Define Muscular Strength, Power and Endurance

-         Muscular strength- max amount of weight a muscle or muscle group can lift

-         Muscular power- strength with speed component- how fast you can move that weight across distance (F*D/speed)

-         Muscular endurance- max number of reps you can lift weight

How is strength, power and endurance measured?

-         Strength- 1 RM- max weight we can lift one time

-         Power- specific to sport- isokinetic device- can control speed

-         Endurance- depends on muscle group trying to access – pushups, crunches, etc.

How do you increase power?

-         Cannot increase very effectively- Increase strength without losing speed- train fibers to be more life fast twitch

Individuality

training must be specific to individual to genetic makeup of person

Specificity

as specific to sport or activity training for

Progressive overload

gradually increase stress on system

Periodization

system from 70s- divide season into 4-5 macro phases- organized way to make you peak- systematic approach to training

Hard/Easy

alternate hard days of training with easy days of training- rest days are equally important

Free weights

-         Adv: working all muscles including stabilizing muscles- balance- more functional-

-         Disadv: can cheat with them, not as safe, need spotter

Variable Resistance

-         Adv: safe, weight/force applied to muscle varies according to joint angle- always lifting 100% of what you can lift at that angle

-         Disadv: expensive

Electric Stim

-         Adv: artificial way of applying an electrical stimulus to have contraction and relaxation to muscle group- reduces strength lost when injured or immobilized

-         Disadv: have to go to lab to get it done

Isokinetic

-         Adv: can vary load and vary speed at which muscle group exercises at, control angle muscle is exercising at

-         Disadv: very expensive, takes up a lot of room

# of sets, % 1 RM and reps for strength training program

-         1 set, 60-80% of 1 RM, and 6-12 reps

In the first few weeks of training how does strength increase without hypertrophy?

-         neural

How many weeks after training starts does hypertrophy contribute to strength gains?

-         10 weeks

What are the neural adaptations that occur with strength training?

-         Recruit more motor units, increased synchronization of firing, increased frequency of stimulation, decreased autogenic inhibition (Golgi tendon isn’t activated as much and that senses stretch, antagonist muscle isn’t activated as much so muscles can pull more forcibly on bone)

What are the muscular adaptations that occur with strength training?        

-         Hypertrophy- increase in cross sectional size of muscle

-         Hyperplasia- increase in number of muscle fibers

What is transient and chronic hypertrophy?

-         Transient- temporary (comes and goes)- acute fluid accumulation- fluids moving from plasma into interstitial space of muscle

-         Chronic- changes like change in cross sectional fiber as result of training- chronic changes

What variables are manipulated for interval training?  What are general rules for interval training?  Why is it important?

-         Intensity, duration of interval, duration of rest, number of sets, number of repetitions

-         Shorter the exercise interval the more reps, duration depends on event

-         Look at 130-150 bpm under age of 30

-         Subtract 30 from age, subtract difference from 130 and 150 to determine bpm range before starting back up

-         Training energy systems required for short bouts of exercise (ATP-PC system and  anaerobic glycolytic system)

What happens with cessation of training?

-         Atrophy- decrease in cross sectional size of muscle- decrease in strength

According to Armstrong, what occurs physiologically with DOMS?

-         Structural damage, impaired calcium homeostasis, death of tissue (necrosis), accumulation of irritants, increase of macrophage activity

What are the strategies to prevent DOMS?

-         Start out easy (don’t overdo it), limit eccentric contractions (do a lot of damage),

Eccentric

Risk factors for heat exposure

- prior heat exposure past few days

- fitness level

- body surface area

- skin rash

- highly motivated person

- use of ephedra

- not acclimated to temperature

What environmental conditions change as a result of altitude?

At what altitude do we start to feel the effects of altitude?

What happens to respiration at altitude and why? What is respiratory alkalosis?

- increase in tidal volume, increase in rate- happens because chemoreceptors sense lower atmospheric PO2

- pH incrases bc rate and depth of breathing increases

What happens to the diffusion gradient of O2 at altitude?

What happens to the diffusion gradient of O2 at altitude?

- shifts up and left

- greater % O2 bound to hemoglobin

How is the effect of an acute exposure to altitude on the CV system?  After the acute exposure what is the next CV adaptation?

What are the metabolic responses to acute exposure to altitude?

What’s the lactate paradox?

-         exercising at higher VO2 max, you should have higher lactate levels but actually you have lower levels

At what atmospheric PO2, does VO2 max begin to be lowered when compared to sea level VO2 max? 

-         131mmhg

At  an elevation of 5,000ft, why is VO2 lower?  At > 5000 ft what causes VO2 to be lowered?  Low Atmospheric PO2:  reduced PO2 pressure gradient

-         Diffusion gradient is 75% lower

-         Diffusion gradient and max cardiac output is lower

What is the percent decline in VO2 for every 1,000 ft increase in elevation above 5,000 ft? 

What is the effect of altitude on endurance performance?  Are there sport performances that improve at altitude?

-         Decreases endurance performance

-         Increases power, sprint, or jump events

Why does the RBC count increase with long term altitude exposure?

-         Kidney secretes erythropoietin --> increase in RBCs

Why doesn’t living and training at altitude increase performance at sea level?

-         You are not able to train as hard at altitude, training impaired

What is the concept of living high and training low and why does it work?

Train hard at sea level and live at altitude to get all benefits

What are the strategies for optimizing performance in an altitude condition?

-         Get in compete and get out (limited exposure to altitude) OR go 9-14 days before and acclimatize then compete

What are the symptoms of acute altitude sickness and how can we avoid them?

-         Lightheaded, dizziness, nausea, blurred vision, breathing interruptions, sleeping disturbances

-         Go up slowly, use supplemental oxygen

What is high altitude pulmonary edema, its cause, symptoms and treatment?

-         Caused by vasoconstriction induced blood clot

-         Difficulty breathing, nausea, coughing, fatigued, blue lips

-         Supplemental oxygen and go to lower elevation

What is high altitude cerebral edema, its cause, symptoms, and treament?

- Headaches, change in mental status, ataxia, coma

- supplemental oxygen and go to lower elevation

Conduction

transfer heat through direct contact

Convection

-         heat transferred as air current or water current

Evaporation

heat lost through sweat becoming a vapor

Radiation

-         heat transferred as a result of infrared rays

How much does body temp fluctuate?

-         Can be between 97 and 100 degrees F

What is the primary way we lose heat at rest and during exercise?

-         Radiation- 60% rest

-         Evaporation- 80% exercise

How much faster do we lose heat in water that is the same air temperature?

What are the 6 factors that affect the effectiveness of heat exchange between an individual and the environment?

-         Humidity, clothing worn, air movement, degree of sunlight, heat acclimation, thermal gradient

How does the body decrease body temp when we are to hot /cold?

-         Hyperthermia- hypothalamus senses it goes up too much and it stimulates sympathetic nervous system- stimulates sweat reaction (increase in sweat)- SNS stimulates smooth muscle cells in arterials in skin (vasodilation)

-         Hypothermia- hypothalamus stimulates SNS- stimulates arterials to vasoconstrict- non shivering thermogenesis- thyroid gland secretes thyroxin to increase metabolic rate-  shivering

How sensitive are the central thermoreceptors?

-         Sensitive to a 100^th of a degree

Explain the CV response to exercise?  What is this phenomenon called?  

-         Cardiovascular drift- HR increases, SV decreases

What are the metabolic responses to exercising in the heat?

-         Increase O2 consumption, increase rate at which we use glycogen, LA increased

Why do trained athletes & acclimatized individuals have more dilute sweat (sweat with less Na, Cl) and an increased blood volume?

-         Increased alderstone level (causes sodium retention), anti-diuretic hormone (cause to loose less water)

When the environmental temp is higher than the body’s temp, what is the ONLY way for the body to give off heat?

-         evaporation

What does the WBGT measure and what is the primary variable in the WBGT?

-         Wet bulb globe temp measures air temp, evaporative ability in environment, radiant heat

-         Wet globe- measures environment evaporative ability

At what WBGT should a person not exercise or exercise in air conditioning?

-         82.4 degrees F

What are the 3 stages of heat illnesses, their symptoms and how should we treat them?

-         Heat cramps- painful cramping of large muscle groups

o  Move to cooler location, administer fluids and/or saline

-         Heat exhaustion- rapid heart rate, lightheadedness, nausea, vomiting, dizziness (caused bc CV system cannot keep up)

o  Move to cooler environment, administer fluids and/or saline, raise feet

-         Heat stroke- hypothalamus is no longer functioning, sweating stopped, mental status changes, belligerent, confusion, loss of consciousness

o  Fan to cool, seek immediate medical attention, wrap in cool wet sheets

What are the strategies for reducing the incidence of heat illnesses?

-         Pay attention to WBGT, adequate hydration, exercise in early morning or evening, light clothing, light colored, material that promotes evaporation, wear hat, know symptoms of heat illness

What is one common symptom that should alert you that a heat illness is impending?

-         Throbbing of head

How much H2O and at what frequency should you drink to prevent heat illnesses?

-         Every 10-15 minutes, 5-10 oz.

What are the effects of Acclimation?

-         CV effect-  CV drift- increase in Blood volume (2 type of hormones- aldosterone (sodium retention), ADH (not urinating as much)

-         Mechanism with sweat- days later- sweat earlier, sweat is more dilute

What are the procedures for Acclimation and how long does it take to acclimate?

-         9- 14 days, exercise for about an hour at relative low intensity

What are the initial and long-term effects of acclimation?

-         CV changes happen within 3 days sweating adaptation

What are the ways in which the body produces heat in a cold weather situation?

-         Hypothalamus senses temp going down, Vasocontrict arterioles in skin to preserve core temp,  (non-shivering thermogenesis)- sns stimulates thyroid gland to produce thyroxine to increase metabolic rate, increase heat production, shivering (4 fold increase in heat production)

What are the factors that affect body heat loss?

-         body composition (more muscle and subcutaneous fat-  better able to insulate), Surface area to mass ratio, amount of clothing, huddle (get into a ball – decrease S.A)

How much faster do we lose heat by convection in the H20 vs Air of the same °F?

-         26 times

When all heat loss mechanism are considered how much faster does the body lose heat in cold H20?

-         4 fold increase

At what core temp, does the hypothalamus lose its ability to warm the body?

-         94.1 degrees F

What are the physiological responses to cold exposure?

-         Skeletal muscle responses, decreased velocity and strength of contraction, use glucose at increased rate

-         When glucose levels down, shivering stops

-         Cardiovascularly-  SA node slows firing rate down, can get cold enough to stop firing and cardiac arrest occurs