Hip Abductor/Adductor Machine

Put simply, "The hip abductor/adductor machine is probably the most useless in the gym. You are targeting one very specific area whereas you can engage multiple lower-body areas at once more effectively in other exercises and pieces of equipment," says Rebecca Gahan, CPT, owner and founder of Kick@55 Fitness in Chicago [3].

"Specifically, weighted step-ups and lunges will help to reduce fat in this region, expend more calories, and lean out the glutes, quads, and hamstrings," she says. Go for a medium, heavy dumbbell that really works your legs and challenges you.

Side Bends

"Dumbbell-loaded side bends are worthless. People think you can spot reduce fat, but it doesn't really work that way," says Gahan. Here's why: "You are breaking down muscle, then building up later by ingesting protein, but there isn't enough resistance in this exercise to effectively challenge the muscle, so the net effect is zero," she says. "If you want to impact your side torso, obliques, and lower-back region, try oblique push-ups, instead," she says. Here, you rotate your leg underneath you as you push down toward the floor.

Leg Extensions

"Leg extensions are ineffective and dangerous. The goal is to create definition in the quad region, but instead there is a singular focus on the area right above the knee," says Gahan. Here, you sit on the padded machine and extend your legs up and outward. The amount of force in this area can ultimately cause knee pain. "A better alternative is a barbell front-loaded squat. You are working the entire anterior lower-body region instead of one small area, and the risk of injury is far less," she says. A barbell front-loaded squat places the barbell on the front of your shoulders, not on the back, as you sit.

Triceps Kickbacks

"Most people use weights that are too heavy for this exercise, which leads to poor form, making it basically ineffective. The goal is to work the muscles in the back of the arm, but the wrong weight can make it almost impossible to fully engage these muscles and can cause strain on your shoulder and elbow joints," says Katie Dunlop [4], trainer and founder of Love Sweat Fitness [5], to POPSUGAR.

"When done right, this can be effective, but you have to keep your weight light so you can keep your elbow high and fully straighten your arm at the high point of the exercise," she says. An even better option would be a triceps dips, though. "It's a simple bodyweight exercise, but with the right form can be SUPEReffective, even more so than using weights," she says.

Sit-Ups

"In my opinion, they're a total waste of time," says Dunlop. "They only target a very small portion of your abs and can be tough on your neck and shoulders, especially if you don't quite have the strength to fully use your core to get up. A better option would be a plank or double leg lift, which both engage almost your entire abdominal wall and specifically target your lower abs, which is most people's problem area," she explains. To do a double leg lift, lay down on a mat and lift your legs straight up in the air, pulsing upwards.

Curtsy Lunge

A curtsy lunge, where you lunge back sideways, forming a diamond shape with your legs, isn't effective. "These are cute and extremely popular, but they break the major rule of biomechanics by not encouraging proper movement mechanics and can potentially place extreme stress on the hip socket, the IT band, and TFL [a thigh muscle]," says Marlon Bascombe [6], personal trainer and run coach at Complete Fitness in New York, to POPSUGAR. Instead, stick with the simple forward or reverse lunge. There are many ways to use these two, focusing on the isometric holds in the middle, he says.