Never get bored, but get bigger and stronger, and use every dang piece of equipment in the gym. Add arms to whatever day you like. I like heavy ez curls and heavy skull crushers to day 2 (1st UB day of the week) and cable bi and tri on day 4 (second upper body day). I usually do reverse squats and other hip flexor work plus calves to finish off lower body days. Core work I do during rest periods because I have puppy brain and can't sit still for two minutes but up to you when you mix in abs/core/accessories. Lower body warm-up options: Treadmill/bike/rower 5-10min Hip mobility exercises Kettlebell swings 2×10 Box jumps 2×4 Lat lunge 1-2×10 Curtsy Lunges 1-2×10 Single leg deadlift 1-2×10 Sled push/pull ×2 Lower body finisher options: Split Squat jumps Reverse squats Calf raises Upper body warm-up options: Walk/bike/rower Arm circles Shoulder dislocation Lu raises Lock 3 Banded pull aparts w/ 5-10 second holds Upside down, kettlebell presses