The effects of too much sitting are hard to counter with exercise. Even if you work out 7 hours a week -- far more than the suggested 2-3 hours -- you can’t reverse the effects of sitting 7 hours at a time.
If you exercise every day, that’s good, but it won’t make a huge dent in extra weight you gain as a result of too much screen time
Don’t throw away all that hard work at the gym by hitting the couch for the rest of the day. Keep moving!