You mentioned kitchen counter push-ups... that's incline push-ups, which are easier for starters. But if the counter is too high, you might not be using your core much... try a lower spot like a table edge. Keeping your body straight helps with the calm feeling. I learned that when my back got sore... tweaking the height fixed it. So maybe check your form.

Back in Texas, we always mixed coarse gravel with a bit of sand for drainage. That combo kept my fence standing through heavy rains.