Apple watch, will it work "loose"

I like to wear my watches on the looser side, a tight watch really bugs me.



But the apple watch has an optical HR sensor... so logically, if its not pressed against skin, can't get a reading.



Or can it?



I guess the best option is to use the leather or silicone strap, since the metal bracelet will be uncomfortable worn tight...



Anyone have experience with these types of sensors>?

via ehMac.ca http://ift.tt/1w180RP