Track a workout without wearing the watch

If i connect a chest strap heart rate monitor to my apple watch and start a workout then take the watch off and have the watch in range of me and the chest strap will the data still get transmitted to the workout and give kj and heart rate data or does the watch need to be on and unlocked to give the data. Reason for this is I want to get heart rate data while playing beach volleyball on my watch but i don’t want sand jamming up the digital crown