30 min
Make a plan before leaving the ground, then check it against what happened
Pick one easy boulder problem and put the group in front of it.
Introduce the word beta: the plan for how you climb something. Two people's beta can be different and both be right.
Ask them to point out, on the wall:
Then break it into three parts and talk through each: getting off the ground, moving through the middle, finishing. Ask which part looks hardest. That one has a name too, the crux.
Air climb it. Standing on the ground they mime the moves in order and say them out loud: "right hand here, left foot there."
Then split across two problems, a coach on each. Ten athletes queueing for one boulder is nine of them watching, and reading is what you want them doing. Two problems is two queues of five and twice as much reading.
They climb it, and afterwards you ask what they got right and what they would change. The comparison is the lesson, not the reading. Whoever is not climbing at their problem is reading the next one out loud to the person after them.
Swap the groups onto the other problem, and this time ask them to call the crux before anybody climbs.
They just climb without reading. Stand between them and the wall. Make reading the only thing available for sixty seconds.
Every answer is "I don't know." Drop to one question with two answers: "does your right hand or your left go first?" Guessing is fine. Checking it afterwards is the point.