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6 Common Strength-Training Mistakes to Avoid

Aug 29 2021
7 min read
woman holding loaded barbell in front rack position

Whether you’re just beginning to add strength training to your routine or you already do upper- and lower-body muscle-strengthening moves...

...knowing—and avoiding—common pitfalls is key in ensuring you get the most out of your workout and protect yourself from injury. Taking some time to work with a pro is a great way to get a handle on the dos and don’ts of strength conditioning, especially if you’re just getting started or want to try new or more challenging movements. If you’re exercising on your own, though, it’s even more important to make sure you’re not sacrificing good form, choosing inappropriate weights or spending too little time on each exercise. Here’s what you need to know about these and other common strength-training mistakes:

Adopting Incorrect Form

Learning and maintaining proper form when doing strength exercises is essential. Why? Because without it you won’t fully benefit from each move and because good form is your best defense against getting hurt.

Lifting weights, using machines or other equipment or even performing bodyweight strength moves incorrectly usually results from two causes: trying exercises on your own without instruction or rushing through your workout (see below for more on that). Meeting with a trainer—even for a single session—can give you the basics on proper form and increase your confidence. Every exercise calls for a certain position, of course, but here are some general tips to follow when it comes to form:

  • When standing, focus on your body’s alignment: Head should be over shoulders, shoulders over hips, hips over feet; gaze is straight ahead (looking down rounds your shoulders and collapses your chest).
    Keep your shoulders down and chest lifted.

  • Engage or “brace” your abdominals without holding your breath.

  • Keep your knees slightly bent, not locked (unless otherwise specified).

  • Maintain proper back posture according to what the exercise requires (such as a neutral spine, pelvic tilt or arched back).

  • If you’re unsure about your form, ask a trainer for guidance before doing any exercise.

Using Incorrect Weight

While lifting weights should challenge your muscles, having to use your whole body to hoist them up is a sign they’re too heavy and can strain your knees, back and shoulders. A cumbersome load also reduces your range of motion, preventing you from fully extending or contracting during each repetition; this means you’re only strengthening part of the muscle. Too-heavy weight won’t necessarily cause harm, but it will shortchange your workout. A safe and effective range for most exercisers is being able to do two or three sets of eight to 12 reps of an exercise with proper form, to muscle fatigue. (The exception would be someone who has been exercising for a while and wants to build overall strength, in which case the number of reps can be reduced.)

Performing Sit-Ups

When it comes to abdominal and core strength work you may have done traditional sit-ups back in gym class, but now experts say this exercise places too much stress on your spine’s intervertebral discs (the little cushions that sit in between your vertebrae), boosting risks for pain and herniation. Instead, modified curls or crunches are safer movements that still produce results. Try a Basic Crunch or Bicycle Crunch (explained in our bodyweight strength training article) or other core-strengthening exercises (see our No-Equipment Ab Workout piece).

Ignoring Muscle Groups

Sometimes we’re so focused on toning a specific body part that we neglect others. This can lead to injury (since the muscles you’re ignoring may be weak) as well as overuse injuries of the muscles you are working. Remember to include multiple muscle groups in your strength-training workout; keeping a log of what you do during each session is the simplest way to track what you’ve done and easily mix up your movements. Some of the most commonly neglected and vulnerable body parts are the smaller rotator cuff muscles, which surround your shoulder joint. Try incorporating this rotator cuff strengthener into your upper-body routine:

Secure one end of a resistance band to a doorknob or another sturdy object at waist height. Stand a couple feet from the door with your right side facing the doorknob, feet hip-width apart. Hold the loose end of the band with your right hand (your left arm hanging by your side) and bend your right elbow. Bring your right forearm across your body, pulling the band, keeping your right elbow pressed into your side.

Return to start. Perform 10 to 12 reps, then switch sides.

Rushing Through Your Workout

Even though it feels easier to power through strength exercises at a faster pace, it’s important to go slowly and use control to truly challenge your muscles and to keep proper form. Aim to spend two to three seconds when lifting (what’s called the concentric contraction of the muscle) and three to four seconds when coming out of the movement (called eccentric contraction). For example, when doing a bicep curl, take two or three seconds to lift the weight toward your body and three to four seconds to lower it slowly down. By taking more time to lower the weight, your muscles generate more force and, in turn, gain more strength. How long you rest between sets depends on how many reps you do, but if you’re doing about 10 reps, you can take one to two minutes to rest between sets; taking some time to recover will help you maintain good form and have enough energy for the remainder of your workout.

Skipping Your Stretch Session

After a workout your muscles are tense, making them more prone to injury. Be sure to choose stretches that isolate the muscles you just focused on. For example, if you did squats and lunges, spend some time stretching your quads, glutes and hamstrings (try these cool-down stretches). Hold each stretch for up to 30 seconds (no bouncing!), and then return to the starting position and relax for a few moments. Ease into the extension again, elongating the muscle a bit further for a deeper stretch, if you’re able. A foam roller can be a beneficial tool, too:

Sitting on the ground, place the roller under your glutes, hamstrings, calves or other areas, and roll your body over the roller along tense or sore spots to help loosen them up.