This question is with regard to Rule 4, player equipment.

There is a growing market for wearable health and fitness monitors in the form of wristbands/bracelets. They monitor activity including heart rate, temp and sweat levels. Jawbone and FitBit are two of the leading manufacturers. And the prices are dropping so coaches and referees will begin to see these devices more frequently. Will these health monitors be classified as jewelry and therefore banned from play? Thank you.

Answer (November 27, 2013):
My personal belief is yes, these devices should be classified as jewelry and treated as such by the referee in any case involving their use in an actual game. However, in practice this question will will have to be answered on a case-by-case basis by the individual referee on the match. Both pieces of equipment involve wristbands that could catch on the player’s equipment or that of an opponent, leading to injury for all involved, thus violating the principle behind Law 4’s requirement that no jewelry be worn.

Either of those pieces of equipment would be fine for training, but not for competition.

And just to be certain, I checked my answer with some folks who are still active. Amazing how we still agree:

It’s a tricky question that [one of my friends] actually posed to USSF back in September when a WPS player attempted to wear such a heart monitor device and was refused by the referee based on a decision that it was jewelry. However, subsequently, it was attempted again (don’t know whether it was by the same player or not) and was allowed by another referee who decided it was “medical” and could be worn if wrapped and was safe. I asked what (if anything) had been said or relayed to WPS referees as a guideline on the issue. The replay was that there was no formal “ruling” but that USSF had communicated to the USWNT in the past that the devices could be worn so long as they are deemed safe by the referee.

One can only assume that what is OK for the USWNT is good for everyone else and that the argument is persuasive that, although jewelry, the devices are medical in nature and should be approached in the same way as is done with medical alert bracelets.