You don't have to spend a lot of money to get a good workout. In fact, depending on what you keep in your garage, you may not have to spend anything.

Last week, I experienced firsthand the power of "Battling Ropes," an activity that's as simple in concept as it is challenging in execution. All it requires is some rope, yet it's easily the hardest exercise I've tried so far.

No wonder our seafaring forebears had such huge arms. They were probably battling ropes centuries before North Carolina strength trainer John Brookfield codified "Battling Ropes" into a formal routine and started selling DVDs.

Here's how it works, as drilled into my biceps by David Morgan, a local fitness instructor and former high school wrestling coach:

Start with a length of rope. Depending on space and how hard you want to work, it can measure anywhere from 50 to 100 feet long. It can also vary in weight and width. Novices should start with 1.5-inch polyester and work up to larger sizes of heavier manila.

Next, wrap the rope around a pole or anything stationary, such as a tree, pipe or dumbbell. Your grip can be either overhand or underhand. Whatever's most comfortable.

After that, all you do is snap the ropes repeatedly, creating waves strong enough to hit the pole. Try to continue for at least two minutes.

Style does count, at least to the person doing it. The variations are virtually endless, and each one taxes slightly different muscles.

You can use both hands or just one, creating vertical figure-eight patterns or snake-like loops on the ground. You can whip the ropes simultaneously, independently or all the way over your head in large arcs. Any of these will be hard to keep up.

Ideally, the waves should be smooth and symmetrical. But even that doesn't really matter, because it's all part of an intense, hybrid workout combining both cardiovascular and strength-building exercise.

Should you get bored, throw yourself a serious curve by altering your stance. Sit down, kneel, move closer to the pole, or stair-step at the same time, or raise and hold the rope's focus point.

Hardest of all, I think, is a separate activity that involves pulling instead of whipping, favoring arm strength over cardiovascular endurance. Here, it's best to have 100 feet of heavy, manila rope, the kind that creates friction rubbing against itself.

Wrap one end all the way around the pole and then pull the entire length as fast as you can, grabbing the rope between your legs. When you're finished, wrap the rope in the opposite direction and pull it all again.

Repeat until exhaustion, or, if you're a machine, until you've pulled 52 lengths, an entire mile. Complicate the process by turning around and pulling through your legs, or by kneeling and lugging the rope over your shoulder, like a fireman distributing hose.

Morgan pushed me to pull 600 feet this way, a distance that left my arms feeling like putty. And he was just getting started, eager to demonstrate several more devilish workout designs.

Driving home, I forgot my sore triceps for a moment and pondered the beauty of this routine.

Here's what I concluded. Elegant but complicated, easy but difficult, "Battling Ropes" is that rare activity that costs nothing if you have rope and can be done almost anywhere. Like all the best things in life, it's free, but to fully enjoy it, you still have to work really, really hard.