Building off the medicine ball I made in a previous instructable, I've made a tornado ball for use with sledgehammer style slams.

This tornado ball is designed almost specifically not to rebound, so it isn't good for any sort of fast repetition training, but it's phenomenal for swinging over your head by the rope like a sledgehammer. And this, despite seeming pretty basic, is a great workout.

Step 1: Materials:

One 55 yard roll of "professional duck tape" duct tape, $4 at walmart.

6 feet of thick rope, I used some rope I had laying around, aka free.

Two spalding heavy duty cloth basketball nets, $3 each from walmart.

One thin yoga mat that I had bought online for another project, less than $10, though I don't remember the exact price. Got it off amazon though.

And a warning: This Instructable is going to be pretty picture heavy, because I took pictures at every little step. So pay attention to the pictures to replicate my results!

Step 2: Putting It All Together

Lots and lots of pictures:

This is the beginning of wrapping the original medicine ball from my other instructable with a yoga mat, to make it a little softer upon impact with the cement.

I eyeballed a square of yoga mat, got my pocket knife and my duct tape handy, and went to work.

Step 3: Adding the Basketball Nets

Lots more pictures:

Adding the nets around the medicine ball to make a harness for it.
Doubled up and used two nets because I didn't trust one net to hold the weight of a 25 lb medicine ball colliding with the ground at high speeds.