•

underlying principles in the field of exercise science

•

provides the foundations that your body must make in response to the physical stress incurred during a single bout of exercise

•

1. Homeostasis

•

the tendency of the body to maintain a stable internal environment for cells by narrowly regulating critical variables

•

pH (acid/base balance)

•

oxygen tension

•

blood glucose concentration

•

body temperature

•

any disruption to optimal homeostatic conditions will elicit multiple regulatory responses by the body in an attempt to bring disrupted variables back to normal

•

when you ascend a high altitude, due to the low oxygen pressure in the inspired air, oxygen levels in your body drop below desired levels

•

as a result, your nervous, endocrine, cardiovascular, and respiratory systems make adjustments in an attempt to compensate for this disruption in homeostasis

•

engaging in physical exercise is a very powerful and stressful disruptor of normal homeostasis

•

the more intense, the greater the disruption

•

muscles and blood become more acidic

•

blood oxygen and glucose levels must be regulated

•

body temperature increases

•

tissues that must respond

•

brain

•

lungs and repository system

•

muscles

•

kidney

•

liver

•

cardiovascular system

•

heart pumps more forcefully

•

blood vessels must dilate

•

nervous and endocrine systems regulate

•

circulating hormones cause changes

•

blood is directed away from the less critical tissues such as the stomach

•

insure that the muscles are receiving adequate blood flow

•

the homeostatic overload principle

•

if you habitually overload a system, it will respond and adapt

•

stress imposed illicits an immediate response referred to as an acute response

•

if you exercise three to five times per week over months, the body will adjust long term to absorb the repeated stress of regular exercise, a process called chronic adaptation

•

examples

•

during acute exercise, the body reacts by producing mitochondrial biogenisis in skeletal muscle in order for the muscles to oxidate

•

after weeks of being repeatedly activated, chronic adaptations are made in the pathways responsible for mitochondrial biogenisis thereby increasing their numbers, which leads to an increase in the oxidative capacity of skeletal muscle

•

specificity principle

•

only the system or body part repeatedly stressed will adapt to chronic overload

•

when you do bench presses for weeks and months, only the chest muscles recruited will show improvements in strength

•

cardiovascular system is only marginally recruited during strength training

•

will show no long-term adaptations

•

principle of reversibility

•

whereas overloading will result in training adaptations, inactivity will result in a return to baseline

•

a common way to express this is "use it or lose it"

•

principle of individuality

•

while the physiological responses to a particular stimulus are largely predictable, the precise responses and adaptations will vary among individuals

•

we can predict the direction of adaptations, but he magnitude will likely differ

•

mostly due to genetics of the subjects in question

•

the response of identical twins would be more uniform than two unrelated individuals