Upper calf locks up during bike

 Scott welcome to BT.

I don't know what your training situation is but  FWIW.......

I cramp-up in the calf, hams, thighs after I have had a few hard day of training. It used to happen alot when I was playing waterpolo in my youth as well.  I have found the main reason for me is a lack of sodium and /or potassium in my diet.  Table salt is not something you would see in our house.  Most canned or processed foods these day are chocked with salt and you would get the required amount in you typical diet without having to add any extra. During the summer when it is hot and humid (excesive sweating) or when I ramp up my training I have added some extra salt.  I also try to increase my intake of potassium rich foods, mainly  bananas. I am by no means an expert in the field of nutrition, but my wife is and I tend to listen to her on these matters.

Mike

I had the same problem last season, but mid-calf.  Being a geek, I did some research on-line and found, surprisingly enough, that "they" (with they = medical community) do not particularly know why cramps happen, but suspect it is due to a deficiency of electrolytes (sp?) and water ... and that stretching seems to alleviate the problems.

All of that is a big "Well, duh!" - but I say that just to say that there is no concrete answer of why cramps happen and where.  We know that water, salt + other electrolytes appears to help so beyond the stretching prior to the race and remaining hydrated with a sports drink (not just water), you might want to try these two things that were suggested to me by one of our TNT coaches:

1) During the swim, keep your feet "loose" and remember to kick from your hips.  This will lessen the use of your calves during the swim + keep them fresh for the bike.

2) During your bike, keep your heel down - particularly through the 9 to 4 o'clock part of the stroke. This will help stretch out your calves during their use on the bike as well as prepare them for the run.

Hope this helps.