What am I dealing with? Fingers cramping shut

Full day outside today, climbed 14-15 routes over 6.5 hours. By the last 90 minutes the middle finger in my left hand was cramping shut on my palm and required manually pulling it open again. The sensation was uncomfortable but not painful. Placing the hand on a hold and loading the fingers was almost a relief (like the finger wanted to pull closed) but this would trigger another cramp shut. By the last 30 min, the thumb in my left hand and my right middle finger were starting to do the same and I called it a day. There was little to no forearm pump. Anybody know what this is called and what I can do to prevent? Never had this issue in 9+ years climbing.

Ate decent food throughout the day and felt well energized. Maybe was a bit low on water intake but probably 60+ oz on a cool spring day with 1 electrolyte tablet. Average caffeine intake for me (200-300mg) for the day, mostly in the morning. 

Sounds like pretty standard fatigue+dehydration. Not much else you can do besides water and electrolytes. Avoiding coffee might help, since it's a diuretic. Making a concerted effort to hydrate the day before will also be fairly preventative. Personally, I've found stretching the cramping muscle throughout the day can also reduce the severity of cramps. Just keep your forearms stretched and loose - rolling it out on a lacrosse ball certainly wouldn't hurt, either. I used to have pretty consistent cramping too, but religiously doing the above went a long way.

slo ta wrote:

Avoiding coffee might help, since it's a diuretic.

This is not true, and I'm not trying to attack you.  It's something people (including me) have said a lot, even doctors and scientists.  However, much re-examination has determined that while caffeine is indeed a diuretic, the amount of water one consumes from coffee offsets the effect of the caffeine, and even leads to a net positive effect on hydration, though not as good an effect as drinking water.  Overconsumption of caffeine can still be an issue though.  I also heard that the old wisdom of coffee being a diuretic was based on a study of three people from 1928, but I'm not smart enough to confirm that.

https://pmc.ncbi.nlm.nih.gov/articles/PMC3886980/

OP, slo ta's post has good advice.  I'm just being that dork who just learned something neat and wants to tell people.  :)

While 1,7L (sorry, you Yanks and Brits and your completely insane measuring systems…) is not ridiculously low daily consumption, on a big day out it’s still not much.

Worth looking into your consumption pattern as well. Was this amount gulped down in a few sessions or spread out during the day? Our bodies can’t really handle a lot of water at once, it just goes straight to the bladder.

Agree, it may be pretty typical cramping. Usually, more water, more electrolytes is the solution for prevention. Sounds like a lot of output over that time, try doubling your water intake and see if that alone fixes it. For electrolytes, it's mainly sodium you need, but potassium, magnesium, and calcium can be the limiting factors too. Insufficient calories can play a role too - I noticed pretty stark improvements once I started adding performance gels to my multipitch days.

Once the cramps start, you may have luck with a shot of apple cider vinegar or pickle juice - the acetic acid stimulates the nervous system connection directly through receptors in the mouth, so it's one of few options for treating cramps after they start.

Manual therapy (massage, percussion massage gun) through the day helps stave off the inevitable. More low level endurance training may help in preventing it. Good luck!