Walk onto any gym floor, and there’s a high possibility you may be instantly overwhelmed. To your right is a sea of weight machines that feel completely foreign. To the left? The weight rack is surrounded by dumbbell-lifting bros who would rather be forced to run eight miles at a six-minute pace than actually make eye contact with anyone in a 12-foot radius. So you opt for the weight machines, not knowing if there are any weight machines to avoid. This could be great news: especially since research shows that within a few days of beginning a strength-training plan you may already notice a rise in your resting metabolic rate. Plus, lifting weights builds muscle, helps increase bone density, and has the potential to boost your mood.

But here’s the thing: sit down at the wrong weight machine, and you could be totally wasting your time. And hey, your time is valuable, right? Here, personal trainer Jon Pearlman, co-founder of Mission Lean, tells us which machines you should skip (and what you should swap in instead).

Weight Machines to Avoid #1: Lat Pull-Down

Targeting: Lats, biceps, infraspinatus, traps, pecs

Pearlman says: “Generally, if you are able to perform a bodyweight move instead of using a weight machine, you should. Working with your body weight will strengthen your body proportionally, not to mention assist you in training functionally for optimal muscle development and strength gains.”

Swap it for: The pull-up bar. Whether they’re assisted, jumping, or strict, traditional pull-ups are a easy swap. Add in some extra burn for your upper back by opting for a wide grip on the bar. (Here's how to get strict pull-ups.)

Weight Machines to Avoid #2: Hamstring Curl

Targeting: Hamstrings

Pearlman says: “You definitely don’t need weights to get great burn in your hamstrings.”

Swap it for: A Swiss ball. Perform a stability ball hamstring curl, which tones your glutes at the same time.

Weight Machines to Avoid #3: Leg Extension

Targeting: Quads

Pearlman says: “There are a lot of alternatives that can help you get a full leg workout, and not just targeting your quadriceps.”

Swap it for: Squat jumps. Not only do they pack a cardio wallop, raising your heart rate right away, but they also hit the leg as a whole. Aim for five sets of 30 seconds followed by a 30-second rest. If you find that you’re handling this with ease, cut your rest periods in half.

Weight Machines to Avoid #4: Bench Press

Targeting: Pectoralis major, anterior and lateral deltoids, and triceps

Pearlman says: “Ditching the barbell could help you build a functional, lean physique instead of bulky muscle.”

Swap it for: Push-ups. “Focus on upping the pace of your push-ups so your heart starts pumping and you work up a sweat,” he says. “You’ll be toning your chest, arms, and back muscles, and you’ll be getting in a cardio workout too if you’re able to crank them out at a swift pace.”

If getting in shape fast is your goal, use this Get Fit Fast guide to get you there.