Back is feeling better. Finished off my lower-body yesterday:

Reverse hyper single leg curls: 6 plates x 3 x 15

10 hanging leg raises, 2 sets of 10 with the ab wheel (kneeling), 30 crunches

This morning right after waking up, I jogged out to Heart Attack Hill and did 1 backwards uphill jog followed by 1 sprint to the top.

4-min jump-rope round in the morning with high knees burnout in the last 30 seconds

Evening:

Squats

365 x 3

415 x 3

465 x 1, 2

Strip-sets of 405x3, 315x7, 225x8, 135x8, 50x10

Felt EXTREMELY heavy, but after racking the first single of 465 I decided I had more in me so I went for another set.

Held off on doing anything more to gauge how my back would feel. It started hurting about 20 minutes later, but in a way that feels like the muscles are wrenched vs the previous chronic low back pain I've historically had. Haven't trained legs or abs in more than a week since getting food poisoning.