Exertion is the

physical Physical may refer to: * Physical examination, a regular overall check-up with a doctor * ''Physical'' (Olivia Newton-John album), 1981 ** "Physical" (Olivia Newton-John song) * ''Physical'' (Gabe Gurnsey album) * "Physical" (Alcazar song) (2004) * ...

or perceived use of

energy In physics, energy (from Ancient Greek: ἐνέργεια, ''enérgeia'', “activity”) is the quantitative property that is transferred to a body or to a physical system, recognizable in the performance of work and in the form of ...

.Newton's Third Law, Elert, Glenn. “Forces.” ''Viscosity – The Physics Hypertextbook'', physics.info/newton-first/. Exertion traditionally connotes a strenuous or costly ''effort'', resulting in generation of force, initiation of motion, or in the performance of

work Work may refer to: * Work (human activity), intentional activity people perform to support themselves, others, or the community ** Manual labour, physical work done by humans ** House work, housework, or homemaking ** Working animal, an animal t ...

. It often relates to

muscular Skeletal muscles (commonly referred to as muscles) are organs of the vertebrate muscular system and typically are attached by tendons to bones of a skeleton. The muscle cells of skeletal muscles are much longer than in the other types of muscle ...

activity and can be quantified, empirically and by measurable metabolic response.

Physical

physics Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which ...

, ''exertion'' is the expenditure of

against, or inductive of,

inertia Inertia is the idea that an object will continue its current motion until some force causes its speed or direction to change. The term is properly understood as shorthand for "the principle of inertia" as described by Newton in his first law ...

as described by

Isaac Newton Sir Isaac Newton (25 December 1642 – 20 March 1726/27) was an English mathematician, physicist, astronomer, alchemist, Theology, theologian, and author (described in his time as a "natural philosophy, natural philosopher"), widely ...

's third law of motion. In physics, force exerted equivocates work done. The ability to do work can be either positive or negative depending on the direction of exertion relative to gravity. For example, a force exerted upwards, like lifting an object, creates positive work done on that object. Exertion often results in force generated, a contributing dynamic of general motion. In

mechanics Mechanics (from Ancient Greek: μηχανική, ''mēkhanikḗ'', "of machines") is the area of mathematics and physics concerned with the relationships between force, matter, and motion among physical objects. Forces applied to objec ...

it describes the use of

force In physics, a force is an influence that can change the motion of an object. A force can cause an object with mass to change its velocity (e.g. moving from a state of rest), i.e., to accelerate. Force can also be described intuitively as a ...

against a body in the direction of its

motion In physics, motion is the phenomenon in which an object changes its position with respect to time. Motion is mathematically described in terms of displacement, distance, velocity, acceleration, speed and frame of reference to an observer and m ...

(see

vector Vector most often refers to: *Euclidean vector, a quantity with a magnitude and a direction *Vector (epidemiology), an agent that carries and transmits an infectious pathogen into another living organism Vector may also refer to: Mathematic ...

Physiological

Exertion, physiologically, can be described by the initiation of exercise, or, intensive and exhaustive physical activity that causes cardiovascular stress or a sympathetic nervous response. This can be continuous or intermittent exertion. Exertion requires, of the body, modified oxygen uptake, increased heart rate, and autonomic monitoring of blood

lactate Lactate may refer to: * Lactation, the secretion of milk from the mammary glands * Lactate, the conjugate base of lactic acid Lactic acid is an organic acid. It has a molecular formula . It is white in the solid state and it is miscible with w ...

concentrations. Mediators of physical exertion include cardio-respiratory and

musculoskeletal The human musculoskeletal system (also known as the human locomotor system, and previously the activity system) is an organ system that gives humans the ability to move using their muscular and skeletal systems. The musculoskeletal system prov ...

strength, as well as metabolic capability. This often correlates to an output of force followed by a refractory period of recovery. Exertion is limited by cumulative load and repetitive motions. Muscular energy reserves, or stores for biomechanical exertion, stem from metabolic, immediate production of ATP and increased oxygen consumption. Muscular exertion generated depends on the muscle length and the velocity at which it is able to shorten, or contract. Perceived exertion can be explained as subjective, perceived experience that mediates response to somatic sensations and mechanisms. A rating of perceived exertion, as measured by the ''RPE-scale'', or

Borg scale The Borg are an alien group that appear as recurring antagonists in the ''Star Trek'' fictional universe. The Borg are Cyborg, cybernetic organisms (cyborgs) linked in a Group mind (science fiction), hive mind called "the Collective". The Borg ...

, is a quantitative measure of physical exertion. Often in health, exertion of oneself resulting in cardiovascular stress showed reduced physiological responses, like

cortisol Cortisol is a steroid hormone, in the glucocorticoid class of hormones. When used as a medication, it is known as hydrocortisone. It is produced in many animals, mainly by the '' zona fasciculata'' of the adrenal cortex in the adrenal g ...

levels and mood, to stressors. Therefore, biological exertion is effective in mediating psychological exertion, responsive to environmental stress. Overexertion causes more than 3.5 million injuries a year. An overexertion injury can include sprains or strains, the stretching and tear of ligaments, tendons, or muscles caused by a load that exceeds the human ability to perform the work. Overexertion, besides causing acute injury, implies physical exertion beyond the person's capacity which leads to symptoms such as dizziness, irregular breathing and heart rate, and fatigue. Preventative measures can be taken based on biomechanical knowledge to limit possible overexertion injuries.

Psychological

sport psychology Sport psychology was defined by the European Federation of Sport in 1996, as the study of the psychological basis, processes, and effects of sport. Otherwise, sport is considered as any physical activity where the individuals engage for competi ...

, the perceived exertion of an exercise is how hard it seems to the person doing it. Perceived exertion is often rated on the Borg scale of 6 to 20, where 6 is complete rest and 20 is the maximum effort that an individual can sustain for any period of time. Although this is a psychological measure of effort, it tends to correspond fairly well to the actual physical exertion of an exercise as well. Additionally, because a high perceived exertion can limit an athlete's ability to perform, some people try to decrease this number through strategies like breathing exercises and listening to music.

References

External links

Measuring Physical Activity Intensity: Perceived Exertion (Borg Rating of Perceived Exertion Scale)
allowing exertion by proxy in sporting games {{Musculoskeletal physiology Physical exercise Exercise physiology Effects of external causes

Physical

Physiological

Psychological

See also

References

External links