Nutrients, Physical Activity, & Body Responses I. Intro: nutrition & phys’l activity: the body demands all 3 nrg – 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.Flexibility: capacity of the jts. to move thru full range of motion; to bend & recover w/o injury. 2.Strength: ability of msl to work against resistance. 3.Msl Endurance: msl contracting w/o getting exhausted. 4.Cardiovascular (CV) endurance: ability of heart & lungs 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: 1.Overload: msls are taxed beyond their accustomed load; may be by an increase in frequency, duration, or intensity. Our msls respond by: a)Hypertrophy: an increase in msl size & strength vs. : b)Atrophy: decrease in msl size & strength from lack of use. c)Anabolic: growth of msl tissue/cells d)Androgenic: increase of msl strength e)Catabolic: breakdown of msl tissue/cells

So that “c” 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. 1.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.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.Eat a high CHO diet. 2.Take a glucose drink during activity. 3.Eat a CHO rich food after activity ( CHO loading - > enables msls to store > amts of glycogen) 4.Train msls to max glycogen stores. ***Highly trained msls use 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.Intensity: fat can be broken down for nrg in only ONE way – aerobic metabolism. 2.Duration: fat cells begin to shrink after the 1 st 20min of aerobic activity, as they empty out their fat stores. Degree of Training: repeated aerobic activity stimulates msl to develop more fat burning enzymes.

V. Protein & Amino Acid for Building Muscle & Fuel A.Protein for Building Muscle: msl building actually occurs during rest, after phys’l activity, when msl speed up their rate of prot synthesis B.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 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: 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 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

B. 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 End For Exam