The first was KB suitcase carries using a heavy weight. Suitcase carries is one of many loaded carrying variations that I love as they are excellent functional exercises that transfer well to real world application.
When doing these keep a nice tall posture with shoulders square and walk. Your core is gonna work harder to stabilize as you try to resist lateral flexion/ side bending.
Then I did the Cross Body Mountain Climber which is one of my favorite variations of the traditional mountain climber. While in a plank position keeping your spine neutral, hands underneath your shoulders. Bring each knee into hip flexion/towards the opposite shoulder while keeping a flat back.
Circuit in order:
1 arm heavy KB/DB suitcase carry 30sec each left and right.
15sec rest
Cross body mountain climbers (slow) 30sec
15 sec rest
Jump rope 30sec
15sec rest
Complete circuit 4 times through. This is a nice bit of conditioning to plug in at the end of your strength training session and will build a strong core and melt away some body fat to give you some lean looking abs.