Core work … oh that hurt

I do a sled push in which I brace my core, stand vertical through the hips, pull in my stomach and push only with my arms. I did this a bunch yesterday. Not huge weight, just 250lbs. I went down to 205lbs for hand over hand pulls using a rope in the same braced position. Last night I had to shovel snow and oh my god did that hurt. It got to an 8 out of 10 on the pain scale. I was surprised I could sleep. Little leery of exercise today but it’s kind of ok now.