MrGambinus wrote:
From my POV Goucher Needles is right. My experience when running with tucked butt (while anterior tilt is natural) is that you cramp up too much, lose efficiency and kinda isolate the hip flexors. The result is that you are too much running out of the lower leg and have way too high knee lift and reaching out with the legs.
Relax your body, run out of the hips and focus on the backwards extension of the hip, NOT the knee lift and forward part.
Too much sitting results in C Curve and back pain. J curve and running is the opposite! Try to hunch over a bit and bring your body into the C-position. Now do the opposite. Notice how your chest opens up? How do your lungs feel now in J position?
And the thing about quad dominance is not true at all.
Quad dominance is mainly seen in C shape runners.
Hunching over while pelvis remains neutral -> weight put on quads, try it out.
Sticking but out and running ->automatic slight forward lean, muscles activated are glutes and hips, try it out.
There is a difference in quads and hips. You will feel you hips in the most upper part of your leg burning when running while the quads are the thing you feel in cycling. Mainly the lower portion of the upper leg. Look at cyclist legs and you see the quads sticking out around the knee caps. THAT is the quads and you should not feel them a lot in distance running cause its inefficient.
This is the exact opposite of efficiency and proper form. It is nothing you see in the best of the best, and you need to use the simple parts of your mind and stop trying to be the smartest mind in the room. Telling someone to overload their hamstrings and relay solely on their posterior chain is criminal. The hamstrings are not a load bearing muscle group, they are NOT the main drivers of walking or running, that would be the quads. Food for thought.
The answer to the OP is simply complicated. Hold your lower abs to maintain proper body position. It is that simple in explanation. Doing it for 10 ten seconds or 2 hours is the complicated part. Training your body to handle this position is the job. You are working on being efficient not solely comfortable. The majority of the advice above is based on ease and comfort. The former is useless in all capacities when trying to to your best, it is never easy. Comfort comes from fitness and repetition. Do not over complicate the correction, it is hard enough to do on its merits.