Topic Overview

Muscle fitness is one of three important types of overall physical fitness. The others are aerobic fitness and flexibility.

When you increase your muscle fitness, you'll notice that you can carry heavy grocery bags more easily, pick up children without feeling as much strain, or carry heavy items longer before you get too tired to continue.

Benefits of muscle fitness include:

• Stronger muscles, which also help protect your joints.
• Muscles that can work longer before getting tired.
• Less body fat.
• Stronger bones.
• Better posture and balance.
• Lower blood sugar.
• Less stress.
• Fewer body aches.
• More energy.

How do you get healthier muscles?

Muscles become 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:

1. Stress. When you exercise against resistance, you stress your muscles slightly but not to the point of serious damage or injury.
2. Recovery (rest). When you rest, your body rebuilds the muscles and the connective tissues between them (joints, tendons, and ligaments) in a way that prepares them for the next time they will be stressed.
3. Repeated stress. When you stress the same muscles again, the process is repeated, and the muscles gradually become stronger.

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

• Basic muscle-conditioning exercises such as push-ups, leg lifts, and other common exercises.
• Resistance training with rubber tubing or stretchable bands.
• Weight training with free weights ("dumbbells") or weight-training equipment. See a picture of muscle-strengthening exercises using weights.
• Doing heavy housework and yard work, such as scrubbing the bathtub, washing walls, tilling the garden, or pulling weeds, on a regular basis.

How can you strengthen your core?

One part of muscle fitness is strengthening the muscles of your trunk. This is called core stabilization.

Core stability benefits everyone, from older people to top professional athletes. It can help you have better posture and balance, and it can help protect you from injury.

• Fitness: Increasing Core Stability

How often should you do exercises to strengthen muscles?

Experts say it's best to do exercises to strengthen muscles at least 2 times each week.^{footnote 1} Examples include weight training or stair climbing on 2 or more days that are not in a row.

"Repetitions" and "sets" are terms used to describe how many times you do a specific exercise.

• 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.

The number of repetitions and sets you do depends on your goals. If you want to gain strength, do a few sets of a few reps with heavy weights. But you may want muscular tone and endurance, which means a few sets of many repetitions with light or medium weights.

For best results, use a resistance (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 others will not see a change for a long while. 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.

How can you get started?

It's always a good idea to talk to your doctor before starting a resistance-lifting program, especially if you have high blood pressure, heart disease, or joint problems.

• Begin with professional instruction 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, then always use it. The proper form ensures that you get the most out of each exercise and helps prevent injuries. A good trainer will teach you about proper form.
• 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. Fewer repetitions that are done slowly, using the entire length of the muscle, are more effective than many repetitions that are done quickly with only a short part of the muscle.
• Learn how to breathe properly when working with weights. Exhale when pushing against the weight. Don't hold your breath at any point. Inhale when there is little or no resistance.
• When you are ready, ask your trainer for guidance on:
  • How often to increase sets and repetitions. In general, do 1 or 2 sets of 8 to 12 repetitions. Older adults and people who are frail can do 10 to 15 repetitions with less weight.
  • When to increase weight. Start with a weight you can lift 8 to 12 times but that gets hard to lift by the last repetition. When it gets easier, add a little weight and go down to 8 repetitions, then gradually build up to 12 repetitions again.
• Vary your program. Variety keeps your interest up and injuries down. Mix muscle strengthening with flexibility and aerobic work. Also, vary your work by alternating 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.