Just tried to do it and realized not only I need to sustain my body movement with my arms, it also take a lot of strength to tighten my core in order to keep myself into that reversed plank position. As I'm laying myself down, I try to exhale but my stomach went weaken. I tried to reverse my breathe pacing, but my arms lose strength. Do you have a particular breathing method whilst doing this? Appreciate if you can further elaborate this. Cheers and another upvote for taking time to reply me!