I have a bit of a problem

So, I need to exercise more (as I am overweight, and it makes me really self cautious) but I'm too afraid of people seeing me, if that makes sense. I'm a teenager. I live in the top floor in an apartment and I can't jump around because that makes noises for the person downstairs, and I'm too afraid of people seeing me outside exercising. I don't know why, I'm just freaking out at the thought of people watching me running around outside. That actually prevents me from doing a lot of things, being afraid of judgement.