The Smith machine and the BOSU ball are horrible. One's a squat rack with training wheels. The other is a useless, pneumatic pimple on the face of the gym floor, just begging for me to lance it with a pocket knife.

So maybe you can imagine my revulsion when I saw Brianna Alexander, a Bret Contreras butt protege (shown in the video), using both of them to work her abs. She was lying flat on her back on top of the BOSU and gripping the Smith machine bar like she was going to do a weird, hyper-extended bench press, only she was using it to do partial-range ab contractions.

Smith Machine BOSU Ab Crunches

Granted, the Smith machine in the video is one of the new-fangled ones that lets you move in two planes of motion – up and down and back and forth – but this movement works equally well in a conventional Smith machine.

Intrigued, I waited for her to finish and move on to another area of the gym so I could try it out. I also didn't want anyone to see me using these two stupid pieces of equipment.

Like a Bad Bowl of Chili

Surprisingly, it felt... good. The movement targeted the rectus abdominis perfectly. I pushed out 10 reps, with no additional weight on the bar, stood up, and then doubled over in pain. I felt like I'd been punched. That, or eaten a really bad bowl of chili from a street vendor's hygiene-challenged cart. That's how bad the cramps were.

No ab exercise had ever hit me like that. I was in love, in love with the BOSU ball and the Smith machine. Can a Hallmark unconventional-love story movie be far behind?

How to Do It

The movement, which I've coined "Smith machine BOSU ab crunches," is a lot like the movement T Nation contributor John Rusin described here: Partial Pulses. While you may or may not cramp up, this is a five-star ab exercise. Just remember the following points:

  • Position the small of your back over the center of the BOSU ball and "wrap" your spine around it.
  • Grab the bar with your arms perpendicular to the ground. Keep your elbows locked.
  • Start the movement by "curling the spine" upwards as far as your range of motion will allow.
  • Make sure not to protract your shoulders as you curl up in an effort to raise the bar higher (remember, it's an ab movement, not a chest or shoulder movement).
  • Reverse the movement until you're flat on the BOSU. Pause a second before starting the next rep.

Do a number of reps that's concurrent with your current ab training. Try it first without any additional weight, and then load up as necessary.

Related:  Big, Thick, Chunky Ab Training

Related:  8 Inconvenient Truths About Ab Training