EXS PHYS Final exam

In Aerobic Training the focus should be on...

-Enhancing central circulation's capacity to deliver O2 (i.e. improved cardiac output) -Developing active muscle's ability to consume O2 (i.e. improved a-VO2 difference)

Talk Test

-Exercise intensity may be set on the basis of the "individual's" ability to talk while exercising -Ability to talk while exercising denotes a minimal improvement response in aerobic conditioning -Higher than "ability to talk" level will give greater improvement in aerobic fitness level

Responses to Anaerobic Training

-Increased intramuscular levels of ATP, PC, and glycogen -Increased quantity and activity of glycolytic enzymes (e.g. PFK - rate limiting enzyme in glycolysis) -Increased ability to generate ability to generate higher levels of blood lactate -Increased tolerance to muscle fatigue

Karvonen Method

-One of most common ways of setting up a target (or threshold stimulus) heart rate is: HRthreshold = (Max HR*-Rest HR).60 + Rest HR E.g. HRthreshold = (190-70).60 + 70 = (120).60 + 70 = 72 + 70 = 142 bpm Note: Max HR may be obtain by: 220-Age or from recorded maximal exercise effort

Responses to Aerobic Training: Other adaptations

-Reduction in body fat and gain in lean muscle mass -More responsive heat regulatory system -Sweat more -Sweat sooner -Improved psychological profile -Reduction of anxiety levels -Reduction in depression -Better self-esteem

Factors that Improve Heat Tolerance #3 age

. Age -Not a major issue with heat tolerance in most physically matured individuals -Children •Have a lower sweat rate •Higher core temperature response to exercise •Have large number of sweat glands •Different sweat composition than adults •Recommendations -Exercise at a lower intensity -Hydrate appropriately Allow more time to acclimatize

Factors that Improve Heat Tolerance #4 gender

. Gender -Sweating response •Women have more heat-activated sweat glands •Men sweat sooner and more than women •Women have lessened chance of dehydration compared to men -Cooling rate •Women can cool faster due to larger surface area

Six factors impact muscle mass development and maintenance.

1. Endocrine Influences 2. Genetics 3. Physical Activity 4. Environment factors 5. Nutritional Status 6. Nervous system activation

Factors that Improve Heat Tolerance #1 acclimatization

1.Acclimatization -Physiologic adaptation that improves tolerance to heat -2 to 4 hours of daily exposure to hot environment allows adjustment to heat within 10 days -Adjustments made include: •Improved skin blood flow •Improved blood distribution (helps maintain BP) •Sweat sooner (lowered sweat threshold) •Sweat more •Greater distribution of sweat over body surface (more involvement of sweat glands •Decreased loss of salt in sweat Benefits of acclimatization can be lost within 2-3 week

Factors influencing aerobic conditioning

1.Initial level of cardiorespiratory fitness -The lower the initial fitness level, the greater the improvement 2.Frequency of training -Aerobic benefits occur primarily with exercise 3 days/week for at least 6 weeks 3.Duration of training -20 to 30 minutes of continuous, moderately paced exercise per session results in aerobic improvement 4.Intensity of training -Most critical factor in aerobic conditioning -Achieving a HR of 130-140 bpm (college age person) or Exercising at 50-55% of VO2 max or Exercising at 70% HRmax

General Training Principles

1.Overload Principle -Application of "above normal" effort 2.Specificity Principle - Also known as the S.A.I.D. (Specific adaptations to imposed demands) principle -Application of particular efforts related to the sport movement and metabolic needs -E.g. strength and power activities are incorporated for baseball players E.g. cardiovascular and muscular endurance activities are incorporated for swimmers 3.Individual Differences Principle -Fitness level at start of training may differ -Must adjust to individual needs and capacities 4.Reversibility Principle -Detraining occurs rapidly when a person stops exercising E.g. 20 days of bed rest can result in: - 20-25% decrease in aerobic capacity (this approximates 1% loss per day)

Summary: Part 1

1.Resistance training and strength development objectives: fitness and health enhancement, strength and physique competitions, physical rehabilitation, enhanced sports performance, knowledge of muscle structure and function. 2.Common methods to measure muscular strength: tensiometry, dynamometry, 1-RM testing with weights, computer-assisted force, and work-output determinations. 3.Improperly performed resistance training with excessive back arch create shearing forces that can trigger low back pain. 4.Substantial physiologic and performance specificity require valid tests to determine success in specific physical tasks and occupations. 5.On an absolute basis, men outperform women on strength tests because of their larger muscle mass.

Summary: Part 2

1.Six factors—genetics, exercise, nutritional, hormonal, environmental, and neural—interact to regulate skeletal muscle mass and strength development. 2.Muscle fiber size, fiber type, and anatomic-lever arrangement of bone and muscle determine strength. 3.CNS neural influences that activate prime movers in a specific movement greatly impact strength expression. 4.Two factors—improved capacity for neuromuscular activation and significant alterations in a muscle fiber's contractile elements—increase strength with resistance training. 5.Muscle overload hypertrophies muscle fibers. 6.Muscle fiber hypertrophy structurally changes fast-twitch fiber contractile components and increases anaerobic energy stores.

Summary: Part 1 body comp

1.Total body fat consists of essential fat and storage fat. 2.Essential fat contains fat in bone marrow, nerve tissue, and organs; does not represent a viable energy reserve. 3.Storage fat accumulates in adipose tissue beneath the skin and deeper visceral depots. 4.Storage fat averages 12% of body weight for young adult men and 15% of body weight for women. 5.True gender differences exist for essential fat—3% body weight for men and 12% body weight for women. 6.Greater sex-specific essential fat for women likely relates to childbearing and hormonal functions. 7.Reducing body fat below essential fat level can compromise good health and optimal physiologic capacity. 8.Menstrual dysfunction occurs among female athletes who train hard, incur an energy deficit, and maintain low body fat levels. 9.Potential interacting causes of menstrual dysfunction: psychological stress of consistent training and competition, hormonal balance, energy and nutrient intake, body composition.

In Anaerobic Training the focus should be on...

1.Training ATP-PC system -Involves highly intense efforts of 5-10 seconds (e.g. 100 yd dash) -Exercise bouts should be repetitive -Should involve muscles that are performing the sport activity 2.Training Glycolytic (lactic acid) system -Involves highly intense exercise bouts up to 1 min (e.g. 200 to 400 yd run) -Exercise bouts should be repetitive with 3-5 min recovery periods -Should involve muscles that are performing the sport activity

Six-Phase Sequence for DOMS Following Unaccustomed Activities

1.Unaccustomed exercise using eccentric muscle actions (downhill running, slowly lowering weights) 2. High muscle forces damage sarcolemma causing release of cytosolic enzymes and myoglobin 3. Damage to muscle contractile myofibrils and non contractile structures 4. Metabolites (e.g. calcium) accumulate to abnormal levels in the muscle cell to produce more cell damage and reduce force capacity 5. Delayed-onset muscle soreness considered to result from inflammation, tenderness, pain 6. The inflammation process begins; the muscle cell heals; the adaptive process makes the muscle more resistant to damage from subsequent exercise

Summary: Part 1 (cont.) again

12.Plyometric training (repeated standing long jumps, hops, vertical jumps, box jumps) incorporates the inherent stretch recoil within the neuromuscular system to develop specific muscular power. 13.Body weight loading with suspension training activates agonists and antagonist muscles along the kinetic chain. 14.Periodization divides a distinct period (macrocycle) of resistance training into smaller training mesocycles and weekly microcycles. 15.Compartmentalization of training minimizes staleness and overtraining to maximize peak performance timed for competition. 16.Resistance training for competitive athletes optimizes muscular strength, power, hypertrophy.

Summary: Part 1 (cont.) and again

17.Resistance-training goals for older adults: modestly improve muscular strength and endurance, maintain muscle and bone mass, enhance overall health and fitness. 18.Resistance training goal for specific sports: develop maximum force-generating capacity at a speed that closely mimics the performance. 19.Concurrent training to improve muscular strength and aerobic capacity inhibits strength improvement compared with training only for muscular strength.

Summary: Part 1 (cont.)

6.Regardless of gender, human skeletal muscle theoretically generates maximum of 16 to 30 N maximum force per cm2 muscle cross-section. 7.Muscles become stronger with overload training by increasing load or speed or combining increases in load and speed. 8.Strength gains occur when overload represents 60% to 80% of muscle maximum force-generating capacity. 9.Closely supervised concentric resistance training for children does not produce adverse effects on bone or muscle. 10.Three major exercise systems develop muscular strength: DCER training, isometric training, isokinetic training. 11.Isokinetic training generates maximum force throughout full ROM at different limb movement velocities.

Summary: Part 2 (cont.)

7.Muscle enlargement involves increased protein synthesis within contractile elements and proliferation of cells that thicken and strengthen connective tissue harness. 8.Resistance training does not change cellular component adaptations to enhance aerobic energy transfer. 9.Women and men improve strength and muscle size at about same relative percentage. 10.Resistance training generally contributes little to enhanced cardiovascular aerobic fitness. 11.Resistance training without dietary constraint does not reduce body fat because of its relatively low-energy cost. 12.CRT using lower resistance and higher repetitions enhances muscle-training benefits of resistance exercise with CV and calorie-burning benefits of continuous PA. 13.Eccentric muscle actions produce more DOMS compared with concentric-only and isometric exercise. 14.Inflammatory response in DOMS includes muscle tears and connective tissue damage.

Factors that Improve Heat Tolerance #body fat level

Body Fat Level -The greater the amount of body fat, the greater potential for heat problems

Responses to Aerobic Training: Cardiovascular adaptations

Cardiovascular Adaptations: -Increased heart size (increase in left ventricular cavity size + thickend walls - known as eccentric hypertrophy) -Increased plasma volume (up to 20%) -Increased stroke volume -Decreased HR at rest and submaximal exercise -Increased maximal cardiac output -Increased O2 extraction by skeletal muscle -Increased blood flow to active muscles -Increased capillarization in trained muscles -Decrease Systolic and Diastolic blood pressure -May decline 6-10 mmHg

Exercise Performance

Dependent on 3 major energy systems: -ATP-PC System -Lactic Acid [glycolytic] System -Aerobic [oxidative] System

Factors that Improve Heat Tolerance #2 exercise training

Exercise Training -Increases sweating response (sweat sooner) -Greater plasma volume -Also, other responses noted in acclimatized individual

Responses to Aerobic Training: Metabolic adaptations

Metabolic Adaptations: -Increase in mitochondrial size and # -Increase in aerobic enzymes (e.g. enzymes involved in Kreb's cycle, ETC, Beta-oxidation) -Improvement in ability to utilized fats, particularly the triglycerides stored in the active muscles -Improved ability to use and store CHO -Larger slow-twitch fibers

Circuit Resistance Training (CRT): Increased Energy Expenditure

Modifying standard resistance training by de-emphasizing heavy overload and increasing caloric expenditure and workout volume Beginners can work 2´ through circuit from A to B; after several wk, they progress 3´ through; finally, increase number of circuit revolutions up to 6, depending on number of stations. Intermediate level adds several stations; participants proceed 3´ to 6 ´ through circuit A to C. Build progression into each circuit by increasing stations (A to D) and/or load, repetitions, duration.

Eccentric/Concentric Strength Testing

One-Repetition Maximum (1-RM) •Initial weight close to but below max capacity •Weight progressively added on subsequent attempts until achieving max lift capacity -Weight increments usually range between 1 to 5 kg depending on muscle group tested •Rest intervals = 1 to 5 min

Important Resistance Resistance Training Effects on Muscle Cellular Adaptations

Overload training enlarges individual muscle fibers with subsequent muscle growth.

Responses to Aerobic Training: Pulmonary adaptations

Pulmonary Adaptations: -Increased Max VO2 -Increased Max minute ventilation (MMV) -Enhanced ventilatory muscle endurance -Decreased ventilatory equivalent for oxygen, i.e. VE ÷ VO2 -This means that the lungs can take O2 out of the air more easily -This will be specific to the muscles that were trained, i.e. training with leg muscles (cycling) will ↓ VE/VO2 only when doing leg exercise; same idea for arms -All of static lung volumes will increase except for tidal volume

Resistance Training Neural and Muscle Adaptations

Relative roles of neural and muscular adaptations in strength improvement with resistance training •Neural adaptations predominate in early phase of training. •Hypertrophy-induced adaptations place upper limit on longer-term training improvements.

Mean Body Temperature

Tbody = (0.6 x Tcore) + (0.4 x Tskin) This equation gives the average body temperature at any given time such that: - 60% is accounted for by the core - 40% is accounted for by the skin

Gender Differences in Muscular Strength

Two strength testing approaches determine gender differences: 1.Absolute muscle strength (total force exerted) ●Men have greater strength in all muscle groups tested. ●Women score about 50% lower for upper-body strength and 30% lower for leg strength. 2.Relative muscle strength (force exerted relative to weight, FFM or MCSA) ●Skeletal muscle fibers in vitro generate 16 to 30 N max force per cm2 muscle MCSA regardless of gender. -In vivo force-output capacity varies depending on bony lever arrangement and muscle architecture

Environmental Stress During Exercise in the Heat

•2 circulatory adjustments: -Must increase O2 delivery to muscles to sustain energy metabolism -Must increase blood flow to skin to dissipate heat; however, this takes away blood flow to muscle

General Rule for acclimation

•Acclimation to altitude takes time and must be progressive -Much like scuba diving at different depths

Exercise Capacity at Altitude

•Aerobic capacity -Decreases with an increase in altitude •Approximately 1.5 to 3.5% decrease in VO2 max per each 1,000 feet increase above 5,000 ft altitude •Cardiovascular function -Decrease in maximal cardiac output •Primarily due to ↓ stroke volume Does not improve with stay at altitude

Dynamic Constant External Resistance (DCER) Training

•Alters external resistance to movement with a lever arm, irregularly shaped metal cam, air, hydraulics, or pulley to match increases and decreases in force capacity related to joint angle throughout ROM -Lifting and lowering phases with each rep using weight plates or machines that feature different applications of muscle overload •Major type: DCER, Progressive Resistance Exercise (PRE) -Variations of PRE alter number of sets, reps, including frequency and relatively intensity all prove successful.

Muscle Soreness and Stiffness

•Any six factors singly or combined produce delayed-onset muscle soreness (DOMS): 1.Minute tears in muscle tissue or damage to its contractile components 2.Osmotic pressure changes that cause fluid retention 3.Muscle spasms 4.Overstretching and tearing of portions of the muscle's connective tissue harness 5.Acute inflammation 6.Alteration in cell mechanism for calcium regulation 7.Combination of above factors

Practical Recommendations for Initiating Resistance Training

•Avoid max lifts in beginning stages of training. •Use lighter resistance and more repetitions at start of training. •After 2 to 3 wks of training, decrease repetitions to between 6 and 8. •Add more resistance after reaching target repetition number. •Training sequence proceeds from larger to smaller muscle groups to avoid fatigue of smaller muscles.

Exercise in the Cold

•Body loses heat approximately 2- 4 times faster in water compared to air at the same temperature •The colder the temperature, the greater the O2 consumption -Due to additional cost of shivering to stay warm •Body fat is protective against the cold -Swimmers generally have more subcutaneous fat than other athletes not subjected to colder temps.

Cold Air and Exercise

•Can you freeze your lungs during exercise? -Not likely, incoming cold air is warmed up by the time it gets to bronchi •Significant water and heat loss can occur via the respiratory tract (expired air) -Must continue to remain hydrated during prolonged exercise in the cold •Only lose about 20% of body's heat through the head -Must still keep it covered in cold temp Also should wear light layers of clothes while exercising

Cardiovascular Response to Exercise in the Heat

•Cardiac Output -Stays the same during submaximal effort •Heart rate increases •Stroke volume decreases -Decreases at maximal exercise •Heart rate increases but not enough to offset decrease in stroke volume

Muscle Fiber Hyperplasia

•Chronic skeletal muscle overload in various animal species develops new muscle fibers from normally dormant satellite cells between the basement layer and plasma membrane or by longitudinal splitting. -With longitudinal splitting, a relatively large muscle fiber splits into two or more smaller individual daughter cells through lateral budding. •These fibers function more efficiently than the large single fiber from where they originated.

Training Comparison of Traditional Bench Press

•Comparison of traditional bench press movement versus a ballistic bench "throw" to maximize power. •Results were unequivocal— during bench press, deceleration begins at 60%of bar position relative to total concentric movement distance (orange line). •In contrast, velocity during bench throw (yellow line) continues to increase throughout ROM and remains higher at all bar positions following movement. -Translates into greater-average plyometric force, average power, and peak power output

Resistance Training Guidelines

•Competitive athletes -Focus on optimizing strength, power, muscular hypertrophy with high-intensity 1 to 6 RM. •Middle-aged and older adults -Focus on maintenance and possible increase of muscle and bone mass and muscular strength and endurance to enhance overall health. •Cardiac patients -Focus on strength maintenance to minimize musculoskeletal injuries.

Muscle Action Types

•Concentric action: In dynamic activities where muscle shortens and produces tension through the range of motion •Eccentric action: When external resistance exceeds muscle force and muscle lengthens as tension develops •Isometric action: When a muscle generates force and attempts to shorten but cannot overcome external resistance •Dynamic constant external resistance (DCER): External weight or resistance remains constant throughout movement

Core Temperature response to Exercise

•Core temperature will increase as exercise intensity increases -Trained and acclimatized individual has greater tolerance to increased body heat

Storage and Essential Fat

•Essential fat -Fat in heart, lungs, liver, spleen, kidneys, intestines, muscles, and lipid-rich tissues of CNS and bone marrow; includes sex-specific fat in female (important for childbearing and hormonal functioning) •Normal physiologic functioning requires essential fat •Storage fat -Fat packed primarily in adipose tissue -Includes visceral fat that protect various internal organs and subcutaneous fat

Rebound Jumping Technique in Plyometric Training

•Examples of plyometric drills 1.Box jump 2.Cone hop 3.Hurdle hop 4.Long box jump

Consequences of Dehydration

•Fluid loss equivalent to 1% of body mass -Increases core temperature •Fluid loss equivalent to 5% of body mass -Increases core temperature and heart rate -Decreases sweating rate, VO2 max, and aerobic capacity

Water Loss in the Heat

•For an acclimatized person: -Sweat loss peaks at ~ 3 L/hr during intense exercise in the heat •This would average out to be 12 L (or 26 lbs) in a day •A high school wrestler could lose 9-13% of their weight prior to weigh-in (primarily due to water restriction and excessive sweating from exercise) -Difficult to regain this amount lost within a 20-hr period; only about 8 lbs. -Places wrestler in a dehydrated state

What regulates body temperature?

•Hypothalamus -Contains the central coordinating center for temperature regulation -Receives input from: •Thermal receptors in the skin provide information •Temperature of the blood (as it flows by hypothalamus) provides information -Anterior hypothalamus - stimulates heat loss -Posterior hypothalamus - stimulates heat conservation

Physiologic Adjustments to Altitude Immediate

•Immediate: -Hyperventilation -Fluid loss (due to respiratory fluid loss to cold, dry air) -Increased cardiac output •Primarily due to ↑ heart rate; stroke volume remains the same

Resistance Training for Children

•Incomplete skeletal development raises concern about potential for bone/joint injury with heavy muscular overload. -Limited evidence indicates that closely supervised resistance training programs with concentric-only muscle actions with high repetitions and low resistance improve children's muscular strength without adverse effect on bone or muscle.

Factors affecting heat loss

•Increased ambient temperature -Reduces effectiveness of heat loss particularly by radiation, conduction, and convection •Increased relative humidity -Reduces effectiveness of heat loss by evaporation •Decreased wind velocity -Reduces both convective and evaporative effectiveness •Reduced surface exposed to environment -Reduces effectiveness of all heat loss mechanisms

Power-Velocity Relationship

•Inverted U relationship between muscle's max power output and speed of limb movement during concentric muscle action. •Peak power increases with increasing velocity to a peak velocity region; then max power output decreases from reduced max force at faster movement speeds. •Each muscle group has optimum movement speed to produce max power.

Plyometric Training: Explosive Jump Training

•Involves rapid stretching followed by shortening of muscle group during dynamic movement •Basic principle for all jumping and other plyometric exercises absorbs shock with arms or legs and then immediately contracts muscles -Plyometrics avoid disadvantage of having to decelerate a mass in the latter part of ROM during a fast movement; this provides for max power production.

Acclimatization to Altitude

•It takes approximately 2 weeks to adapt to an altitude of 2300 meters -For each additional 610 m in altitude, it takes an additional week (up to 4572 meters)

Body Weight-Loaded Training

•Known as closed-kinetic chain exercise. •Suspension training introduces the added component of instability to further challenge trunk and back muscle neuromuscular control.

Core Training

•Known as lumbar stabilization, core strengthening, dynamic stabilization, neutral spine control, trunk stabilization, abdominal strength, core "pillar" training, core functional strength training -Core region includes 29 pairs of muscles that hold trunk steady, in addition to balancing and stabilizing bony structures of spine, pelvis, thorax, and other areas activated during most movements. -Without adequate "strength and balance," totality of these spine-frame structures would become mechanically unstable.

Fat-Free Body Mass and Lean Body Mass

•Lean body mass (LBM) -Contains small percentage of non-sex-specific essential fat equivalent to approximately 4% to 7%of body mass •Fat-free body mass (FFM) -Body mass devoid of all extractable fat •LBM in men and minimal body mass in women -Chiefly essential fat (plus sex-specific fat for women), muscle, water, bone

Connective Tissue and Bone Adaptations

•Ligaments, tendons, and bone strengthen as muscle strength and size increase. •Connective tissue proliferates around individual muscle fibers. -Thickens and strengthens muscle connective tissue structures. -The adaptations from resistance training help protect joints and muscles from injury and justify resistance training for preventive and rehabilitative strategies.

Physiologic Adjustments to Altitude long term

•Long-term: -Hyperventilation -Increased C.O. and HR -Increased pH (more alkaline) -Increased O2-carrying capacity •Occurs due to ↓ plasma volume & ↑ RBC's -Enhanced cellular adaptations •↑ concentration of capillaries in muscle •↑ mitochondria •↑ 2,3- DPG (improves release of O2 from RBC to muscle)

Minimal Leanness Standards

•Lower limit beyond where body mass cannot decrease further without lowering FFM, which impairs health or alters normal function: -Men: 3% body fat -Women: 12% body fat •Criteria to identify underweight adult female: -Body mass lower than minimal body mass calculated from skeletal measurements -Body mass ≤20th percentile by stature Body fat ≤17% EX: minimal body fat in starvation

Cardiovascular Need vs Temperature Regulation Need

•Maintenance of blood flow to muscle takes precedence over regulation of temperature in the body -Can lead to increase heat build-up in core, hence the problem of heat illness during exercise

Isometric (Static) Training

•Max voluntary isometric actions produce greater gains in isometric strength than submax actions. •Duration of muscle activation directly relates to increases in isometric strength. •One daily isometric action does not increase isometric strength as effectively as repeated actions. •Isometric training does not provide a consistent stimulus for muscular hypertrophy. •Gains in isometric strength occur predominantly at the joint angle used during training. •Limitations of Isometrics 1.Difficulty in monitoring intensity and results •Benefits of Isometrics 1.Effectively improves strength of particular muscle or group of muscles when isometric force covers four or five joint angles throughout ROM 2.Effective in orthopedic and physical therapy applications that isolate strengthening movements during rehabilitation

Resistance Training Changes Muscle Fiber Type Composition

•Metabolic characteristics of specific fibers and fiber subdivisions undergo modification within 4 to 8 wk after starting resistance training. -Occur despite dramatic changes in inherent muscle fiber types with chronic resistance training. -Decrease in percentage of type IIb and increase in type IIa fibers denote prominent and rapid resistance training adaptations.

Computer-Assisted Electromechanical and Isokinetic Determinations

•Microprocessor technology integrated with strength equipment quantifies muscular force and power during muscular movements. -Isokinetic dynamometer: electromechanical accommodating resistance instrument with a speed- controlling mechanism, accelerates to a preset, constant velocity with applied force regardless of the force exerted on the movement arm

Acclimatization to the Cold

•More difficult to adapt to cold than heat •With Acclimatization: -Increase heat production does accompany body heat loss -Individuals regulate at a lower core temp -Protective response to frostbite in periphery (blood flow enhanced to hands and feet)

Isokinetic Resistance Training

•Muscle action performed at constant angular limb velocity. •Isokinetic device controls movement velocity. •Muscles exert max forces throughout ROM while shortening at specific velocities. •Max force throughout ROM optimizes strength development. •Concentric-only actions minimize potential for muscle and joint injury and pain. -Progressive decline in concentric peak torque output with increasing angular velocity of knee extensor muscles in two different groups in sports training and fiber composition. -For movement at 180º·s−1, power athletes achieved higher torque per kg body mass than endurance runners.

Muscle Remodeling: Can Fiber Type Be Changed?

•Muscle cell remodeling involves satellite cell incorporation into existing muscle fibers. −Muscle represents dynamic tissue whose cell populations do not remain fixed throughout life. −Muscle fibers undergo regeneration and remodeling and alter their phenotypic profile to meet diverse functional training demands.

Specificity of Strength-Training Response

•Muscle strengthened and enlarged by DCER does not demonstrate equal improvement in force capacity measured isometrically or isokinetically. -Important to train muscle(s) in movements that mimic movements during performance. Focus should be on force, velocity, and power requirements rather than isolated muscle actions. •Resistance training specificity and strength improvement blend adaptations in two areas: 1.Muscle fiber and connective tissue harness of specific muscle or muscles. 2.Neural organization and excitability of motor units that power discrete voluntary movement patterns.

Favorable Response of Middle-Aged and Elderly Individuals

•Muscles and tendons respond favorably to chronic changes in loading independent of age or gender. •Data from five older men before (orange) and after (yellow) 12-wk heavy resistance training.

Training Muscles to Become Stronger

•Muscles strengthen when trained near max force generating capacity. •Overload intensity (tension on muscle), not type of exercise, determines overload and strength improvements. •Progressive resistance weight training, isometric training, and isokinetic training represent three common exercise systems to train muscles to become stronger.

Resistance-Training Systems

•Muscular strength can develop by five different but interrelated systems: 1.Isometric training 2.Dynamic constant external resistance training 3.Variable resistance training 4.Isokinetic training 5.Plyometric training

Measurement of Muscular Strength

•Muscular strength: Max muscle force, tension, torque •Isometric muscle testing: Muscle force measured at specific joint angle -Cable tensiometer -Dynamometers -Computer-assisted devices

Resistance Training Neural Adaptations

•Neural adaptations predominate in early-phase training. •With training, untrained person recruits more motor units to achieve max muscle action. -Increased motor unit firing synchronization causes more motor units to fire simultaneously.

Does training at altitude improve aerobic performance at sea level?

•No •The benefit of training at altitude is for improving performance at altitude!

Thermoregulation and the Body's Limits

•Normal body temperature fluctuates throughout the day: -Can tolerate a drop in deep body temperature of 18oF (10oC) -Can only tolerate an increase of 9oF (5oC) • •Oral temperature is 1oF (.56oC) less than rectal temperature -With exercise, this difference increases since air circulates via the oral and nasal passages

Water Replacement

•On average: -Consume 250 ml (8.5 oz) of fluid every 10-15 minutes during a prolonged workout or competition of moderate intensity •If working at a high level, should consume fluid at higher amounts every 10 minutes •Electrolyte replacement can be helpful •Helps maintain plasma [sodium], sustains thirst drive, promotes retention of ingested fluid, and more rapidly restores lost plasma volume

Strength Training Principles and Guidelines

•Overload (Intensity) -Muscles respond to intensity of overload rather than overload mode. -Amount of overload reflects percentage of 1-RM of nonfatigued muscle or muscle group. -Minimal intensity for muscular overload occurs between 60% and 70% 1-RM. •Three approaches apply muscular overload: 1.Increase load or resistance 2.Increase repetition number 3.Increase speed of muscle action •Force-Velocity Relationship -Absolute or peak force generated in movement depends on speed of muscle lengthening and shortening. -Muscles shorten (and lengthen) at different max velocities depending on the load placed on them. -Max shortening velocity decreases as load increases. -Muscle force-generating capacity rapidly declines with increased shortening velocity.

Leanness, Regular Physical Activity, and Menstrual Irregularity

•Physically active women who participate in "low weight" or "body appearance" sports increase likelihood for one of three medical maladies: 1.Delayed onset of menstruation 2.Oligomenorrhea 3.Amenorrhea •Menstrual dysfunction results from: -Changes in pituitary gland's normal pulsatile secretion of luteinizing hormone, regulated by gonadotropin-releasing hormone from hypothalamus •LBM-to-body fat ratio -13% to 17% body fat represents a minimum range associated with regular menstrual function

Periodization (cont.)

•Preparation phase -Emphasizes modest strength development with high-volume, low-intensity workouts •First transition phase -Emphasizes strength development with workouts of moderate volume and moderate intensity •Competition phase -Selective strength development with low-volume, high-intensity workouts plus short periods of interval training that emphasize sports-specific activities •Second transition phase (active recovery) -Emphasizes recreational activities and low-intensity workouts that incorporate different activity modes

Heat Loss Mechanisms

•Radiation - emission of electromagnetic heat waves •Conduction - direct transfer of heat through a liquid, solid, or gas (direct contact) •Convection - transfer of heat via air currents over surface of skin •Evaporation - vaporization of water from respiratory passages or surface of skin (2-4 million sweat glands)

Body Composition Adaptations to Resistance Training

•Small decreases occur in body fat with minimal increases in total body mass and FFM. •Largest FFM increases amount to about 3 kg over 10 wks. -Same results for men and women •No resistance training system proves superior for changing body composition.

Strength Testing Considerations

•Standardize instructions prior to testing •Ensure uniformity of warm-up duration/intensity •Provide adequate practice prior to testing to minimize "learning" effects of improved strength •Ensure consistency among subjects in angle of limb measurement and/or body position on test device •Predetermine min trial number (repetitions) to establish a valid criterion strength score •Select tests with high test score reproducibility •Recognize individual differences in body size and composition when evaluating strength scores

Resistance Training Muscle Adaptations

•Three factors explain strength capacity: 1.Muscle cross-section 2.Fiber type 3.Mechanical arrangement of muscle and bone •Muscle fiber hypertrophy •Increase in muscle tension (force) with training is primary stimulus to initiate muscle hypertrophy. •Hypertrophy occurs from: 1.Increased contractile proteins 2.Increased number and size of myofibrils per fiber 3.Increased connective, tendinous, and ligamentous tissues 4.Increased enzymes and nutrients

Load-Repetition Relationship

•Total work accomplished by muscle action depends on load (resistance). •Area from 60% to100% 1-RM represents strength training zone. -Training stimulus optimizes improvement. *Relationship between max repetitions to failure and load at 20% to 100% 1-RM*

Direct Assessment of Body Composition

•Two direct methods 1.Chemical dissection 2.Physical dissection Various tissues in adult males and females based on physical dissection of cadavers as a percentage of total body mass (kg)

Assessing Body Size and Composition

•Two general approaches determine fat and fat-free components: 1.Direct measurement by chemical analysis or dissection 2.Indirect estimation by hydrostatic weighing, anthropometric measurements, and body stature and mass

Estimating 1-RM Strength Using Submax Reps to Fatigue

•Untrained 1-RM kg = 1.554 X 7-to 10-RM weight (kg) - 5.181 • Trained 1-RM kg = 1.172 X 7-to 10-RM weight (kg) - 7.704

Periodization

•Varies training intensity and volume to ensure peak performance coincides with major competition •Subdivides specific resistance-training period into a macrocycle and smaller mesocycles, separated into weekly microcycles -Progressively decreases training volume and increases intensity as duration progresses to maximize newly acquired strength/power improvements

Cardiovascular Adaptations to Resistance Training

•Weightlifters and bodybuilders with hypertension can exhibit these four characteristics: 1.Essential hypertension without identifiable cause 2.Experience chronic overtraining syndrome 3.Use anabolic steroids or other performance enhancing drugs 4.Possess undesirable level of body fat or hypertension risks established for the general population

Mechanisms of temperature regulation

•When it is hot: (need for heat loss) -There is vasodilation of subcutaneous blood vessels; more sweating (↑ heat loss) -There is decreased muscle activity; decreased secretion of thyroxine and epinephrine (↓ heat production) • •When it is cold: (need for heat retention) -There is vasoconstriction of skin blood vessels; also curling up to stay warm (↓ heat loss) -Shivering and increased voluntary muscle activity; increased secretion of thyroxine and epinephrine (↑ heat production)

Exercise at Altitude

•With an increase in altitude, there is a decrease in PO2 -This just means that O2 molecules are not as close together •For example: At sea level, the PO2 is 100 mmHg; but at the top of Mt. Everest (8,848 m), it is 28 mmHg so there is only 58% O2 saturation of arterial blood There is still 20.9% O2 in the air at altitude

Responses of Men and Women to DCER

•Women achieve higher percentage strength improvement than men, although considerable overlap exists between sex comparisons. •Relative equality in trainability between women and men with short-duration resistance training.

Max Force-Velocity Relationship for Shortening and Lengthening

●Rapid shortening velocities (d·s−1) generate least max force. ●Shortening velocity is zero (max isometric force) when curve crosses y axis. ●Force-generating capacity increases to highest as muscle lengthens at rapid velocities.