7 minutes is better than nothing, but you really need 30 minutes minimum to get your metabolism up to the point where it stays elevated throughout the day. Less than that, and you don't get the lasting, day long benefits of a workout.
The concept of "you don't need a gym membership or weights to get results" is very sound. My girlfriend is essentially a full-time acrobat (extremely fit, trains for 25+ hours a week), and she started me on a simple workout that takes 30-60 minutes, and goes in five week cycles of building up in reps. It's produce more results in a shorter period of time than any traditional gym workout.
The concept of "you don't need a gym membership or weights to get results" is very sound. My girlfriend is essentially a full-time acrobat (extremely fit, trains for 25+ hours a week), and she started me on a simple workout that takes 30-60 minutes, and goes in five week cycles of building up in reps. It's produce more results in a shorter period of time than any traditional gym workout.