2. Physical activity is defined as
bodily movements produced
by the skeletal muscles that
lead to energy expenditure. It
includes various activities
such as doing household
chores and walking. In
addition, physical activities
can be classified into four
domains: occupational,
domestic, transportation,
and leisure time.
3. 1. Occupational - These are work-related
activities such as climbing the stairs or
lifting objects.
2. Domestic - These are activities done at
home such as household chores.
3. Transportation - These are activities for
traveling or for commuting. Examples of
transportation-related activities are walking
and cycling.
4. Leisure Time - These are activities for
recreation. Examples of such activities are
sports, exercise, and hobbies.
4. EXERCISE- is the "planned,
structured, repetitive bodily
movements that someone
engages in for the purpose of
improving or maintaining
physical fitness or health."
Therefore, it is incorrect to use
physical activity interchangeably
with exercise because not all
physical activities may be
classified as exercise
5. THREE MAIN TYPES OF
PHYSICAL ACTIVITY
1.Aerobic activities - An
aerobic activity is also
known as a cardio or
endurance activity.
2. Muscle-strengthening
activities - Muscle-
strengthening activities are
collectively called
resistance training.
3. Bone-strengthening
activities - A bone-
strengthening activity is
6. According to the WHO, it is
important to be scientifically
informed about the
recommendations outlined by the
FITT (frequency, intensity, type, and
time) principle as these
recommendations are necessary to
produce health benefits.
Furthermore, the WHO also
endorses the “Global
Recommendations on Physical
Activity for Health,” which addresses
three age groups: 5-17 years old, 18-64
years old, and 65 years old and above
8. All body movements are fueled by energy.
The supply of energy released by the body is
proportional to the intensity and duration of
the physical activity one is engaging in.
Energy is stored in the body in various
forms such as carbohydrates, fats, and
proteins in phosphocreatine (also known as
creatine phosphate). The primary sources of
energy are carbohydrate and fat combined
with protein. The adenosine triphosphate
(ATP) is a molecule that serves as a usable
form of energy. It is a major fuel source for
the body. When the phosphate bonds of ATP
are broken, ATP releases large amounts of
9. The following paragraphs discuss the three
different systems of metabolism to transfer
stored energy to form ATP:
1.Phosphagen system - This system is the
fastest way of acquiring energy for the muscle.
Short bursts of intense activity such as five-
second sprints or jumping are fueled through
this energy system.
2. Anaerobic glycolysis - This system is the
second fastest way of obtaining energy to keep
the muscles contracting. The term anaerobic
means "without oxygen." Like the phosphagen
10. 3. Aerobic system -
Generally, not all physical
activities or sports finish
in less than three
minutes. Thus, a system
is needed to generate
energy for activities longer
than three minutes. This
system is the aerobic or
11. Over time, people who engage in
endurance training develop the ability
to use fat for energy more efficiently;
this ability lets the body avoid the use
of glucose and extends endurance.
Thus, well-trained athletes who engage
in stop-and-go activities like fartlek
training and endurance sports such as
marathons depend less on glycogen
and more on fatty acids.
In most cases, the phosphagen system
is always used first, followed by the
anaerobic and aerobic systems.
Sometimes, all three can operate
