Leg Cramps from Swimming

Mine usually cramp in the pool after a run, not the other way around like you stated.

But your first assumption is correct.  You use your calves in swimming to extend our feet for the kick, and obviously for the run as well.  Just a matter of overuse.  I would just do some calf stretches after all your workouts, and that should help.

BTW - chlorine wouldn't have any effect....

I can get them swimming and running but have solved the problem.

What works for me is to take electrolytes before I swim..I take 500 mg of sodium ie 2 Lava Salts and drink water with electrolytes in while I swim...ie nuuns.

When I run and I get them it is from not taking enough electrolytes again so I be sure I take more. 

I'm curious if you have tight calves? Many BT folks including me who get cramps I see a correlation between tight calf muscles that can cause Plantar Fasciitis and/or achillies tendinitises and getting cramps swimming and/or running. I find if I have knots in my calf muscles I'm much more likely to get cramps so I'm careful to work on the knots with the stick or get a massage or see my rolfer which addresses the why I think I get them.

Leg cramps from swimming are not due to electrolytes.   This has been debated elsewhere on this site, with scientific evidence to back it up (I'm trying no to hijack this thread too much )  but at least as a general rule, muscle cramps in one part of the body -like calves- it's often just one in swimming- are due to something with the muscle misfiring, usually caused from a muscle being forced to due something it's not trained enough to do like run down hills in a marathon when you trained for a flat marathon or from doing something that puts the body part in a position it's not supposed to be in. 

Getting back to the original topic at hand, the tradition calf cramps one gets in swimming is usually do to foot/ankle position. If you're pointing your toes towards the bottom of the pool, (basically you're at zero degrees plantar flexion or not much more than that- foot is at right angle with ankle), you may cramp up as it places the calf in a bad position.  If top of your foot is basically parallel with the bottom of the pool (aka tops of the feet to the floor that is a part of some yoga moves), your calf muscle will be much happier.   This website explains it much better than I can http://www.zoomers.net/new-thekick.htm 

I've had this happen to me before (my first to half IM swims for some reason, even though I had been swimming on and off for a decade before them).   It was clearly a technique thing.  If you look at the "kicks" of many triathletes, especially particularly skinny sub 45 year old men who come from a strong distance running background but no swim background (they are the perfect example in this case), you will see that their legs are going all over the place, toes not pointed correctly, and they tend to swim faster with the pull buoy.  And the ones I swim with tend to cramp up about every 2 workouts.  If you've got access to a coach or at least someone that's a swimmer first, ask them to look at your kick.  And yes, the kick is not all that important in tris- unless your lack of one or poor kick is killing your speed and wasting energy.

There's a lot of great info on this website, written by the guy that designed Zoomers- this fish thinks it makes a lot of sense-  http://www.zoomers.net/