Quote Originally Posted by Mike T View Post
I found this:

"To increase strength and power, the best rest period is 2-5 minutes between sets. To increase hypertrophy (muscle growth), the best rest period is 30-90 seconds between sets. To increase muscular endurance, the best rest period is 30 seconds or less between sets."

Whether it is true or not is another matter. But doing the exercise to failure is probably the most important thing.
Cheers Mike - that's helpful.

Re your other post, I also have to rest my abs and pelvis on the ground simultaneously, as mechanically I found it too difficult to touch just my chest down meaningfully.