"Strength training is one of the safest activities, as long as it's performed with safety in mind," says Ches Jones, PhD, associate professor of health science at the University of Arkansas. Strength training is great for health, but only if you do it safely and properly. Here's how to stay safe and injury-free when you strength train.

No matter what your fitness level, you should give your strength-training program a safety check-up. The best strategy is to hire a qualified, certified personal trainer. Although regular sessions with a trainer can be costly, you can still benefit from one or two sessions, says Michael Wood, CSCS, director of the Sports Performance Group in Boston, Massachusetts. If you're new to strength training, ask to be introduced to exercises and equipment. If you're a veteran, have your form checked. Also, if you exercise at home, ask the trainer to evaluate your equipment.

Guidelines

Experts also recommend following these guidelines:

Wear protective gear for your hands and feet.

Always wear gym shoes and never strength train in bare feet. Wear gloves to prevent your hands from becoming rough and callused and to improve your grip.

Warm up.

Before beginning a strength session, walk on a treadmill or ride a stationary bike for 5-7 minutes to increase blood flow to your muscles.

Start slowly; progress wisely.

Start with light weights that you can lift comfortably for 8-15 repetitions. Increase the weight no more than 3%-5% at a time, Wood says. This goes for experienced exercisers, too, who have spent 2-3 weeks away from strength training. Get back into your routine slowly.

Lift slowly.

Think two counts up and four counts down, advises Gregory Florez, founder and CEO of First Fitness Inc.

Understand each exercise.

Know which muscles should be working and which muscles should be stabilizing your body. Also, identify the correct range of motion for each exercise, Wood says. In a lunge, for example, know whether you should take a small step or a giant step.

Use good posture.

With bad posture, you could activate and injure a muscle group that's not supposed to be working. Florez advises using the "athletic ready stance" with your head and shoulders up, knees bent, and shoulders and hips in line. If you can't maintain correct posture, you're either lifting a weight that's too heavy or doing the exercise incorrectly. Check your posture by lifting in front of a mirror.

Breathe.

Take a full breath with every repetition. And don't ever hold your breath.

Recognize bad pain.

It's okay if you experience light soreness in your muscles 24-48 hours after your training, Florez says. But deep soreness, especially in the joints, indicates that you've overdone it.

Work front-to-back and side-to-side.

Every muscle has an opposing muscle, such as quadriceps and hamstrings or abdominals and lower back. If you train one muscle, train the opposing muscle to avoid creating imbalances in your body that can lead to injury.

Position yourself properly when using machines.

Know where you should adjust your seat and align your joints. Beware of home equipment that is more than five years old, Florez warns. It may not have safety features like adjustability and lumbar support.

With free weights, use a spotter and proceed cautiously.

"Because you don't have a pre-selected range of motion, there's greater risk of dropping a weight or over-stretching a joint," Florez explains.

Be wise with rubber tubing and bands.

Make sure they have no cuts or tears, keep them out of extreme heat or cold, and secure them well.

Stretch after your workout.

When muscles are contracted, they shorten. "Stretching lengthens muscles and allows them to release tension," Wood says. Hold each stretch 30-60 seconds.

Allow 48 hours of rest between strength sessions.

Your muscles need the time to rebuild and repair themselves. That goes for abdominals muscles, too. "Your abs are a muscle and should be given adequate recovery time," Florez says.