Exercise physiology

Fatigue (also called exhaustion, tiredness, languidness, languor, lassitude, and listlessness) is a subjective feeling of tiredness which is distinct from weakness, and has a gradual onset.

Adenosine triphosphate (ATP) is a nucleoside triphosphate, a small molecule used in cells as a coenzyme.

Anabolic steroids, also known more properly as anabolic-androgenic steroids (AAS), are steroidal androgens that are structurally related to and have similar effects as testosterone in the body.

The citric acid cycle – also known as the tricarboxylic acid (TCA) cycle or the Krebs cycle – is a series of chemical reactions used by all aerobic organisms to generate energy through the oxidation of acetyl-CoA derived from carbohydrates, fats and proteins into carbon dioxide and chemical energy in the form of adenosine triphosphate.

Gluconeogenesis (GNG) is a metabolic pathway that results in the generation of glucose from certain non-carbohydrate carbon substrates.

Glycogen is a multibranched polysaccharide of glucose that serves as a form of energy storage in animals and fungi.

Lactic acid is an organic compound with the formula CH3CH(OH)CO2H.

Muscle is a soft tissue found in most animals.

Pyruvic acid (CH3COCOOH) is the simplest of the alpha-keto acids, with a carboxylic acid and a ketone functional group.

Basal metabolic rate (BMR) is the minimal rate of energy expenditure per unit time by endothermic animals at rest.

Isometric exercise or isometrics are a type of strength training in which the joint angle and muscle length do not change during contraction (compared to concentric or eccentric contractions, called dynamic/isotonic movements).

Muscle contraction is the activation of tension-generating sites within muscle fibers.

Hypertrophy (IPA /haɪˈpɝːtrəfi/, from Greek ὑπέρ "excess" + τροφή "nourishment") is the increase in the volume of an organ or tissue due to the enlargement of its component cells.

A myokine is one of several hundred cytokines or other small proteins (~5–20 kDa) and proteoglycan peptides that are produced and released by muscle cells (myocytes) in response to muscular contractions.

Cardiovascular fitness is the ability of the heart, blood cells and lungs to supply oxygen-rich blood to the working muscle tissues and the ability of the muscles to use oxygen to produce energy for movement.

Exercise-induced asthma, or E.

Ventricular hypertrophy is the thickening of the ventricular walls (lower chambers) in the heart.

The neurobiological effects of physical exercise are numerous and involve a wide range of interrelated effects on brain structure, brain function, and cognition.

Since their discovery, anabolic steroids (AAS) have been widely used as performance-enhancing drugs to improve performance in sports, to improve one's physical appearance, as self-medication to recover from injury, and as an anti-aging aid.

Central nervous system fatigue, or central fatigue, is a form of fatigue that is associated with changes in the synaptic concentration of neurotransmitters within the central nervous system (CNS; including the brain and spinal cord) which affects exercise performance and muscle function and cannot be explained by peripheral factors that affect muscle function.

4-Androstene-3,6,17-trione (4-AT; also marketed as 6-OXO or 4-etioallocholen-3,6,17-trione) is a drug or nutritional supplement that may increase the testosterone-estrogen ratio, but has no proven effect on body composition.

Exercise intolerance is a condition of inability or decreased ability to perform physical exercise at the expected level or duration of someone with a specific physical condition.

4-Hydroxytestosterone (4-OHT), also known as 4,17β-dihydroxy-4-androstene-3-one, is an anabolic steroid.