You could look at working remotely. You could still stay in tech but also live a healthy lifestyle.
If your work is busting your ass so hard you feel it's literally impossible to move at any point during the day, get a new job. That's not SV as a whole.
As an individual, on the other hand, leaving the industry until they get their act together could be the best course if your circumstances allow it. Altering your own work practices and lobbying your company to pay more attention to these issues are also worth considering.
I don't think a treadmill as a desk is a great solution.