Having space in your house can help to stay active or having garden space but stretches can be done anyway, I personally enjoy doing lunges and press ups but star jumps are a good way to stay fit and healthy bye doing 2 round of 30 you can break a sweat in a short amount of time. If your focusing more on core strength or upper body I would suggest pull ups an easy warm up that puts work on the core I would suggest 2 rounds of 20 but it really depends on your fitness levels for upper body I would suggest pull ups if you have the facilities to be able to do this, I would recommend 2 rounds of 5. Thanks for reading I will post 1 every 3 days