Experts also recommend following these guidelines:
Wear protective gear for your hands and feet.
Never strength train in bare feet. Always wear gym shoes. Wear gloves to prevent your hands from becoming rough and callused and to improve your grip.
Before beginning a strength session, take the time to warm up your body. For example, walk on a treadmill for 5-10 minutes to increase blood flow to your muscles. Next, do some gentle stretching.
Start slowly; progress wisely.
Start with light weights that you can lift comfortably for 8-12 repetitions. Increase the weight gradually to the next set of weights. This goes for experienced exercisers, too, who have spent several weeks away from strength training. Get back into your routine slowly.
For example, think 2 counts up and 4 counts down.
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. 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. Keep your head and shoulders up, knees unlocked, 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.
Take a full breath with every repetition. Avoid holding your breath.
Recognize bad pain.
It's normal to experience light soreness in your muscles 24-48 hours after your training. However, deep soreness, especially in the joints, may indicate an injury.
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.
With free weights, use a spotter and proceed cautiously.
There's greater risk of dropping a weight or over-stretching a joint if you don't have someone to spot you when you work with free weights.
Be wise with rubber tubing and bands.
Make sure they do not have 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. Hold each stretch 10-30 seconds.
Rest between strength sessions.
Your muscles need time to rebuild and repair themselves. That goes for abdominal muscles, too.