My organisation provides a gym on site for use by staff during and outside of working hours. Currently the rule is that there must always be a minimum of two people at one time but people have commented that this restricts times they can use it and some people would like to be able to use it after work and can't always get other people that want to stay, also some people come to use it during the working day but then can't because no-one else is available to. Weekend usage has also come up but again people can't use unless they can find another employee to come in with them. We have a small team on site 24/7 but they are often busy and snowed under and could not be relied upon to undertake regular checks on people in the gym due to their workload. We currently have a health questionnaire in place for people to complete prior to using the gym so manage that around any pre-existing conditions. Staff also get an induction on the use of the equipment before they are allowed to use it. Is it reasonable for people to sign a disclaimer that they would not hold the company liable for any injury or loss should they hurt themselves if using the gym on their own? After all, we're all grown adults?

You need something similar to a Lone Working Protocol. On the site I currently work we have a Security Point. After working hours in the gym, anyone using has to sign in at security and phone it at various times (I think half an hour is the limit). If not done so, then the guard goes to investigate. If the person forgot to phone then it is three strikes and out. Hope this helps point in the right direction.