the decrease in muscle size due to immobilization or complete lack of exercise
delayed-onset muscle soreness (DOMS)
muscle soreness felt a day or two after eccentric exercise
fiber hyperplasia
muscle size increase occurring from an increase in the number of muscle fibers achieved through fiber splitting
fiber hypertrophy
muscle size increase occurring from an increased protein synthesis resulting in the increased number of myofibrils and actin/myosin filaments
muscular endurance
the muscle’s capacity to sustain repeated activation
muscular power
the muscle’s ability to exert strength for a measure of time
muscular strength
the muscle’s maximum generated force
adenosine triphosphatase (ATPase)
enzyme which is used to breakdown ATP thereby releasing its contained energy.
adenosine triphosphate (ATP)
high-energy molecular compound which provides energy for the body’s activity such as muscle movement. It resides in the body’s cells and is derived from food bond energy
aerobic metabolism
generation of energy in the presence of oxygen
ATP-PCr system
a system which is used by cells to replenish ATP supplies. The molecule, PCr, is acted upon by an enzyme which releases a bonded phosphorous (P) plus energy. An ADP molecule uses this P and energy to form ATP.
basal metabolic rate (BMR)
an older measure of the resting baseline energy consumption by the body to sustain basic life support in the absence of voluntary muscle movement. This measurement was performed after 8 hours of sleep. BMR has been replaced by RMR which yields essentially
electron transport chain
series of chemical reactions which converts the hydrogen ion generated by glycolysis and the Krebs cycle into water and produces energy for oxidative phosphorylation.
fatigue
general sensation of tiredness with decrease in muscular performance
gluconeogenesis
the conversion of fat or protein into glucose
glycogenesis
the conversion of glucose into glycogen
glycogenolysis
the conversion of glycogen into glucose
glycolysis
the breakdown of glucose into pyruvic acid
glycolytic system
a system which produces energy through glycolysis.
Krebs' cycle
a series of chemical reactions which involves the complete oxidation of acetyl CoA and produces ATP with the byproducts of water and carbon dioxide.
lactate threshold (LT)
point during exercise where lactate starts to accumulate above the resting level. This occurs because lactate clearance in insufficient relative to lactate generation
maximal oxygen uptake (VO2max)
the maximum capacity of oxygen consumption by the body
oxidative system
most complex energy system for generating high energy yields from the oxidation of fuels
phosphocreatine (PCr)
energy rich compound which is used in the fast generation of ATP during initial muscular activity
