One heavy bell, one long walk, and your core fighting the lean.
Brace your core and keep both shoulders level, do not let the weight pull you sideways.
Loading one side only turns a simple carry into an anti-lean battle, the traps and grip on the loaded side hold the bell while the core and back on the opposite side fire hard to stop the weight folding you sideways. Every step is a fight to stay symmetrical, one side at a time. It earns its place because almost nothing trains the side of the trunk this honestly, and the strength transfers straight to carrying anything heavy in one hand in real life.
The lopsided load forces your trunk to resist bending sideways, which hammers the deep core muscles two-handed carries barely touch. It is a core exercise disguised as a walk, with grip and trap work thrown in free.
Lighter than half your two-handed carry weight to start, the anti-lean demand is the hard part, not the grip. If your shoulder hitches up or your torso visibly tips, drop the load until you can walk tall and level.
Always, and match the time or distance exactly on each side. The entire benefit is symmetry, so give your weaker side the same work, or start with it while you are freshest.
