The biggest thing with the tattoo is keeping it clean and healthy.
If you’re not going to sweat to much (as in doing a massive session) it should be ok, but personally I’ve always waited a minimum of a week sometimes two before I get back into things.

Mostly because I want the tattoo to heal and be as crisp as possible, but also because I tend to scab a little as I heal so would rather wait till that’s sorted than inflict it on my training partners or randoms at the gym.

I recommend taking off a full two weeks for large work, you will wear it the rest of your life, whats two weeks?
there is alot that can go wrong, scratched or irritated by mat, machine, anything, too much sweat, bacteria, just too many things that can lead to a poorly healed piece

if you have been working out a long time, two weeks wont mak a hill of beans difference…………..not properly healing that tattoo would though

The profuse sweating is a far bigger concern than stretching the skin a little. There is absolutely no reason at all why you can’t go for a walk or do something equally low-impact. You don’t need to, nor should you, keep your upper body fixed or stationary for a week or even a day for that matter. The idea is simply to try and avoid excessive stretching of the skin and for what it’s worth, I haven’t seen a shred of medical evidence to support the claims that doing so can harm a new tat anyway.