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Healthy Muscles

Healthy Muscles


Muscles get stronger when they are used regularly, but especially when they have to work against something. This is called "resistance."

For example, you use your arm muscles when you bend your arm at the elbow. But when you do the same movement with something heavy in your hand, your arm muscles are working against more resistance.

"Resistance training" means using things like weights, rubber tubing, or certain exercises to make your muscles stronger. It's a 3-step process:

Step 1: Stress.

When you exercise against resistance, you stress your muscles slightly but not to the point of serious damage or injury.

Step 2: Recovery (rest).

When you rest, your body rebuilds the muscles and the connective tissues between them (joints, tendons, and ligaments). This prepares them for the next time they will be stressed.

Step 3: Repeated stress.

When you stress the same muscles again, the process is repeated. The muscles get stronger over time.

A resistance-training program to increase muscle fitness can include:

Benefits of strength training

Strength training has many benefits, including:

  • Stronger muscles, which help protect your joints.
  • Less body fat.
  • Stronger bones.
  • Better posture and balance.
  • Lower blood sugar.
  • Less stress.
  • Fewer body aches.
  • More energy.

Stronger muscles can work longer before they get tired. Many daily activities require you to move, lift, or control a weight. Muscle strength will help you do these activities with less stress on your muscles. You'll notice that you can lift heavy grocery bags more easily. You can pick up children without feeling as much strain. And you can carry heavy items longer before you get tired.

Doing the right amount of strength training

Experts say it's best to do exercises to strengthen bones and muscles at least 2 times each week.footnote 1 For example, you could do weight training or stair climbing.

How many repetitions and sets you do of a specific exercise depends on your goals.

  • Repetitions are the number of times you continuously perform each exercise. For example, if you lift a dumbbell up and down once, that's 1 repetition (or rep). If you lift it 5 times, that's 5 reps.
  • Sets are the number of times you do a certain number of repetitions. For example, if you lift the dumbbell 15 times, take a rest, and then lift it another 15 times, you have done 2 sets of 15 reps each.

If your goal is to gain strength, do a few sets of a few reps with heavy weights. If you want to increase muscle tone and endurance, do a few sets of many reps with light or medium weights.

One way is to use a weight that makes your muscles tired after 8 to 12 repetitions of each exercise. As you build muscle strength, you'll notice that you can do more and more of each exercise. Some people will see a change in the way their muscles look. But other people won't see a change for a long time. A more important sign of progress is how many repetitions and sets of an exercise you can do, or how much easier it feels to do them. This means that your muscle fitness has improved.

Building your muscle fitness safely

Strength training is an important part of overall physical fitness. Here's how to build your muscle fitness safely.

  • If you can, learn from a professional.

    Your training can be from a local YMCA, a fitness club, or an experienced professional trainer. Set a goal such as body building, toning and shaping certain body areas, or improving performance in a certain sport.

  • Don't forget to warm up.

    Take 5 to 10 minutes to walk or jog in place.

  • Learn the proper form for each exercise, and then always use it.

    The proper form ensures that you get the most out of each exercise. It also helps prevent injuries. A good trainer will teach you about proper form.

  • Give your body time to adjust.

    Allow at least 2 weeks for your muscles and connective tissues to adjust to the new stresses and strains of weight training. Start by lifting weights that are lighter than you can manage. This helps you tell the difference between the normal aches and pains of weight training and the pains of overuse or real damage.

  • Work slowly, and move your muscles through their full range of motion.

    Do fewer repetitions slowly, using the entire length of the muscle. This works better than doing many repetitions quickly with only a short part of the muscle.

  • Learn how to breathe properly when you work with weights.

    Exhale when you push against the weight. Don't hold your breath at any point. Inhale when there is little or no resistance.

  • If you can, ask a trainer for help.

    If you are starting weight training on your own, here is a basic plan you could follow.

    • Start with 2 to 3 sets of 8 to 12 repetitions. Start with a weight that's hard to lift on the 8th repetition.
    • Increase the weight you lift when you can do 12 repetitions. With the increased weight, you might have to go back to 8 repetitions. When you can do 12 repetitions with the increased weight, try adding a little more weight.
  • Vary your program.

    Variety keeps your interest up and injuries down. Mix muscle strengthening with flexibility and aerobic work. Also, vary your work by switching between:

    • Your upper body and lower body.
    • Free weights (barbells) and machines.
    • Heavier weights with fewer repetitions and lighter weights with more repetitions.

By starting slowly and using the right technique, you may find that weight training is an enjoyable and effective way to build strength.



  1. U.S. Department of Health and Human Services (2018). Physical Activity Guidelines for Americans, 2nd ed. Accessed July 9, 2018.


Current as of: October 10, 2022

Author: Healthwise Staff
Medical Review:
E. Gregory Thompson MD - Internal Medicine
Adam Husney MD - Family Medicine
Kathleen Romito MD - Family Medicine
Heather Chambliss PhD - Exercise Science

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