How hard do you other boxers clench your fist while sparring/competing?

[Trrmo]

the title says it

[Pork Chop]

uh, just at the moment of impact, the rest of the time they're relaxed.
Might tense them a bit when I first put on the gloves to make sure I can make a good fist.
When you make impact, you tense as hard as you gotta to maintain proper structure.
Not sure how to quantify it.

[angus the bull]

Always have it tensed just before impact. When i'm moving around i have an open glove.

[sterling]

Always have it tensed just before impact. When i'm moving around i have an open glove.

same here

[jberg]

no point wasting energy by keeping yourself tense
also, ive found that by clenching my fists at the last minute, the surge of energy adds to momentum and just helps my punches get sting.
finally, when youre parrying and blocking you dont want clenched hands because it is bad for maneuverability

[JayCoe]

Just before impact. Your entire body is part of the punch, and your entire body is linked up muscle by muscle. When one muscle is tensed it sets off a reaction for other muscles to tense or relax. Making a first actually involves alot of your arm to some extent, ok, so your muscles aren't all fully tensed but they're in action which means there's resistance for the punch to drive forward, in essence, you're slowing down your punch by putting your muscles against themselves. Conserving energy has little to do with it, i'm sure it does save some energy but it's more about maintaining that free flow of energy from the ground through your legs up your body to your fist.

Also, don't tighten your fist as hard as possible. People think a tighter fist upon impact means a great punch, in reality you're more prone to injury if your fist is properly solid on impact and it accounts for almost nothing because of the gloves. Put your hand in gloves and then clench a first like normal, and then clench a fist really tight, due to the glove it makes almost no-impact, in a bare knuckle fight however it does pronounce the knuckles more.

[fraidycat]

I clench mine super****inghard at the moment of impact. Maybe I'm overclenching but I've never been asked about it. I have very, very strong hands, though.