Physical Fitness and Its Components

Introduction[edit | edit source]

Example of Physical Activity

Physical activity is defined as any bodily movement produced by skeletal muscles that results in energy expenditure[1]. The energy expenditure can be measured in kilocalories. Physical activity in daily life can be categorized into occupational, sports, conditioning, household, or other activities.[2]

Exercise is a subset of physical activity that is planned, structured, and repetitive and has as a final or an intermediate objective the improvement or maintenance of physical fitness.[2]

Physical fitness is a set of attributes that are either health- or skill-related. Being physically fit has been defined as "the ability to carry out daily tasks with vigor and alertness, without undue fatigue and with ample energy to enjoy leisure-time pursuits and to meet unforeseen emergencies"[2] The degree to which people have these attributes can be measured with specific tests.

Physical fitness measures are closely allied with disease prevention and health promotion, thus it is common and appropriate to measure components of physical fitness before preventive and rehabilitative programs. [3]Physical fitness can be modified through regular physical activity and exercise. Physical fitness components have been shown to have a significant positive relationship with enhanced outcomes in physical activity, including sports participation.[4]

Components of Physical Fitness[edit | edit source]

Physical fitness can be broadly divided into Metabolic fitness, Health- related and Skill-related.

Metabolic Fitness[edit | edit source]

Example of Exercise

It depicts the physiological systems' state of health when they are at rest.

  1. Blood pressure- It involves indirect measuring the effectiveness of the heartbeat, adequacy of blood volume and presence of any obstruction to vascular flow through the use of sphygmomanometer and a stethoscope.  Normal BP is 120/80
  2. Pulse rate- It is the number of throbbing sensations felt over a peripheral artery when the heart beats. Normal ranges from 60 to 100 pulses per min.
  3. Blood insulin- Insulin test measures blood samples for the amount circulating insulin, responsible for blood glucose usage by surrounding tissue. Normal values are 5 to 20µm/mL while fasting. Lower than normal suggest Type 1 diabetes and above normal level suggests Type 2 diabetes. [5]

Health-Related Fitness[edit | edit source]

Good health have a strong relationship with health related components of physical fitness because it determines the ability of an individual to perform daily activities with vigor and demonstrate the capacities associated with low risk of premature development of the hypokinetic diseases.[3]It is also known as physiological fitness.

The main aims of health-related fitness testing are :

  • Educating clients about their present health-related fitness status in relationship to standard age and sex- matched normative values
  • Providing data that are helpful for making clinical decision while prescribing exercises to address all fitness components
  • Collecting baseline and follow up data that allow evaluation of progress by exercise program participants
  • Motivating participants by establishing SMART goals
  • Stratifying cardiovascular risk[3]

The components of health-related fitness includes: body composition, muscular endurance, muscular strength, cardiovascular endurance and flexibility.

Body Composition[edit | edit source]

Body composition can be expressed as the relative percentage of body mass that is fat and fat-free tissue using a two-compartment model. It can be measured with both laboratory and field techniques that vary in terms of complexity, cost, and accuracy. Anthropometric methods are: Body mass index, Circumferences and Skinfold measurements. Hydrodensitometry weighing, plethysmography are some methods used in lab.[3]

  1. Skin fold thickness
  2. BMI
  3. Waist to hip ratio

-Skin fold thickness- measurements involve measuring skin and subcutaneous adipose tissues at several different standard anatomical sites around the body and converting these measurements to percentage body fat. The anatomical sites include:

For Males:

  • Chest fold
  • Abdominal fold
  • Thigh fold

Body density = 1.10938 & 0.0008267 (sum of three skinfolds) + 0.0000016 (sum of three skinfolds)2 & 0.0002574 (age) [SEE 0.008 or ~3.4% fat]

For Female:

  • Triceps fold
  • Suprailiac fold
  • Thigh fold

Body density = 1.099421 & 0.0009929 (sum of three skinfolds) + 0.0000023 (sum of three skinfolds)2 & 0.0001392 (age) [SEE 0.009 or ~3.9% fat]

*SEE: Standard error of estimate[6][3]

-BMI- Key index for relating a person’s body weight to height.

  BMI= M/(H*H), where M= body mass in kilograms and H= height in meters

(A higher BMI score usually indicates higher levels of body fat)

-Waist to hip ratio- Measured using a tape measure around the waist and the largest hip circumference. The ratio is a simple calculation of the waist girth divided by the hip girth. [5]

Risk category Women Men
Very Low <70 cm (27.5 in) <80 cm (31.5 in)
Low 70–89 cm (28.5–35.0 in) 80–99 cm (31.5–39.0 in)
High 90–109 cm (35.5–43.0 in) 100–120 cm (39.5–47.0 in)
Very High >110 cm (>43.5 in) >120 cm (>47.0 in)

Muscular Fitness[edit | edit source]

It includes muscular endurance and strength. They determine bone mass, glucose tolerance, musculo-tendinous integrity, and ability to carry out ADLs. Muscle function tests are very specific to the muscle group tested , the type of contraction, the velocity of muscle movement, the type of equipment, and the joint range of motion.[3]

Muscular Strength: It is the muscle's ability to exert force at high intensities over short periods of time. Static or isometric strength can be assessed by using various devices such as dynamometer and tensiometers. 1 repetition maximum (1- RM), the greatest resistance that can be moved through the full range of motion in a controlled manner with good posture, is the standard for dynamic strength assessment.[3][5]

The following represents the basic steps in 1-RM (or any multiple RM) testing following familiarization/practice sessions:

  1. The subject should warm up by completing several submaximal repetitions.
  2. Determine the 1-RM (or any multiple RM) within four trials with rest periods of 3 to 5 minutes between trials.
  3. Select an initial weight that is within the subject’s perceived capacity (~50%–70% of capacity).
  4. Resistance is progressively increased by 2.5 to 20 kg until the subject cannot complete the selected repetition(s); all repetitions should be performed at the same speed of movement and range of motion to instill consistency between trials.
  5. The final weight lifted successfully is recorded as the absolute 1-RM or multiple RM.[3]

Muscular Endurance: It is the ability of muscle group to execute repeated contractions over a period of time sufficient to cause muscle fatigue, or to maintain a specific percentage of the maximal voluntary contraction for a prolonged period of time. Absolute muscular endurance is the total number of repetitions at a given amount of resistance is measured. Relative muscular endurance is the number of repetitions performed at a percentage of the 1 -RM (e.g: 75%) which is in both pre- and post-testing.[3]A simple field test such as the maximum number of push-ups that can be performed without rest may be used to evaluatethe endurance of upper body muscles.

Cardiorespiratory Endurance[edit | edit source]

Cardiorespiratory fitness is related to the ability to perform large muscle, dynamic, moderate to high intensity exercise for prolonged periods. The performance depends upon the functional state of the respiratory, cardiovascular, and skeletal muscle systems. The criterion measure of cardiorespiratory fitness is determined by maximal oxygen uptake (VO2max).[3]The best measure of cardio-respiratory fitness is VO2 max, volume (V) of oxygen used when a person reaches his or her maximum (max) ability to supply oxygen (O2) to muscle tissue during exercise. [5]

Flexibility[edit | edit source]

Flexibility is the ability to move a joint through its complete range of motion. It is important in the ability to carry out ADLs and in athletic performance. It depends on a number of specific variables including distensibility of the joint capsule, adequate warm-up, and muscle viscosity. Flexibility is joint specific, thus, no single flexibility test can be used to evaluate total body flexibility. Goniometers, inclinometers, electrogoniometers, the Leighton flexometer and tape measures are some common devices to measure flexibility in degrees. Sit and reach test is one of the flexibility tests.[3]

Skill-related Fitness[edit | edit source]

It is also known as performance-related fitness components. It is associated with athletic competition but should be considered in the overall fitness of all individuals. These components are pertaining with the athletic ability of an individual. There are 6 components of physical fitness: balance, co-ordination, agility, speed , power, and reaction time.

Balance[edit | edit source]

Balance is the ability of an individual to maintain their line of gravity within their base of support. It can be classified into static and dynamic. Balance is control by three different system: somatosensory, visual and vestibular system. [7]It can be assessed by various outcome tools such as berg balance scale, BESTest, etc.[8]

1)One leg stance test- Individual is asked to stand on 1 leg for 10s with eyes open or closed

2)Sharpened Romberg’s test- Individual stands with both feet in tandem (feet touching heel to toe) with eyes closed to mask the problem with balance.

3)Time up and Go test- This balance test measures the time needed to rise to standing from a chair, walk 3m, turn, walk back to chair and sit down. [5]

Coordination[edit | edit source]

It is the ability to use the senses, such as sight and hearing, together with body parts in performing motor tasks smoothly and accurately.[2]Alternate hand wall toss test is one the test via which co-ordination can be assessed. The below attached video explains this test.

  1. Begin by explaining what the person needs to do in this test.
  2. The ball is struck against the wall and caught by the other hand.
  3. This has to be continued until 30 seconds.


Finger to Nose test- This test is designed to observe the smoothness and timing of arm movement. The individual is asked to repetitively touch the nose using the index finger and then to touch the clinician’s outstretched finger.[5]

Power[edit | edit source]

It is the rate at which one is able to exert maximal force.[10]Vertical jump test and hop test are some examples of power testing for lower extremity. Medicine ball throw test can be used to assess upper extremity power.

Vertical jump test:

Materials required:

  1. A wall with marked numbers.
  2. Clearly defined Jumping area.
  3. Ruler or measuring tape for precise measurements.


  1. The participant is instructed to stand still shoulder width apart on a designated spot.
  2. Measurements are taken by a tester, marking the standing reach height.
  3. A clear instruction/demonstration of the correct jumping technique is given.
  4. The participant's vertical jump height is recorded based on the difference between the jump reach and the standing reach.
  5. Three attempts can be given and recorded.

Instruction to be given:

  1. Bend the knees and hip, then swiftly jump.
  2. Use maximal force and reach as high as possible.


Medicine ball throw test:

  1. The medicine ball is securely held by the participant while standing with feet shoulder-width apart.
  2. A stable overhead position is assumed by the participant, ensuring the elbows are extended.
  3. The ball is propelled upward with maximum force, employing a full-body movement.
  4. The height attained by the thrown ball is measured as an indicator of upper body power.


A boy performing Illinois agility testing

Agility[edit | edit source]

Agility is defined as “a rapid whole-body movement with change of velocity or direction in response to a stimulus”.[10] It performs a series of explosive power movements in a rapid succession in opposing directions.

Reaction time[edit | edit source]

Reaction time is related to the time elapsed between stimulation and the beginning of the reaction to it.[10] Reaction time is affected by several variables including attentive, cognitive and motor functions. Three basic reaction time paradigms have been described:

  1. simple reaction time has a single stimulus and a single predefined response,
  2. recognition reaction time has several false stimuli mixed with one correct stimulus prompting the response, and
  3. choice reaction time involves multiple stimuli and differing responses for each stimulus. [13]

It can be assessed via Drop-Ruler test. Please watch the video below to understand this test.


  1. The ruler is dropped from a predetermined height by the experimenter.
  2. The centimeter difference between the initial position and the final landing point is measured.
  3. The measurement process is repeated multiple times to enhance accuracy.
  4. Conclusions are drawn based on the collected data regarding the ruler's descent in terms of centimeter displacement.


Speed[edit | edit source]

It relates to the ability to perform a movement within a short period of time. . Speed combined with strength will provide power and force. Sprint test is one of the example of the test that can be used to examine person's speed.


  1. The starting position is assumed.
  2. A signal is given to initiate the sprint.
  3. The 40-meter sprint distance is covered.
  4. The time upon completion is recorded.


Related pages[edit | edit source]

References[edit | edit source]

  1. WHO- Physical activity.
  2. 2.0 2.1 2.2 2.3 Caspersen CJ, Powell KE, Christenson GM. Physical activity, exercise, and physical fitness: definitions and distinctions for health-related research. Public health reports. 1985 Mar;100(2):126.
  3. 3.00 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 3.10 3.11 American College of Sports Medicine's Guidelines for Exercise Testing and Prescription- 11th editions. Chapter 4- Health Related Physical Testing and Interpretation.
  4. Farley JB, Stein J, Keogh JW, Woods CT, Milne N. The relationship between physical fitness qualities and sport-specific technical skills in female, team-based ball players: A systematic review. Sports medicine-open. 2020 Dec;6(1):1-20.
  5. 5.0 5.1 5.2 5.3 5.4 5.5 Catherine Rush Thompson. Prevention Practice and Health Promotion: A Health Care Professional’s Guide to Health, Fitness, and Wellness. 2nd edition, slack incorporated, 2014
  6. McLester CN, Dewitt AD, Rooks R, McLester JR. An investigation of the accuracy and reliability of body composition assessed with a handheld electrical impedance myography device. European Journal of Sport Science. 2018 Jul 3;18(6):763-71.
  7. Dunsky A. The effect of balance and coordination exercises on quality of life in older adults: a mini-review. Frontiers in aging neuroscience. 2019:318.
  8. Viveiro LA, Gomes GC, Bacha JM, Junior NC, Kallas ME, Reis M, Jacob Filho W, Pompeu JE. Reliability, validity, and ability to identity fall status of the Berg Balance Scale, Balance Evaluation Systems Test (BESTest), Mini-BESTest, and Brief-BESTest in older adults who live in nursing homes. Journal of geriatric physical therapy. 2019 Oct 1;42(4):E45-54.
  9. Move academy. Fitness Test - Alternate Wall Toss. Available from:
  10. 10.0 10.1 10.2 Farley JB, Stein J, Keogh JW, Woods CT, Milne N. The relationship between physical fitness qualities and sport-specific technical skills in female, team-based ball players: A systematic review. Sports medicine-open. 2020 Dec;6(1):1-20.
  11. Vertical Jump Test. Available from:
  12. Fitness Test - Overhead Medicine Ball Throw. Available from:
  13. Kelly KM, Kiderman A, Akhavan S, Quigley MR, Snell ED, Happ E, Synowiec AS, Miller ER, Bauer MA, Oakes LP, Eydelman Y. Oculomotor, vestibular, and reaction time effects of sports-related concussion: video-oculography in assessing sports-related concussion. The Journal of head trauma rehabilitation. 2019 May;34(3):176.
  14. Measurement at Home Challenge: Reaction Time. National Physical Laboratory. Available from: