Essentially, you'll use an ordinary garage magnet (available on Amazon) and attach it to your wrist.

Then pick up a dumbbell and let the magnet contact the steel frame of a rack or other steel post.

Now you'll do what is essentially a Bayesian Curl (those are normally done with a cable from behind your body to get the stretch).

Once the magnet is attached, use a strong bicep contraction to develop enough tension to free the magnet from the steel.

** DO NOT use momentum or sudden movements to "pop" the magnet off.

You want to gradually develop tension by contracting the bicep HARD.

This working against an immoveable object is generally what's known as an overcoming isometric - you're trying to overcome the immoveable object.

Here, though, once you develop enough tension, the magnet will come free and you'll continue the curl up powerfully.

I found this one gave me excellent bicep activation and an intense stretch at the start of every rep.

Get the full rundown on it here...

Watch it on YouTube