If you don't know your way around a weight room, heading to the gym can be intimidating -- and even dangerous . But paying attention to a few simple rules of proper technique can make you slimmer, stronger and healthier all over.

We spent an afternoon at Equinox with trainer and manager Rebecca Woll, learning the ins and outs of some of the most popular strength-training machines.

In the coming weeks, we'll be sharing Woll's thoughts on the biggest mistakes we all make while building muscle, plus her tips and tricks for better form. This week, we're focusing on abs.

The Faux Pas: Woll says she sees far too many people hop on this machine, the torso rotation, and the biggest problem, especially for women, is that it's just too big for our bodies. But it's also rough on your back . Rotating the spine while keeping the hips in alignment with the machine goes against her number-one rule on most other machines: the back must be flat against the bench .

The Fix: Ditch this machine from your routine altogether, and instead, try a fairly new concept growing in popularity called anti-rotation . "Core muscles are for stability, so we want to strengthen those [without] any type of rotating that's not good for the spine," says Woll. All you have to do is grab the handle of a cable machine, pull it into your chest, then hold it out in front of you.

Make sure feet are hip-width apart, and tilt your hips slightly forward so your glutes are squeezing. From there, you can either bring your hands back to your chest and call that one rep (do 10 total) or simply hold the position. It may sound easy, but think of it like a standing plank . "A lot of times it's hard for people to feel their core engaging in a plank," says Woll. "This is a good way to start to get those core muscles firing. Do a plank after this and you'll understand how it works." In a plank, you're also supporting all of your body weight, she says -- Woll only put five pounds on this cable.

Tell us how it goes in the comments below, and be sure to check back over the following weeks to fix your form on the row machine, the seated fly and more.

Check out more in our Fix Your Form series below:

Photos by Damon Dahlen, AOL

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