It is. It's brutal, but yields great strength if you take it to the limit.
Once you see how tough 1 pushup is to do at these slower speeds, and apply it to other exercises you WILL get Tonken-Ripped lole!
Do this with pull-ups and multi-directional crunches too and your body will be like diamond fren :)
Remember though; rest is as important as activity when building strength or skill. So don't forgetti to take time to unwind and stretch too..Your fortune: Good news will come to you by mail