I just don’t get why the Whoop app needs to be open/in background at all times. Support keep telling me it’s because they use BLE but so do Garmin and Oura and they do not require the app to be open all the time. I personally do not like having my phone with me when I sleep. Support tell me I can store up to 14 days on the Whoop MG and sync at a later date but closing the app for 2 hours took 10 mins to sync. Every morning I open the Oura app and sync the evenings sleep in under a minute. Garmin is even quicker. Whoop could take over an hour or more if my initial tests are correct. Seems I might need to keep my phone in my bedroom at night 
Personally I think there is bad code in the Whoop transfer protocol and instead of addressing the issue they saying keep the app open. I will run some more checks but so far it seems my only option is to have the app open and my phone near me 24/7.
Anyone else think this is needless or have a good explanation as to why. Support are very vague. They can’t possibly be storing so much data it takes an age to sync.