We're always being told what we should be doing a the gym: go faster, harder, slower; use a medicine ball; buy a band! But perhaps more important are the things we shouldn't do during a workout. In fact, when's the last time you paid close attention to your weight lifting form? Even the most savvy weight room warriors make mistakes, especially as they tire. So that you don't cheat yourself out of an optimal workout—or worse, bring your routine to a screaming halt—we asked experts to reveal the most commonly committed sins. Read on to see if you're guilty, and how to attain immediate (ab)solutions.
SIN : Rocking hips and pelvis while doing biceps curls
If you're moving your pelvis back and forth during biceps curls, you are using the momentum to help you thrust the dumbbell upward, rather than isolating the muscle and using it to lift the weight. "You clearly aren't getting an effective workout, and you can also throw out your lower back from the back and forth motion," warns Gary Hunter, Ph.D., professor of human studies and nutrition sciences at University of Alabama at Birmingham.
To make sure you perform the motion allowing only the biceps to contribute to moving the bar, Hunter says, "Try the exercise seated, with your legs spread, and rest your right elbow against the inside of your right leg. Then do the same on the left side." "Another option," suggests Declan Connolly, Ph.D., director of the Human Performance Laboratory at the University of Vermont where he lectures on exercise physiology and kinesiology, "is to use a preacher bench, or to stand up against a wall with your butt and back firm against the wall. You should have a 25-degree hip angle, with your legs straight."
SIN : Stopping short
"Not exercising through a full range of motion is a common mistake, especially when doing biceps curls," says Hunter. Many people stop the exercise before they've extended their arm all the way down. This means they are only strengthening the upper part of the biceps instead of fully developing the muscle."
Each exercise should be done in a slow, controlled manner through the complete range, with emphasis on the completely contracted position. Full-range of motion movements contract and strengthen the muscle you're working and stretch the opposing muscle (in the case of the biceps curl, the triceps). Note: Do not confuse full range of motion with hyperextension—when you use more than the full range of motion, which can cause joint injury. "Hang your arms by your side and relax them. This is your range of motion for the biceps curl," says Connolly. "Anything more and you're hyperextending." Unfortunately it's easy to go too far if you aren't careful. "You are in danger of hyperextension any time you use any type of free weight," says Connolly. "That's why it's so important that your movement is controlled, and you use the correct amount of weight."
SIN : Holding your breath during a lift
It's easy to forget to breathe but very important. "Lifting weights causes your blood pressure to increase temporarily; holding your breath makes it soar even more, and then suddenly drop," says Hunter. "Such a dramatic fluctuation in your blood pressure can make you pass out—or, if you have a heart condition, it could even cause a stroke," he warns.
"It's important to develop a breathing pattern while you're lifting," says Hunter. Some people inhale at the beginning of a repetition and expire at the end, others inhale on the upstroke and exhale on the down stroke. Hunter says that it doesn't matter which you do. "The point is to take a breath with each repetition to make sure you're not holding your breath."
SIN : Lifting hips off the bench when doing a bench press
When you lift your hips you change the angle of your shoulders as you lift the bar, so you are using only your lower pectoral muscles instead of the entire pectoral muscle. Your feet are also contributing to the movement, so you're not working as hard. More importantly, says Connolly, "This puts more of a strain on the lumbar spine. Any excessive flexion or extension of the vertebrae is dangerous, especially when combined with loading."
One simple way to prevent this, suggests Connolly, is to place your legs on the bench with your knees bent and your feet down. How does this stop you from making that arch? "If you are tempted to push with your feet, you'll find very quickly that you'll lose your balance and fall."
SIN : Being sloppy with heavy weights"
One thing I see that makes me cringe is people doing standing flyes for their traps and lats while standing with their upper body bent forward so it is perpendicular to their legs," says Connolly. "The back should never be loaded in the flexed or extended position." Why? Any time you do an exercise that requires you to maintain your balance, you are contracting a bevy of muscles in the lower back. Add weights to that and your lower back could be in for more stress than it can take.
"The bottom line," says Connolly "is that if you can do an exercise with your back supported then do so." Try doing flyes while lying on a narrow bench with your back supported. "For the most part, if you can support your back either by lying on your back or on your stomach while you perform these exercises, you will alleviate the stress on your back, and it will be much safer," says Connolly. "Or bend over and lean on one hand and exercise the other. If you insist on doing these exercises while standing up, make sure your knees are slightly bent."
SIN : Allowing elbows to go too far behind the back in a bench press or chest press
As discussed earlier, there is a fine line between a full range of motion and hyperextension. It's hard to know how far is too far. In the case of a bench press or chest press, the further you bring your elbows down, the more you increase your chances of injuring your shoulder.
"A general guideline if you're doing a bench press is to lower the weight onto your chest until your forearms are perpendicular to the floor," says Connolly. "This means that your elbows drop slightly below your chest—but this will not overstrain your shoulder because aligning the forearm helps you keep good form." And there's an added bonus: "This will also force you to widen your grip, helping with balance," says Connolly. Keep this form in mind when doing a chest press.
SIN : Straining the neck when doing crunches
Straining the neck is a wildly common mistake with crunches, because people place their hands behind their neck and then yank their arms to bring their head up rather than using their abs.
"Do not do the crunch with your hand behind your back," suggests Connolly. "Instead, cross your arms in front of your chest and hold your torso, neck and head in strict alignment. Your back will elevate to the lumbar spine region, which is exactly what you want." Lifting your torso (and not just your shoulders) off the floor will give you a lower abdomen workout as well. You can also vary this by adding oblique twists.
SIN : Skipping the warm-up
"If you are lifting significant weight and you don't warm up," says Hunter, "it will be harder for you lift because your muscles won't be ready. You will also increase your chance of injury."
"Do a general warm up before you start lifting, by using a cardio machine at a moderate level for at least four or five minutes," says Hunter. Then do a specific warm up for each of the exercises, starting with about 10 reps of 25% of the weight you intend to lift, and then moving to 50%, before you do your real workout. "So, for example, if you are going to do 10 200-pound squats, start by doing 10 squats using 50-pound weights, and then 10 more squats using 100 pound weights. And then go to your workout (three sets of 8 to 12 reps)," says Connolly.
SIN : Being wimpy with weights
If a weight is so heavy that you have to jerk, bounce or swing to get it to the top of the movement, it's too heavy. "But on the other hand," says Hunter, "if you can do 20 or 30 reps your resistance is to light and you are wasting your time. You're not getting enough resistance training to increase muscular endurance or muscle size."
"The setting should be chosen so that your muscle fatigues by the last repetition on the number you choose to do," says Connolly. "For example, if you do sets of 12 reps, the 11th and 12th rep should be a struggle, after which you need to rest 2-3 minutes before you can do another set of 12. This takes a little playing around to determine the initial weight," says Connolly. "When you are able to do 15 reps at that weight, it's time to increase the weight."