Failure on near-limit routes often seems to result from the fatiguing of the forearm muscles and your subsequent inability to climb on through the pain and cramps of a deepening pump.
Success on a burley boulder problem or severe crux sequence often seems to come down to having rock solid lockoff strength and a vice-like grip. While you may only call on such top-end strength on the most physical climbing m
There's not really any way around it. You gotta be fit to climb hard. This sport requires power, endurance and control from numerous muscles, tendons, and ligaments - a full body exercise.
