Many people strive to be fit. Fitness, after all, is synonymous with health.
Having a high level of overall fitness is linked with a lower risk of chronic
disease, as well as a better ability to manage health issues that do come up.
Better fitness also promotes more functionality and mobility throughout one’s
life span.
And in the short term, being active can help your day-to-day functioning, from
better mood to sharper focus to better sleep.
Simply put: Our bodies are meant to move, and they tend to function better
when we’re more fit.
That said, it’s also important to know that there are many different ways to be
fit (think of a ballet dancer versus a bodybuilder or a sprinter versus a
gymnast). And fitness does not have a singular “look.” In fact, appearance
can’t necessarily tell you about someone’s habits, whether they’re actually
physically active, or even whether they’re fit at all.
What It Means to Be Fit
According to the Physical Activity Guidelines for Americans set forth by the
U.S. Department of Health and Human Services (HHS), there are five
components of physical fitness.
● Cardiorespiratory Fitness
Your VO2 max is a commonly used
measure of this. It’s your body’s ability to uptake and utilize oxygen
(which feeds all of your tissues), something that is directly related to
your health and quality of life, says Abbie Smith-Ryan, PhD, professor
and director of the Applied Physiology Laboratory at the University of
North Carolina in Chapel Hill.
● Musculoskeletal Fitness
This includes muscle strength, endurance,
and power.
● Flexibility
This is the range of motion of your joints.
● Balance
This is your ability to stay on your feet and steady to avoid
falls.
● Speed
This is how quickly you can move.
A frequently cited peer-reviewed research paper from 1985 defined the
difference between the terms “physical activity” (bodily movement resulting in
energy expenditure), “exercise” (planned and structured physical activity), and
“physical fitness.” The paper defined physical fitness as a set of attributes that
people have or achieve that determines their ability to carry out daily tasks
with vigor and alertness, without undue fatigue. Cardiorespiratory endurance,
muscular endurance, muscular strength, body composition, and flexibility are
components that can be used to measure fitness, also according to that paper.
Types of Fitness
There are a few main components of fitness, all of which are important for
building a well-rounded exercise routine. Below, you will find the ones
included in the Physical Activity Guidelines for Americans, which HHS
highlights as the components that should be included in weekly exercise.
(It’s worth noting that many definitions of fitness include other components
as well, such as endurance, muscular endurance, power, speed, balance,
and agility — as mentioned above.)
Aerobic (Cardiovascular) Exercise for
Fitness
Aerobic exercise is the foundation of every fitness program — and for good
reason. Also called cardiovascular exercise or cardio, this type of physical
activity increases your heart rate and breathing rate, which improves your
cardiorespiratory fitness, according to the American Heart Association.
Aerobic exercise includes activities like brisk walking, running, cycling,
swimming, aerobic fitness classes (like kickboxing), tennis, dancing, yard
work, tennis, and jumping rope, per the Physical Activity Guidelines.
Strength Training
Strength training is an important way to improve mobility and over functioning,
particularly as you get older. “As you age, you lose muscle mass, which can
have a significant impact on the quality of life. Strength exercises build bones
and muscle, and more muscle protects your body from falls and the fractures
that can happen in older age,” says Robert Sallis, MD, a family medicine
doctor at Kaiser Permanente in Fontana, California, and chairman of the
Exercise Is Medicine initiative with the American College of Sports Medicine
(ACSM).
According to the ACSM, the definition of strength or resistance training is
exercise that is “designed to improve muscular fitness by exercising a muscle
or a muscle group against external resistance.” Activities that answer this call
include lifting weights, using resistance bands or your body weight, carrying
heavy loads, and even strenuous gardening, per the Physical Activity
Guidelines from HHS.
Flexibility and Mobility
Flexibility and mobility are both important components of healthy
movement, according to the International Sports Sciences Association.
However, they are not synonymous.
Flexibility refers to the ability of tendons, muscles, and ligaments to stretch,
while mobility refers to the body’s ability to take a joint through its full
range-of-motion.
There is no specific recommendation for the number of minutes you should
do activities that improve flexibility or mobility (such as stretching), and the
health benefits of those activities are not known because of a lack of
research on the topic, according to the Physical Activity Guidelines from
HHS. But the guidelines note that flexibility exercises are important for
physical fitness.
And the guidelines do recommend that older adults incorporate balance
training into their weekly fitness routine. Evidence suggests that regular
exercise that includes balance training can significantly reduce older adults’
risk of falls, which can cause serious and debilitating injuries, among other
consequences.