Someone recently reached this very website by googling the search term "how to relax when punching". They didn't stay long (under 1 second), which is probably because the answer to their question obviously didn't exist here…until now!
HOW TO RELAX WHEN PUNCHING
Step 1: Clear your head. Stop worrying about work. Forget about the kids. Right now, there's only this punch. Just you and the punch.
Step 2: Breath.
Step 3: As you wind up to punch, try picturing the person you're about to punch in their underwear! They look pretty silly don't they? Feel better? You're gunna do fine!
Step 4: Contact. This is the most crucial time of the punch in which to relax. I cannot stress this enough: CHILL OUT, otherwise you may mess up punching.
Step 5: Follow through. Congrats! The hard part is over with, though it is still important to remain relaxed. Try picturing the person you just punched in their underwear again. What a goof, huh?
Guess what? You're done! Punch complete. Don't you feel great? And hey, you didn't do half bad either! You stayed relaxed all through that punch and it showed! :)