Strength training is a great way to stay in shape and even recommended by most health care professionals as the perfect weight loss method, but newcomers and experienced gym rats alike should practice safety when working out.

According to the American Council on Exercise, the 10 most common mistakes made by gym-goers that often lead to strains or significant injuries include: all-or-nothing approach, unbalanced strength-training programs, bad form, not progressing wisely, not enough variety, not adjusting machines to one’s body size, focusing on anything but your workout, not properly cooling down after your workout, poor gym etiquette, and not setting realistic goals. Our risk for injury at the gym is also highly dependent on the type of exercises we’re performing. Here are five exercises we should avoid at all costs:

1. Crunches

Abdominal crunches are often what pops into the mind of anyone looking for six-pack abs, but in reality they can be downright dangerous. While crunches may seem like a simple exercise movement, that spinal flexion, rounding your lower back so you can bend at the waist, pushes discs back toward your spinal cord and often leads to a herniated disc in the lower back. There are a number of effective ab exercises that don’t put you at risk to injury.

2. Upright Rows

While performing upright rows, you may notice that your shoulders are rotating inward (internal rotation) but also elevating. You may not realize the stress you’re putting on your rotator cuff that can eventually lead to injury. Two million people in the United States saw their doctors as the result of a problem with their rotator cuff in 2008, the American Academy of Orthopedic Surgeons reported. Another common injury that can occur through lifting your arms while they're in an internal rotation position is known as shoulder impingement syndrome, which can result in difficulty reaching upward or pain when arms are extended above the head.

3. Leg Extension Machine

Seated leg extension machines require a resistance point that is placed by the ankles. This placement can put a lot of stress on the knees in the form of ACL tension. The heavier the weight, the more likely you are to suffer a knee injury. Instead of an isolation exercise like leg extensions, consider a compound exercise like squats. Not only are squats thought to be the pinnacle of lower body strength, but they also provide a great core workout and aid in weight loss. Just be sure you practice the correct form, as with any exercise.

4. Smith Machine

When supplementing squats for leg extensions, make sure they are not being performed on a Smith Machine. Although the Smith Machine was designed to limit injury by providing barbell support via built-in bar guides, theses guides are often what leads to injury. Since the barbell is locked into a straight up and down motion, that’s the only way your body can move. This motion, which our bodies are not meant to go in without going backward puts added stress on the knees and lower back. Ditch the Smith Machine and go straight for traditional barbell squats or dumbbell squats to maximize muscle gains and prevent injury.

5. Behind the Head Lat Pulldowns

People often think that adding a little variation to their lat pulldown by pulling the bar down to the back of their neck will help build upper back strength. They tend to neglect the stress they're putting on their shoulders by bending them in a way they were not meant to: backward. Performing the motion that is required to complete behind the head lat pulldowns, especially with a lot of weight, can quickly lead to a rotator cuff injury.

When performing lat pulldowns, bring the bar down in front of your head to around the collarbone area while squeezing your shoulder blades in to meet each other.