The terms "muscle tone" and "muscle strength" are not interchangeable. These two terms refer to very distinct qualities about muscle function. Muscle tone refers to the resistance and tension of a muscle at rest, while muscle strength refers to the power behind a muscle contraction. Exercise that builds muscle and strength also increases muscle tone, which is a measure of one function of a healthy muscle. You don't have to do separate exercises or stretches to increase your muscle tone.
Muscle tone is a measure of your muscle's resistance to stretch when the muscle is not undergoing a conscious contraction. Simply put, your muscle tone refers to what your muscles do when you aren't using them. A well-toned muscle maintains proper posture and alignment when you're at rest. This position is held due to tiny micro-contractions that occur all the time, except during REM sleep. Stretching your muscles frequently may prevent a loss in muscle tone from bulking as your muscles build, but it isn't clear whether stretching has any effect on muscle tone at all.
Muscle strength refers to what your muscles do when they aren't at rest. When you deliberately move a muscle, your brain sends signals to the individual fibers of your muscle, causing your muscles to contract. The power of this contraction is dependent on your muscle mass and can be built up through weight training and exercise. Larger muscles tend to look more defined underneath the skin, satisfying what is often incorrectly referred to as the "tone" of your muscles.
Muscle definition is often mistakenly referred to as muscle tone. The definition of a muscle is the appearance underneath the skin. If you're trying to improve the appearance of your muscles, losing excess body fat through frequent exercise and proper eating habits can increase the definition of your body. Muscle definition can be seen as a marker of exceptional health and wellness, even though it is medically unrelated to strength. All exercises affect the strength of your muscles, which builds muscle definition and muscle tone simultaneously. Your workout will improve both qualities of the muscles when combined with a healthy lifestyle.
Improving Muscle Tone and Strength
By working out or exercising your muscles, your muscle tone and strength will both improve simultaneously. Stronger muscles are better able to hold posture when you're at rest, so building on your strength will automatically give you the benefits of good muscle tone. Muscle tone can also vary from person to person, with some people naturally having better posture than others. Stretching muscles before and after a workout will prevent them from stiffening with bulk, which will improve your muscle tone and posture when your muscles are at rest.
Max Roman Dilthey is a science, health and culture writer currently pursuing a master's of sustainability science. Based in Massachusetts, he blogs about cycling at MaxTheCyclist.com.