If you've ever trained with me, then you are well acquainted with loaded carries. Whether it be rack carries, overhead carries, farmers walks, or any of the dozen other ones in my arsenal, you know what's up.
The importance of implementing compound movements into training is something I constantly hammer on. There's nothing like working almost every muscle in your body in a single movement. However, doing a compound movement and taking it for a walk is next level. Now you've taken a full body compound movement and turned it into something that's going to improve your stability, posture, and conditioning. The abdominal bracing involved with a solid carry will force all of the stabilizers in your core to fire, add in some uneven weights and now you're working muscles associated with anti-rotation and flexion.
I'm a huge fan of efficiency, and results don't lie. All of my clients have made huge progress in their mobility, strength, and aesthetics in a surprisingly short amount of time.
There is simply not anything better. Carrying is a fundamental movement that all humans do on a daily basis. Why not train in the gym with a style that's going to carry over into the real world such a big way?