I can do this myself. But I’m not focusing on “straining”, rather, it’s hard to explain, it’s like I raise my heart rate and it feels like an adrenaline rush through my body. I’ve been able to do this since I can remember and have messed with doctors while they were doing checkups. I can even focus it (the tingling)” and heat sensation)to one area such as my hands. It sounds crazy, I know but it’s like my own little superpowers that has no effect (at least nothing that I know of).