Bodyweight workouts and 'time under tension'

upgetupgetup

Anyone have experience with really exploiting these?

I'm staying away from weights for a while (please don't hassle me, will go back when I know what's up with my body), and am looking at ways to increase intensity, while not going over 15 reps.

Any estimations on roughly how much additional stress eg a quad gets with time? For eg a 3 second descent into a single leg squat, hold at lowest point for 3 seconds, and 3 s back up? Or, same length of time held at midpoints of the movements?

As advised by Alwyn Cosgrove in "Your Body is a Barbell":
http://articles.elitefts.com/training-articles/your-body-is-a-barbell-no-dumbbells-no-barbells-no-problem/