Nothing makes me cringe more* than watching a climber walk up to the crag and start their day on a steep, crimpy route with powerful cruxes. I usually have to look away for fear I’ll actually see his tendons explode, and never want to touch another crimp again. From observing hundreds of climbers over the course of many years, I can confidently say it appears that warming up may be one of the most underrated, and least understood, aspects of a day of casual cragging. In reality, the concept is quite simple, and it’s generally agreed on by folks with much more knowledge than myself that a proper warm up consists of three to four roped routes, starting off easy and getting progressively more difficult.
*(Actually, there is one other thing: watching a climber taking falls and slamming hard into the wall because their belayer doesn’t have a clue how to give a soft catch, instead of jumping they dig in and brace themselves like they are preparing to take a hit from an NFL linebacker.)
At a scientific level, warming up dilates blood vessels, which allows blood to flow more freely to your muscles, and they are going to need all the oxygen they can get if you plan on getting on something challenging that day. It also gets connective tissue ready to take the loads you want to put on them.
Some people mistakenly state that they don’t like to warmup, because once they get done with it, they are too tired to climb anything else. Chances are, they are going about it wrong, and climbing on routes far too difficult to be considered “a warm up.” According to climbing coach and sensei Justen Sjong, who I’ve been fortunate to have a session with, the first route you do should be so easy that as soon as you lower off, you can take a TR lap on it right away, correcting any mistakes you made the first time up, and putting yourself in the proper mind set and flow for the day. If the first route is too hard to do a second lap on without taking a rest in between, then it’s not a proper warm up.
Numerous training books out there cover the topic of warming up, from the Self Coached Climber, to SCFTRTRTFCS. The SCC guys say you should start on a route that is 2 to 4 number grades below your redpoint goal for the day. So if you are aiming for 12a, that might mean your first route is a 5.8 or 5.9. Andrew Bisharat says your last warm up should be about a number grade below your project level, his recommend progression for someone working 12b would be something like 10a, 10d, 11b. He also notes that your last warm up should get you somewhat pumped, not to the point of failure, but you should have to try on this one.
And then comes a crucial part, take some rest! I usually wait about twenty to thirty minutes after warming up before getting on anything harder. This gives my body a chance to recover fully from the warm up and be ready to try hard!
Obviously, there is a bit of a fine art to the process, but that’s part of the game. I also find it key to remember that it’s just a warm up, which is especially helpful when vising areas where you aren’t familiar with the climbs and/or grades. If you get on something too hard, don’t be afraid to pull on draws or hang and lower off to do something else. Nothing will ruin your day more than a flash pump, and nothing will ruin your season more than an injury because you rushed or omitted a warmup and your body wasn’t yet ready for the stresses you wanted to put on it.