This study tests the randomized re-opening of training facilities in Norway in relation to the COVID-19 pandemic. The investigators will use the recently developed concept of rapid-cycle randomized implementation to assure fast and safe re-introduction of training facilities by randomized testing of access restriction and measure virus exposure and immunity as well as clinical disease during the intervention to enable safe and timely downgrading of COVID-19 restrictions.

Members of training facilities in Norway age 18 to 64 years without COVID-19 related comorbidity will after informed consent be randomised to either access to training or no access in a first 2-week cycle. Testing for COVID-19 and ascertainment of clinical disease will be performed after the first cycle. If there is no clinically meaningful difference between the arms, new cycles may be implemented subsequently, e.g. with less distancing restrictions or wider age groups.

Inclusion Criteria:

• all members of participating training facilities age 18 years or older who are not at increased risk for severe COVID-19 disease (see www.fhi.no for criteria) are eligible for participation if they

  • plan to use the training facility regularly during the project period
  • are willing to adhere to training policies during the project
  • accept assessment of project endpoints
  • approve handling of data for the project

Exclusion Criteria:

• COVId-19 related comorbidity
• Age below 18 years or above 64 years