5 Exercises You Should Never Do

Most people believe that all exercises are good, safe and effective. After all, it's exercise—and that has to count for something, doesn't it?

The truth is that some common exercises aren't safe at all (especially for people who have muscle, joint, and health problems). Certain exercises require a bit more know-how than the average person possesses. And other exercises are downright wastes of your time.

But before we examine some of the most controversial exercises, I want to make it clear that every exercise on this list isn't always unsafe or ineffective for everyone. What you should do—or avoid—depends on your goals, fitness level, health history, workout schedule and other personal issues. An article like this can't replace your own efforts to identify your goals and needs. That requires you to do some research on your own, talk to your medical professional about any pain or physical limitations you have, and learn how to exercise with proper form and technique.

So what makes an exercise risky? Here are a few red flags to look out for:

Any unusual or "unnatural" movement pattern in the exercise
Any movement that causes pain or discomfort in any way
Any movement that enhances muscular imbalances that are already present
Any movement that requires joint flexibility that is above and beyond your range of motion
Any exercise with risks of injury that outweigh the potential benefit of the exercise itself

That said, the following exercises pose high risks and are generally considered controversial by reputable fitness organizations and experts.

1. Behind-the-Head Lat Pull-Downs

In the old days, people were actually taught to pull the bar behind their heads when doing a lat pull-down exercise--and many people still do that today. Bad idea.

The problem? Pulling the bar behind the neck puts far too much stress on the shoulder joint, explains Michele Olson, PhD, an ACSM fellow and NSCA-certified strength and conditioning specialist.

"The amount of outward rotation on the humerus combined with pulling it downward has a very un-stabilizing effect on the shoulder joint. The top of the humerus is actually pushing outward and away from the joint, overstretching the tendons and ligaments on the front of the shoulder," she explains, which can lead to injury. In addition, almost anyone who spends their days desk-bound is likely to have rounded shoulders or poor posture—a symptom of poor shoulder flexibility (among other things). Pulling the bar behind your neck only accentuates this misalignment, making this exercise a no-no.

The Alternative: You can still work your lats without the risk of behind-the-head pull-downs by pulling the bar down in front of you. Sit with your spine straight, abs pulled in, and then lean your torso back slightly, keeping your spine straight. Pull the bar down towards your chest, but not below your collar bone.<pagebreak>

2. Hovering Leg Lifts

Boot camps, yoga classes and sometimes even your old P.E. teacher probably led you to do this common move: Lie on your back (with your head and shoulders either down on the ground or "crunched" up) and lift your straight legs right off the ground to hover just a few inches from the floor in order to work your abs.

The problem? Sure, this engages your abs, but lifting your extended legs straight off the ground "puts an incredible amount of stress on the lower back and can lead to injury," warns Tom Holland, M.S., CSCS, and exercise physiologist and author of "Beat the Gym". "The cost-benefit of this move is simply too high," he says. "And there are numerous better ways to work the abdominals without the risk."

The Alternatives: Work your abs without straining your lower back by starting with your legs up in the air (not lifting them from the ground) in line with the hips. Then lower your straight legs down to about a 45-degree angle—or only as far as you can lower the legs without feeling any strain in the back and without changing the position of your back (don't arch or flatten). You can make this movement even safer if you have back issues by doing it with bent knees. Or work your abs by doing standard bicycle crunches or plank exercises.

3. Seated Knee Extensions

This is a very popular exercise machine for targeting the muscles on the front of your thighs (quadriceps).

The Problem? This exercise poses major risks to the knees when the weight is heavy and when the knees are fully extended. Lifting heavy weights in this position (with all the resistance focused at your ankles) is not what the knee was designed to do. If you have any kind of knee problem, or use a too much resistance during this exercise, you can easily run into big trouble. Here's why: Fully straightening the knees against this type of resistance "puts an extreme amount of shear stress on the knee joint, which can strain the tendons and overly compress the knee's cartilage," says Olson.

The Alternatives: Simple squats and lunges (known as closed-chain exercises) with or without added weight, will work your thigh muscles naturally, safely and effectively. If you want to expand on these exercises to develop explosive force for sports like soccer, basketball or volleyball, try sport-specific plyometrics. If you can’t do lunges and squats because you lack the leg strength, start with simple ball squats or modified "mini" lunges, and only lower yourself part way, gradually increasing your range of motion as you get stronger.

Olson also suggests that you can modify this exercise to make it safer. Simply lift the weight (extend the knees) just halfway versus all the way up to straight legs. This also gives the quads some direct isolation work while minimizing knee stress. She also suggests lifting a weight that isn't too heavy—you should be able to do about 18 reps of this exercise. If you can't do that many, the weight is too heavy to be safe.

4. Inner and Outer Thigh Machine Exercises

These machines are pretty popular in most gyms. Both involve sitting with your knees bent in front of you, with the adduction machine is designed to target the muscles of the inner thighs and the abduction machine helps target the outer thigh muscles.

The Problem? Using your inner and outer thighs to lift weight while in a seated position puts you at risk of straining these relatively small muscles and aggravating lower back and hip problems. In addition, your inner and outer thigh muscles are designed to support movement, not to be prime movers like they are in these types of exercises.

The Alternatives: The best way to target these muscles safely is with body weight exercises, such as standing adduction, standing abduction, lying adduction and abduction exercises, Pilates exercises or similar movements that use resistance bands or the cable-cross machines. Always start with a weight you know you can handle, and add resistance gradually.

5. Upright Rows

In this exercise, you stand holding a barbell or two dumbbells, with hands close together and arms extended. From this position, the weight is brought up toward the chest as elbows splay out for one rep.

The Problem? Upright rows are controversial because they cause the upper-arm bone (humerus) to bang up against the AC (acromion process) joint, according to Olson, which can compress the nerves in the shoulder area and damage the cartilage in the AC joint, which can lead to arthritis.

The Alternatives: The purpose of this exercise is to work the shoulders (deltoids) and upper traps. So instead of standing to perform an upright row, try bent-over rows by bending forward 90 degrees at the hip, holding the weight down beneath your shoulders with hands slightly more than shoulder width apart, then lift weight straight up towards your chest until elbows and shoulders form a straight line. You can also try front or lateral shoulder raises, using a modest weight, so that you don’t need to lean back or use momentum for assistance.