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.¹ Examples include weight training or stair climbing on 2 or more days that are not in a row.