Download Body Responses - St. Raymond High School for Boys

Nutrients, Physical Activity, & Body Responses
I.
Intro: nutrition & phys’l activity: the body demands all 3 – yielding nutrients as fuel & protein to
form lean tissues mass.
A “couch-potato” lifestyle ranks w/smoking & obesity for developing great health risks. Even
just 30 min of phys’l activity brings many health benefits.2/3 of US population are irregularly or
completely inactive!
II.
Essentials of Training
A.
4 Components of Fitness
1.
2.
3.
4.
Flexibility: capacity of the joints. to move thru full range of motion; to bend & recover w/o injury.
ability of msl to work against resistance.
Msl Endurance: msl contracting w/o getting exhausted.
Cardiovascular (CV) endurance: ability of the heart to sustain effort over a period of time.
B.
Body Response to Activity: People shape their body by what they choose or choose NOT to
do! Msl cells & tissue respond to an:
Overload: msls are taxed beyond their accustomed load; may be by an increase in frequency,
duration, or intensity. Our msls respond by:
Hypertrophy: an increase in msl size & strength vs. :
Atrophy: decrease in msl size & strength from lack of use.
Anabolic: growth of msl tissue/cells
Androgenic: increase of msl strength
Catabolic: breakdown of msl tissue/cells
1.
2.
3.
4.
5.
6.
So that #3 doesn’t happen, different msl groups should be worked on different days.
C.
Aerobic Activity & the Heart
1.
Aerobic Activity: (aac) is any activity that requires the heart & lungs to work harder than normal,
for a sustained time period (20 min or>), delivering O2 to the tissue & therefore strengthening them
(especially the heart).
- aac is essential to fat loss & maintaining wt. loss.
- Wt. lifting, although considered anaerobic, can be aerobic, depending upon the person’s
intensity.
III.
Glucose for Fuel Activity: glucose stored as msl glycogen, is a major fuel for phys’l activity; as
activity continues, hormones signal the liver & fat cells to mobilize their nutrients.
A.
Glucose Use & Storage: the liver & msl store glucose as glycogen; the liver can also make
glycogen from other nutrients (h.o.9-7). Msl glycogen is only used for msl activity.Liver glycogen
is released into the bloodstream for use by the whole body.
Total glycogen stores affects an athlete’s endurance; both glycogen intake & storage increase
w/increasing CHO intake & phys’l activity.
B.
Activity, Intensity, Glucose, & Glycogen Use
1.
During moderate aerobic activity msls extract nrg both from glucose & F.A. when they’re present
w/O2; in this way, a little glucose helps burn a lot of fat.
Intense activity is different. The heart & lungs can provide only so much O2 & therefore fat can’t
be used b/c O2 is required for its breakdown. Msl must begin to rely more on glucose from their
limited glycogen store (anaerobic).
Anaerobic breakdown of glucose produces Lactic acid -> msl cramps, “burn”, & fatigue. A short
rest to replenish O2 supplies is all that’s needed to breakdown lactic acid for nrg or convert it to
glucose.
C.
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Fig 10-3
Activity, Duration, Glucose use, & Glycogen stores: a person exercising moderately for >
20min,begins to use < glucose & more fat for fuel, but gluc. use continues ‘till msl & liver glycogen
stores are depleted. To postpone exhaustion & increase endurance:
1.
2.
3.
4.
Eat a high CHO diet.
Take a glucose drink during activity.
Eat a CHO rich food after activity ( CHO loading -> enables msls to store > amts of glycogen)
Train msls to max glycogen stores.
***
Highly trained msls use < glucose & > fat than untrained, therefore, glycogen lasts longer.
IV.
Using Fat to Fuel Activity
A.
Adipose tissue is more important as fuel for activity than is fat in the diet; fat can fuel hrs. of
activity w/o running out (glycogen is limited).
Msls begin to use f.a. early in their activity from 2 sources:
1. w/in working msl & fat deposits such as under the skin.
2. Areas that have the most fat to spare “donate” the >est amts*
[* this is why “spot reducing” doesn’t work; eg. Msls do not own the fat around them – f.a.released
into the blood is used by all msl. Eg. Fat fold measurements in a tennis player’s arm are the same
even though one arm is more developed]
B.
Intensity & Duration Affects Fat Use
1.
2.
Intensity: fat can be broken down for nrg in only ONE way – aerobic metabolism.
Duration: fat cells begin to shrink after the 1st 20min of aerobic activity, as they empty out their fat
stores.
C.
Degree of Training: repeated aerobic activity stimulates msl to develop more fat burning nzymes.
V.
Protein & Amino Acid for Building Muscle & Fuel
A.
B.
Protein for Building Muscle: msl building actually occurs during rest, after phys’l activity, when
msl speed up their rate rate of prot synthesis
Protein Used as fuel: the body speeds up its use of a.a. for nrg during phys’l activity. Prot
contribute 10% to the total fuel used by the body, @ activity or rest. Factors that regulate how much
prot is used during activity involve:
1. Diet: a CHO rich diet spares prot from being used for fuel.
2. Intensity/Duration of Activity
3. Degree of Training: the better the trained athlete, the < prot used.
C.
The amt of protein intake depends upon lifestyle, activity, etc. A bodybuilder will need to take in
much > amt of protein than say a tennis player.
VI.
Improve Body Composition
A.
Trimming Down: phys’l activity will:




***
B.
Increase nrg use
Increase resting metabolic rate (slightly)
Regulate appetite
Help control stress induced over – or under eating
For phys’l activity to promote fat loss, it must involve use of the skeletal msls. Passive activity
DOES NOT increase nrg use or build msl. Research shows that moderate activity burns more fat
than high intensity b/c more fat than CHO is used.
However, w/a given time period, more total nrg will be used @higher intensities & so more TOTAL
nrg from fat will be used. Total nrg spent, as well as total nrg from fat, is > w/hi intensity activity.
_________
Table 10-3
Building Up: NO machine or activity will do anything to build up msl unless the present demands
overload. NO “wt-gain” supplements will build up msl w/o phys’l activity. Hi intensity exercise can
strengthen msl, add lean msl tissue, & increase body wt.