Having experience of exercise allows someone to make an informed decision about what type of exercise might be best for them or what they would like to pursue next or what the ideal amount of exercise for them would be. This would not be seen as a barrier to proper exercise but instead an encouragement. All other options would definitely be common barriers to exercise as they are all negative.
You should shelter in place under these circumstances. Your office is a safe enough environment that you would encounter more hazards by leaving rather than sheltering in place.
