The worst advice we've ever heard about weight lifting

Something about weight lifting makes everyone feel like an expert. And that leads to some pretty bad advice. That bad advice could discourage you from vital strength training or compromise the effectiveness of your workout. So it's important to know the truth and maybe set a few people straight. Here's the worst advice we've ever heard about weight training:

Only use free weights

Free weights have several advantages over exercise machines. They're versatile and can be used with a wider range of motions. They require coordination and make muscles work together to stabilize their path. They can be moved around the gym. But that doesn't make strength-training machines worthless. If you're new to strength training, machines are a great way to get started. By limiting the range of motion, they take some of the guesswork out of how you're supposed to move. Weight machines also make it easier to exercise by yourself. Instead of moving heavy weights around or worrying about finding a spotter to help you, you can just start working out. Changing the resistance is as easy as moving a peg or twisting a dial. And weight machines can isolate a specific muscle, which is great if you've been injured or have chronic pain. For instance, squats might be painful for someone with a bad back, but she could still exercise her legs using a machine that works her legs without working her back.

Avoid weights if you want to stay slim

Many people associate weight lifting with bulking up. But the truth is weight training is far more likely to slim you down. Lifting weights burns calories, especially when you're using large muscle groups such as the legs, core and back. It also boosts your metabolism, which leads to even more calories burned. Muscle is a lean tissue, so it adds a lot less girth to your body than the fat it's replacing. And muscle costs a lot more calories to maintain, meaning your body will burn more calories at rest. That adds up to a slimmer you.

Weights are for boys. Aerobics are for girls

True, you'll find more women than men in aerobics classes. But you'll also find women in the weight room. That's because strength training benefits both men and women. Weight training helps women increase strength, decrease body fat, improve mood, reduce risk of injury and cut their chances of developing diabetes. Perhaps more important than all of that is strength training's ability to combat osteoporosis, a big concern as women age. Weight lifting boosts bone density, helping to keep your skeleton strong and functional.

Maxing out shows how fit you are

Walking into a gym, racking a huge amount of weights and lifting it once doesn't make you Mr. Universe. It might even end in injury. Fitness isn't about how many plates you can stack on your bench press. And it isn't about lifting more than the person next to you. At the gym, everyone has different goals. Some people are working to increase endurance, using smaller weights but pushing more repetitions. Other people are working to improve at a specific sport, like golf. Your goals are your goals. And your fitness is your fitness. Exercising at the gym is an athletic event where everyone who shows up wins.

There's no need to be noisy

The latest gym trend is to ban grunting. Planet Fitness and other fitness chains expressly request that exercisers keep the noise down, and many people appreciate the quiet, but it could hurt their members' workouts. Anyone who's been startled by a fellow gym-goer screaming his head off knows it's not a pleasant experience. But science suggests grunting is a good thing. A small Drexel University study noted an increase in strength during grunting. Researchers theorized that making noise while exercising taps into primal human wiring. And when you think about it, don't you feel a little stronger when you let loose a little noise?

Older bodies can't handle weights

As we age, some bodily changes are inevitable. But they're far fewer than most people think. Most of changes we attribute to passing years actually can be tied to reduced activity. In short: Your body isn't doing what it used to because you stopped doing what you used to. The solution is to build your strength and ability gradually. That reduces your chances of injury and actually improves your body's mechanisms for healing. There's no reason an older adult can't lift weights. Rather, your senior years are potentially the best time to strength train.