Understanding the Biology of Fatigue in Body Building

Most of modern researchers have differed withthe lungs to decimal absorption of the vital gas during
previous believe that fatigue is consequent to anthe finishing distance of a race while also putting
accumulation of lactic acid in the muscles. Actuallymaximal output of energy from muscles faster than
lactate stops muscles' fatigue by keeping them fullythe muscle can convert through metabolism, ends up
responsive to various nerve signals.collapsing at the end or close to the end of a race.
Muscles are kept agile and strong by constantYet after a few minutes in which he or she lowers
provision of oxygen and nutrients. Disturbance of ionthe breathing rate and thereby improves oxygen
homeostasis and demands placed on the muscles isabsorption and places no further energy demands on
what determines performance during an exercisethe muscles, recovers within minutes.
during intense workouts. Each and every contractionThe brain also adjusts automatically the power
of muscles constitutes an action that essentiallyoutput of muscles to ensure that even in intense
activates voltage sensors in the muscles and therebyworkouts, the energy demands placed on muscles is
releases Ca2+ ions from sarcoplasmic reticulumboth safe and well catered for by replacement
contained within muscle fibers. Such an action triggersmechanisms. In this, the brain acts as a central
ion changes like Na influx during depolarization phaseregulator of muscle performance. In body building, the
or K influx during repolarization phase.neural calculations try to regulate and thereby balance
This explains why muscle fatigue develops graduallythe energy demands of exercises, the level of strain,
with exercise intensity and length. CL- ions diffuseduration of the workout during which there is a
into the sarcoplasm to aid the repolarization phase.continuous exertion of energy and also the
When a body builder places demanding contractions inmetabolism rate and state in the body builder's
the muscles, ion pumps responsible for maintainingmuscle system.
homeostasis or simply balance of these ions areThis means that muscle fatigue is not just caused by
automatically inactivated thereby triggering ionicmechanical failure the muscles (previously referred to
disturbances. The net result is cellular membrane'sas peripheral fatigue). Rather, fatigue develops once
depolarization coming out to the body builder asthe central regulator determines that available
muscle weakness. This general weakness and fragilityresources in energy, including that produced in
of muscles is what we can accurately identify ascontinuous metabolism is far by exceeded by
muscle fatigue.expended energy and any further demands of
Intense and prolonged exercises usually bring about aenergy fro the muscles given the particular intensity
severe imbalance of ions in muscles and sometimes aof exercise, could drive muscles into danger limits.
total collapse of body homeostasis. These are whatFatigue is not a bad thing at all when conceived in this
cause athletes to collapse after the final lap, havinglight. Actually it is just a signal that indicates certain
put maximal demands to muscle contraction potentialbrain signals to the muscles. By using fatigue as an
in the last lap.indicator of exhaustion and calling the body builder to
But fatigue is quickened and perhaps triggered byquit, the brain thereby protects the brain
insufficient supply of oxygen and nutrients in thehomeostasis and also ensures that regular exercises
muscle tissues. This explains why a short distancedo not go as far as exhausting emergency reserves
athlete who totally depletes oxygen supply and ridesof energy.