight, 2 hrs cardio (real cardio), 2+ hrs calisthenics. Plus appropriate nutrition and one day of rest, "rest" meaning just walking etc.