Blue vest thingy's

[chicky17]

This is probably a stupid thread, but just wondering if anyone knew what those blue strappy things some of the players wore under the gurenseys agasinst the saints are? Tim Clarke and Sam Mitchell were a couple to wear them? what are they and what are they supposed to do? heart rate monitors?
Didn't get to see much of the game (bugger), but the little i did see (when we were getting pumped) big Robbie Campbell looked alright. did he have much game time?

 

[My Man Croad]

They calculated the amount of ground those particular players covered.

Tim Clarke would of covered plenty of ground considering he was running around like a headless chook.

 

[Yardie]

They were picking up heart rate, the amount of ground covered and some other stuff I can't remember.

 

[ViperV10]

All clubs were using them, some data for the statisticians to work with.