Russian Twists: Sit on the floor with knees bent, lean back slightly, and twist your torso to touch the floor on each side with a weight or without.
Bicycle Crunches: Lie on your back, lift your legs and shoulders off the ground, and alternate bringing opposite elbows and knees together.
Plank with Hip Dips: Start in a forearm plank position, then rotate your hips to touch the ground on one side, then the other, alternating sides.
Side Plank: Lie on your side with your elbow directly beneath your shoulder, lift your hips off the ground, and hold. Repeat on the other side.
Mountain Climbers: From a plank position, bring one knee towards your chest, then quickly switch legs as if you're running in place.
Bird Dog: On your hands and knees, extend one arm and the opposite leg straight out, hold briefly, then switch sides.
Bridge: Lie on your back with knees bent, feet flat on the floor, lift your hips towards the ceiling, and hold briefly before lowering.
Standing Side Crunch: Stand with feet hip-width apart, lift one knee towards your elbow on the same side, then switch sides.
Superman: Lie face down, extend your arms and legs off the ground simultaneously, hold briefly, then lower back down.
Dead Bug: Lie on your back with arms extended towards the ceiling, bend your knees at 90 degrees, and extend one leg out while lowering the opposite arm towards the floor.