Components Of Fitness And The Effects Of Exercises

Avatar for Hadyn Luke Hadyn Luke posted this on Tuesday 14th of November 2023 Hadyn Luke 14/11/2023


Components Of Fitness And The Effects Of Exercises

The subject of fitness is very complex and comprises many different components. The word “Fitness” is often linked to being healthy, having good stamina, being supple and eating a well balanced diet.

Fitness is the ability to meet the demands of life safely and effectively, without exhaustion or undue stress.

Fitness can be divided into two main components:

Cardiovascular Fitness

Cardiovascular Fitness refers to the ability of the heart, lungs, and circulatory system to take in, transport and use oxygen, so that the working muscles have adequate supply.

It is sometimes referred to as “stamina”, “endurance” or “aerobic fitness”. Good cardiovascular fitness will enable the lungs to draw in more oxygen from the air and maximise its uptake into the bloodstream. It will increase the ability of the muscles to utilise oxygen.

Cardiovascular exercise is defined as any activity, which is rhythmic, continuous, and uses large muscle groups under moderate to low tension over an extended period of time. Examples are walking, swimming, cycling and jogging. Aerobic training to dedicated to improving the cardiovascular system, which consists of the following:


As a response to regular CV training, the left ventricle increases its volume and its muscular walls become stronger. Each heartbeat pumps out a greater volume of blood (stroke volume), which is then transported around the body. As stroke volume increases this, in turn, lowers the heart rate .i.e. fewer heart beats will be needed to pump out a given volume of blood. In other words, each heart beat becomes more powerful.


Capillarisation (the growth of new capillaries) increases around the alveoli, enabling greater gaseous exchange. The lungs grow bigger and more of the existing lung tissue will be utilised. The lungs grow bigger and more of the existing lung tissue will be utilised. More air can be sucked into the lungs thus increasing the amount of oxygen that is available to be exchanged for Carbon Dioxide (Co2). The breathing process becomes more efficient as the respiratory muscles become stronger. Their ability to continue to work for longer durations at higher levels of exercise also increases.


In order to meet the demands of increased activity levels there is an increase in both blood volume and red blood cells, which contain haemoglobin. Increased capillarisation also occurs in and around the muscle tissue. This increase the delivery of fresh oxygenated blood to the working areas. Increased capillarisation also occurs in and around the heart, allowing both heart and lungs to function more efficiently and for longer durations.

Blood Pressure

As a result of increased capillarisation there are more avenues through which the blood can flow. Over time, once the body has responded and adapted to the effects of aerobic training, there will be a long term decrease in overall blood pressure.

Aerobic training will also promote physiological improvements in the muscular and skeletal systems as follows:

  • Local Muscular Endurance – Individual muscle groups that have been trained will develop greater endurance. This is the result of an increase in both the size and number of mitochondria. There is also an increase in the amount of aerobic enzyme activity, which enables the muscles to extract more oxygen from the blood and use fats as a source of fuel. These developments enable muscles to produce aerobic energy for longer durations and at higher intensities. This means that less lactic acid will be produced. Muscles are able to continue working harder for longer before fatigue sets in.
  • Reduced risk of osteoporosis – Controlled stresses imposed by the pull of the muscles on the bones (resistance) stimulate the body to take up more mineral salts, which strengthen bone tissue.

ACSM Guidelines For Cardiorespiratory Fitness

The American College of Sports Medicine (ACSM) is a professional organization that promotes and integrates scientific research, education, and practical applications of sports medicine and exercise science.
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Individuals who are already physically active (in aerobic activity) require intensities and session durations at the higher end of the range to further improve their CV fitness.

For most individuals intensities within the range of 77% to 90% HR max are sufficient to achieve improvements in CV fitness when combined with an appropriate frequency and duration of training.

De-conditioned or unconditioned clients require a 64-70% range with session durations between 20-30 minutes.

Muscular Endurance

Muscular endurance is the ability to keep contracting a muscle or a group of muscles against resistance, such as weights or body weight, for a long time. Muscular endurance is important for any endurance sport, such as running, cycling, or swimming, and also for many team sports, such as football, basketball, or rugby2. Muscular endurance can be improved by doing strength and cardiovascular training that work large muscle groups with moderate load and high volume. Some examples of exercises that can improve muscular endurance are push-ups, squats, abdominal crunches, planks, lunges, and burpees.

This type of fitness refers to the ability of a muscle or muscle group to overcome a low to moderate resistance repeatedly. Training for muscular endurance usually involves a high number of repetitions and a comparatively low resistance using bodyweight, bands, free weights and resistance machines.

High Reps – Low Resistance

Muscular Strength

This type of fitness refers to the ability of a muscle or muscle group to exert maximum force against a high resistance. Training for muscular strength involves using a low number of repetitions and a high resistance using body weight, bands, free weights and resistances machines.

Low Reps – High Resistance


Flexibility refers to the range of movement possible at a joint.

Different joint structures have different capacities for movement according to their type (ball and socket, hinge etc.).

The agonist or prime mover creates movement at a freely moveable or semi-moveable joint.

The range through which the joint will move will be determined by the structure of the joint and the muscles and connective tissue which surround it.

Having a restricted range of movement, and being inflexible makes joints prone to injury.

Maintaining full potential range of movement can improve performance, reduce the risk of injury as well as assisting in daily tasks.

ACSM guidelines for improving flexibility

  • Frequency: A minimum of 2-3 sessions per week
  • Intensity: Slow and controlled to the point of mild tension: 3-4 reps per muscle group, whole body approach
  • Time: Maintenance – 10-15 seconds. Developmental – 15- 30 seconds. PNF stretches – 6 seconds followed by 10-30 seconds assisted stretch
  • Type: Static Stretches

Motor Skills

Motor skills are the abilities to perform movements and tasks using the body’s muscles, nerves, and brain.

Motor skills can be classified into two major groups: gross motor skills and fine motor skills.

  • Gross motor skills involve the use of large muscle groups in the legs, arms, and torso, and are usually associated with continuous tasks such as walking, running, or jumping.
  • Fine motor skills involve the use of small muscles in the hands, wrists, or fingers, and are usually associated with precise tasks such as writing, drawing, or using a fork.

Motor skills are important for child development, physical fitness, and daily activities.

Motor skills rely on the nerve to muscle or brain to body relationship, referred to as neuromuscular responses.

These skills are specific to the activity and train the neuromuscular connections.

Examples are:

  • Balance: the ability to keep the body centred over a base.
  • Co-ordination: the ability to perform smooth and accurate movements – requiring good awareness and integration of senses, muscles and body positions involved in the movement.
  • Reaction time: the interval between a stimulus and a response
  • Speed: the pace/tempo of work, e.g. kph/rpm
  • Power: the amount of work done per unit of time. Power = strength x speed
  • Agility: ability to rapidly change a position of the entire body in space with speed and accuracy.

Skills Related Fitness

Skills related fitness relates to a specific sport of activity, where the emphasis is on developing the specific skills required, focusing, perhaps, on one of more of the different components, rather than involving a purely health-related approach that includes all the components of fitness in equal measure.

It involves examining the sport closely. For example, analysing the joint actions required, the muscle groups and type of contractions used, the range of movement necessary, whether explosive or continuous energy is required. These indicate which of the components of physical fitness would need to take precedence.

For example: Sprinting – Training would focus on strength and power to enable the explosive action out of the starting blocks. Less emphasis is placed on muscular endurance as the sprint itself over lasts around 10 seconds.

Factors that can affect skill related fitness include:

  • Skill level
  • Previous experience
  • Kinaesthetic awareness (awareness of where your body is in space)
  • Age
  • Gender
  • Somatotype

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