You have plenty of options to keep yourself moving and motivated indoors! Working out at home is the new going to the gym. Why not try walking up and down the stairs a few times, use your chair or sofa to do squats or do a push up against your wall? There is plenty of opportunity to stay active indoors, it might just take a little more motivation than usual. See this blog for some easy at home work outs for beginners to get you into the swing of things: https://www.verywellfit.com/easy-workouts-for-beginners-3496020.
Isolation doesn’t mean just staying inside your home, you’re perfectly fine to go out into your garden and this will help you feel less trapped during this time. Why not try some light gardening? As well as being good exercise, being outside for a few hours a day will help reduce any stress and anxiety that can build up during the isolation time. Read this blog to get an idea on how to start: https://www.rhs.org.uk/advice/beginners-guide. You’re also able to leave the house to exercise once a day, so why not go for a light jog or brisk walk? As long as you keep your distance from others, a bit of time outside will help you mentally and make staying inside more bearable.