Just push it as hard as you can without risking injury for 20-30m, then quit. Do that with high scheduling variance (one week do it 4 times, the next week 1 time, etc. Variance, not routine, is key). Combine with long walks (to work if you're not too far away), bike riding, anything to reduce your sedentaryness.
This isn't a body-building or triathlete program, it's just a healthy one. Don't think of working out in terms of deterministic, 1:1, input=output. Rather think of it terms of signaling your body in ways that trigger certain gene expression that leads to a healthier metabolism.
Read this book more details:
http://www.amazon.com/The-New-Evolution-Diet-Paleolithic/dp/...
Reviews:
http://www.thedailybeast.com/articles/2011/01/04/new-evoluti...
http://www.marksdailyapple.com/the-new-evolution-diet/#axzz1...
Author's site: http://www.arthurdevany.com/
His assertion is that he current method of treating diabetes is based on classical mechanics, 1-in-1-out, etc., where you measure your blood sugar and try to manually maintain it at a certain level with sugar and insulin.
But ...
1) the human body is a complex, non-linear, dynamic system. It is based on and responds to signalling, genetic triggers, etc., and ...
2) you don't need to micromanage your body, it will take care of itself as long as you don't essentially poison it.
3) the old method presumes there is something wrong with your body, when in actuality, the problem is with the way your body reacts to 'modern' (post-agricultural) foods. Diabetes is a symptom of that, so cut those foods out, and diabetes goes away.
It may not apply to all types of diabetes, IANAE, but seriously, stop by a bookstore and spend 20m reading just the first chapter (maybe 2, can't recall exactly), and figure out if it's something worth looking into further.
1. http://www.amazon.com/The-New-Evolution-Diet-Paleolithic/dp/...