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5 Common Strength-Training Mistakes

3 Ways to Boost Your Strength-Training Smarts

  1. Exercise Library – American Council on Exercise
  2. Growing Stronger – Strength Training for Older Adults – Centers for Disease Control and Prevention
  3. Weight Training: Improve Your Muscular Fitness – Mayo Clinic

by Beth Shepard, M.S., ACE-CPT, ACSM-RCEP, Wellcoaches Certified Wellness Coach

Strength-training is an important element of a well-rounded fitness program, but unless you’ve been properly trained in form and technique, it’s easy to get it wrong. Performing strength exercises correctly makes each workout more efficient, effective and safe. Avoiding these frequently-seen exercise errors will help you achieve your goals and reduce your risk of injury.

1. Speeding through your workout.

Strength exercises are a lot easier when you go fast because momentum is doing a big chunk of the work. To get the most out of each lift, aim for an even level of force throughout the movement. Think slow and controlled — the standard 2-3 second lift (concentric, or muscle-shortening, movement) and 3-4-second release (eccentric, or muscle-lengthening movement) works well for most people. The recommended rest interval in between sets varies with the training goal and workload: from 30-90 seconds for general fitness, to 2-5 minutes for muscular strength and power. With adequate recovery time between sets, you’ll replenish the muscle energy stores needed to put forth your best effort.

2. Doing traditional sit-ups or other spinal-flexion movements.

You’ve seen them — fitness enthusiasts who proudly crank out hundreds of crunches during a single workout in pursuit of a six-pack. Unfortunately, they’re setting themselves up for serious pain and injury. According to Stuart McGill, Ph.D., a spine health expert and researcher, these exercises place a tremendous amount of stress on the intervertebral discs, boosting risk of pain and herniation. He recommends a modified curl-up:

  • One leg bent and one leg extended, hands beneath the lumbar region. Unload the head and shoulders to challenge the abdominal muscles without spinal motion. Hold for 1-2 breaths and return.
  • For more challenge, raise head and shoulders slightly off the floor with limited upper-back movement without moving the neck or low back. Hold for 1-2 breaths and return.

Hundreds of repetitions aren’t necessary or recommended, even with the modified curl-up. Aim for 8-12 to start, and adjust according to your strength and endurance needs. Use the extra time to perform additional spine-stabilizing core exercises, such as side planks, cat-camel and bird-dog, for a more balanced workout.

3. Not moving through a complete range of motion.

Attempting a lift that’s too heavy reduces range of motion. For optimal strength gains, decrease the weight until you can move it through a complete range of motion for a minimum of 1 set of 8-12 repetitions. When you can perform your goal number of sets and repetitions in proper form, increase your workload by approximately 5%.

4. Overemphasis on deltoid exercises while ignoring rotator cuff muscles.

Fitness enthusiasts often aim for the visual appeal of buffed-up deltoids at the expense of the rotator cuff muscles (supraspinatus, infraspinatus, teres minor and subscapularis), but this can lead to shoulder instability and injury. Exercises such as internal and external rotation with resistance tubing, supine rotator cuff and stability ball push-up, help strengthen and stabilize the rotator cuff.

5. Picking a workout and sticking with it.

If you haven’t mixed up your fitness routine for months — or even years — chances are good that you’ve reached a fitness plateau, and may have some strength imbalances. Challenging your muscles with progressively heavier loads is essential for building strength. But even if your goal is to maintain your muscle fitness instead of improving it, adding variety can help. Keep your muscles guessing by trying new exercises that target the major muscle groups. If you always use weight machines, for example, integrating dumbbells and barbells into your regimen will add a new level of challenge. Enlist the help of a certified fitness professional as needed to ensure proper form, technique and workload.


  1. McGill S, Low Back Disorders: Evidence-Based Prevention and Rehabilitation, Human Kinetics, 2007
  2. Baechle T and Earle R, editors, Essentials of Strength Training and Conditioning, 3rd Edition, National Strength and Conditioning Association, Human Kinetics, 2008
  3. Bryant C and Green D, editors, ACE Personal Trainer Manual, 4th Edition, American Council on Exercise, 2010
  4. Bryant C and Green D, editors, ACE’s Essentials of Exercise Science for Fitness Professionals, American Council on Exercise, 2010