Taking ibuprofen is dangerous for a climber because it doesn't offer any benefit and may be causing disagreeable physical damage instead, particularly to the intestines. There is no reason to use it before excercise but many reasons to avoid using ibuprofen!
Ibuprofen side effects include nausea, drowsiness, and general fatigue. If you are a climber, you do not want to experience drowsiness or nausea. These can be dangerous as they impaire you and put you at risk of falling or getting lost.
