Muscle fitness can mean you have muscles that can lift heavier objects (strength) or muscles that will work longer before becoming exhausted (endurance). As you increase your muscle fitness, you will notice that you can carry heavy grocery bags more easily, pick up children without feeling as much strain, or carry heavy items longer before becoming too tired to continue. Having stronger muscles also protects your joints.
One part of muscle fitness is strengthening the muscles of your trunk. This strengthening is called core stabilization. It can help you have better posture and balance, and help protect you from injury.
