The problem: a short carry that ends many runs
At Zombillion, the ammo-crate carry looks simple: lift a 20 kg crate, walk 20 metres, set it down, and keep moving. It is not. The obstacle arrives after 6 km of mud, low walls and uneven ground, so the limiting factor is rarely raw strength; it is grip endurance. Hands that have already been soaked, chilled and scraped lose their hold faster than the legs lose power. The result is a cluster of dropped crates, stalled queues and runners who finish the event with forearms that feel inflated.
The cause: friction, leverage and wet handles
The crate has side cutouts rather than a bar, which forces a pinch grip. Pinch grip relies on the thumb pad and the first two fingers, and those tissues fatigue quickly when the load swings. Mud makes the cutouts slick, so the hand must squeeze harder just to maintain the same friction. Add a low carry position and the crate’s centre of mass pulls the shoulders forward, increasing the torque on the wrists. The obstacle is not a test of deadlift strength; it is a test of how long the forearms can keep a wet pinch grip closed while the rest of the body is already tired.
The solution: train the carry in the conditions that break it
The fix is specific. Runners should practise a 20 kg pinch-grip carry with wet hands, not dry ones, and should do it after a short run so the forearms arrive pre-fatigued. A useful progression is three rounds of 20 metres with a 60-second rest, then two rounds with a 30-second rest. The goal is not to increase load quickly; it is to reduce recovery time while keeping the crate stable. Chalk helps in training but is often unavailable on course, so the final sessions should be chalk-free.
- Grip: Use the cutouts, not the top edge; the top edge slips when the crate tilts.
- Carry height: Keep the crate at mid-thigh to reduce shoulder torque, but not so low that it swings against the knees.
- Hand care: Tape the thumb pads for long training carries, then remove the tape for short course-simulation sets so the skin adapts.
- Pacing: Start the carry at 70% effort; the first five metres should feel too easy.
The result: fewer drops and a faster queue
When runners rehearse the wet pinch grip under fatigue, the obstacle changes character. The crate still feels heavy, but the hands stop opening involuntarily at the ten-metre mark. Event organisers also benefit: fewer dropped crates mean shorter queues and fewer volunteers needed to reset the lane. For anyone preparing for the full zombillion course, the ammo-crate carry is a small obstacle with an outsized cost. Train the grip in the wet, after a run, and the 20 metres become a controlled walk rather than a negotiation with gravity.