It's probably not a difficult question when I put it like that: would you rather watch 3.3 episodes of tv or be healthy?
NHS recommends adults to be active every day. 150 minutes activity per week is needed to maintain a healthy lifestyle. It isn't much at all - 1.5% of your whole week! That's watching 3.3 tv episodes (that are 45 min each). Who wouldn't skip that to get a healthier, happier and longer life? Click here to read about all the positive benefits you get from exercising.