kin 3535 exam 2

purpose of exercise prescription (ExRx)

meet individual health & physical fitness goals

FITT-VP principle

o F: Frequency (how often)

o I: Intensity (how hard)

o T: Time (duration or how long)

o T: Type (mode or what kind)

oV: Volume (total amount of exercise)

o P: Progression (exercise advancement)

Some individuals may not respond as expected

general considerations for ExRx

 Individual’s goals

 Physical fitness

 Health status

 Schedule

 Physical and social environment

 Equipment

 Individual’s preferences!!

components of exercise training session

warm up/initiation

conditioning

cool down

warm up/initiation phase

 Allows the body to adjust to the physiologic, biomechanical, and

bioenergetic demands of the exercise session.

 Light-to-moderate intensity activities specific to muscle groups that will be used during exercise.

• Improves ROM.

• the risk of injury during exercise.

 Dynamic warm-up is superior to static flexibility exercises.

 Warm-up duration may vary (typically <15min)

conditioning phase

Training exercises (e.g., aerobic, resistance, and/or sport activities), depending on the specific goals of the exercise session.

Duration: 10-60min depending on the intensity of the activity

cool down phase

 Allow body to return to near-resting levels (e.g., HR, BP) following the

exercise session.

 Low-to-moderate intensity aerobic activities. Flexibility exercises may also be performed.

 Duration: 5-10min

dose of ExRx

frequency of aerobic exercise

 Frequency (i.e., number of days per week).

 3-5 days per week for most adults.

 Multiple combinations of frequency and duration may be used to meet PA guidelines (e.g., 3 days of 50mins of aerobic exercise, or 5 days of 30mins).

 Aerobic exercise once or twice weekly at moderate-to-vigorous intensity can lead to substantial fitness/health benefits.

 Vigorous intensity exercise performed >5 days per week might increase musculoskeletal injury and is not recommended for most adults.

ACSM recommendation of frequency of aerobic exercise

• At least 3 days per week.

• For most adults, spreading the exercise sessions across 3-5 days

per week may be the most conducive strategy to reach the

recommended amount of PA.

intensity of aerobic exercise

 There is a positive dose response of health/fitness benefits that results from increasing intensity.

 Principle of overload: Exercising below a minimum intensity, or threshold, will not challenge the body sufficiently to result in changes in physiologic parameters.

 Minimum intensity varies among individuals and depends on CRF levels and other factors (e.g., age, health status, etc.).

interval training

 Interval training involves intermittent periods of intense exercise separated by periods of recovery.

 Interval training leads to similar or greater health adaptations compared with traditional endurance training.

 An effective strategy to increase total volume and/or average exercise intensity of an exercise session.

types of interval training

high intensity interval training (HITT)

sprint interval training (SIT)

resistance based

common HIIT protocols

ACSM recommendation fot intensity of aerobic exercise

Moderate (40%-59% HRR) and/or vigorous (60%-89% HRR) intensity is recommended for most adults.

methods of estimating exercise intensity

 %HRR

 %HRmax

 %VO2R

 %VO2max

 %METs

HHR method

Target HR (THR) = [(HRmax — HRrest) × % intensity desired] + HRrest

VO2R method

Target VO2R = [(VO2max− VO2rest ) × % intensity desired] + VO2rest

HR max method

Target HR = HRmax x % intensity desired

VO2 max method

Target VO2 = VO2max x % intensity desired

MET method

Target MET = [(VO2max) /3.5 mL/kg/min] × % intensity desired

other methods of estimating exercise intensity

perceived exertion

OMNI scale

talk test

all are subjective

EX of HRR method; HRrest= 70bpm, HRmax= 180bpm, desired intensity = 60% HRR

Formula: (THR) = [(HRmax — HRrest) × % intensity desired] + HRrest

HRR = 180bpm-70bpm = 110bpm

THR = [(180-70) x 0.6] + 70= 136 bpm

EX of HR.max method: HRmax = 180bom, desired intensity = 75%

THR= 0.75 x (180) = 135 bpm

objectively measured during CPET

predicted HRmax= 220-age

steps of VO2R method

select desired intensity in VO2R

calculate target VO2

convert target VO2 to workload using ACSM metabolic equations

ex of vo2r method: vo2max = 26ml, target intensity = 40%

Target VO2 = (intensity fraction)(VO2max – VO2rest) + VO2rest

 Target VO2 = (0.40)(26 – 3.5) + 3.5

 Target VO2 = (0.40)(22.5) + 3.5

 Target VO2 = 9.0 + 3.5 = 12.5 mL · kg-1 min-1

vo2max method

target vo2= vo2max x % intensit desired

the % vo2 method does not translate directly into %HRR units

MET method ex: vo2max= 38mL, intensity - 60%

Convert VO2max to MET

• 38/3.5 = 10.9 METs

Calculate Target MET

• 10.9 METs x 0.6 = 6.5 METs

MET of calisthensics (push ups, sit ups, pull ups, jumping jacks)

8.0

METS of ballet, modern or jazz, vig intensity

6.8

ACSM recommendation of time/duration of aerobic

Most adults should accumulate 30-60min/day (≥150min/wk) of moderate intensity exercise, 20-60min/day (≥75min/wk) of vigorous intensity exercise, or a combination of moderate and vigorous intensity exercise daily to attain the recommended targeted volumes of exercise.

longer durations may be needed for weight loss

PA bouts of <10min may result in health benefits in sedentary or minimaly active individuals

type of aerobic exercise

 Rhythmic, aerobic-type exercises involving large muscle groups are recommended for improving cardiorespiratory fitness.

• aerobic exercise is associated with catabolic signaling

• resistance exercise is associated with complex I, etc.

• recommended to perform aerobic exercise after resistance training

 Principle of Specificity: Physiologic adaptations to exercise are specific to the type of exercise performed.

modes of aerobic exercises

walking, jogging, swimming, running, rowing, basketball, soccer, dancing, elliptical, cyclcing, etc.

ACSM recommendation for type of aerobic exercise

Aerobic exercise performed in a continuous or intermittent manner that involves major muscle groups is recommended for most adults.

volume of aerobic exercise

Exercise Volume= Frequency x Intensity x Duration of the exercise session

 May be used to estimate the gross energy expenditure (EE) of an individual’s Ex Rx (MET-min/wk and kcal/wk)

ex of aerobic exercise volume: jogging (7METS) for 30min, 3dy/week for 70kg male

MET-min-wk: 7 METS x 30min x 3 times = 630 MET-min/week

kcal-wk-1: [(7mets x 3.5mL x 70kg) /1000] x 5 = 8.575kcal -min

8.575kcal-min x 30min x 3 times - 771.75 kcal/week

progression of aerobic exercise

• It depends on the individual’s health status, physical fitness, training responses, and program goals.

• May consist of increasing any of the components of the FITT as tolerated.

• An increase in exercise time/duration per session of 5–10 min every 1–2 wk over the first 4–6 wk of an exercise training program is reasonable for the average adult.

• After the individual has been exercising regularly for at least 1 month, volume is typically increased over the next 4–8 months.

• Progression in Ex Rx should be made gradually to minimize risks of muscle soreness, injury, excessive fatigue, and overtraining.

• Do not increase frequency, intensity, and duration in any single week. Advance volume ~10%.

• Following adjustments in Ex Rx , the individual should be monitored for any adverse effects of the increased volume.

muscular strength

the maximal amount of force that can be generated during a specific movement pattern at a specified velocity of contraction.

The muscle’s ability to exert maximal force with a single maximal effort.

hypertrophy

increase in size of a muscle

muscular endurance

the ability of the muscle groups involved a movement to sustain exercise.

The muscle’s ability to continue to perform successive repetitions against a submaximal load.

muscle power

the rate of performing work; the product of force and velocity.

The ability to exert a maximal force in as short a time as possible, as in accelerating, jumping and throwing implements

effect of resistance training on strength, hypertrophy, power, and endurance

increases

resistance training

The form of periodic exercise whereby external weights provide progressive overload to skeletal muscles in order to make them stronger and often result in hypertrophy

adaptations following resistance training

increase in hypertrophy, power & strength, neural adaptations, myofibrillar protein synthesis

small increase in mitochondrial protein and density compared to aerobic

frequency of resistance training

In untrained individuals, muscular improvements can be gained by training each muscle group at least once per week.

Rapid improvements in muscular fitness of untrained individuals are likely attributed to neural adaptations.

neural adaptations from resistance training

increase EMG = increase force

increase in rate of motor unit activation = increase in rate of force development

increase in coordination of antagonistic muscle groups = increased effectiveness of force application

increase in motor unit synchronization = increase force

increased recruitment of high threshold motor units = increase rate of force development

increase time high threshold motor units can be activated = increased time maximum force can be maintained

ACSM recommendation for frequency of resistance training

For novice trainers, each major muscle group should be trained at least 2 days per week with a minimum of 48h between training sessions for the same muscle group.

For experienced exercisers frequency is secondary to training volume, thus individuals can choose a weekly frequency per muscle group based on personal preference.

intensity of resistance training

• Intensity during resistance training refers to the magnitude of loading

(amount of weight lifted).

• Most often expressed as a percentage of 1-RM for a given exercise

or a range may be chosen (e.g., 10-15-RM).

• The range for intensity and repetitions can vary substantially

depending on the component of the muscular fitness the individual

wishes to improve.

intensity for muscle strength

Loads >60% 1-RM are recommended.

Untrained:

• Various intensities (40%-85% 1-RM) can lead to improvements in muscular strength.

• Maximal gains with loads >60% 1- RM. •

Trained:

• Higher intensity is recommended (≥80% 1-RM)

intensity for muscle hypertrophy

• Previous research suggested that high-load resistance training (>60% 1-RM) was necessary for muscle hypertrophy.

• However, a large body of evidence demonstrates that load is not the main determinant of muscle hypertrophy.

• Performing sets to volitional failure has been shown to result in muscle hypertrophy, even with loads as little as 30% of 1-RM.

• Repetition range: 6-20-RM

intensity for muscle endurancce

• Light to moderate loads have been shown to be effective at increasing muscular endurance.

• No consensus on optimal range of repetitions.

r • Lighter loads may be coupled with higher repetitions (≥15-25reps)

intensity for muscle power

• 1-3 sets per exercise of 3 to 6 repetitions at 30-60% 1-RM per set.

• Intent is to move resistance with maximal velocity.

explosive resistance training where concentric phase is performed at maximal speed while eccentric phase is controlled

acsm recommendation for intensity of resistance training

For novices, 60-70% 1-RM, performed for 8-12 repetitions are recommended to improve muscular fitness.

For experienced exercisers, a wide range of intensities and repetitions are effective depending on the specific muscular fitness goals.

types of resistance training equipment

free weights, body weight, resistance bands, resistance training machines

types of resistance training exercises

Multijoint exercises (e.g., push-ups, bench press, shoulder press, lat pull-downs, pull-ups, bent-over rows, leg press, deadlifts, etc.)

Single-joint exercises (e.g., bicep curls, triceps extensions, leg extensions, leg curls, etc.)

Core exercises (e.g., curl-ups, medicine balls throws, planks etc.)

muscle actions in resistance training

conentric: shortening

eccentric; lengthening

isometric: no change in muscle length and joint angle

isokinetic: speed is constant throughout entire movement

ACSM recommendation for types of resistance training

Multijoint exercises affecting more than one muscle group and

targeting agonist antagonist muscle groups are recommended

for all adults.

• Single-joint and core exercises may also be included in a

resistance training program, typically after performing

multijoint exercise(s) for that particular muscle group.

• A variety of exercise equipment and/or body weight can be

used to perform these exercises

rest intervals for muscular strength

Gains in muscular strength can be achieved with short rest intervals (60s per set).

When time is not a factor, a longer rest interval (>2min) may allow higher overall training volume, leading to greater improvements in muscular fitness.

A reasonable rest interval between sets is 2-3min

volume of resistance training

Volume: sets x repetitions x resistance

• Example: 3 sets x 8 reps per set x 75lbs per repetition = 1800lbs

Dose-response relationship between the number of sets per muscle group and the levels of hypertrophy and strength gains.

Training options:

• 1 exercise using multiple sets

• 1 or more sets of a combination of 2+ exercises

progression of resistance training

May be performed in several ways:

• Increase the load by ~5-10% for the next training session.

• Perform more repetitions with the same load.

• Increase the number of sets per muscle group per week.

• Increase the number of days per week each muscle group is trained.

Maintenance can be achieved by as little as 1 resistance training session per week.

case study: compare muscle related adaptations between 2 8week programs: 1 = increasing load while rep is constant and 2= increaseing rep while keeping load constant

results showed the thickness of the rectus femoris increased by 2.8mm in reps group

dynamic strength increased by 2.0kg in load group

resistance training technique

The exercises should be executed using correct form and technique:

• Deliberate and controlled

• Full ROM of the joint

• Proper breathing techniques (i.e., exhalation during the concentric

phase and inhalation during the eccentric phase).

flexibility

The ability to move through a joint’s ROM.

• Immediate improvements following stretching exercises.

• Chronic improvements after ~3-4 weeks of regular stretching 2-3 times per week.

stretching exercises

• Stretching exercises are encouraged for increasing ROM.

• However, stretching exercises may temporarily undermine exercise performance, muscle strength, and power.

stretching types

ballistic methods of bouncing stretches

dynamic or slow movement stretching

static stretching

proprioceptive neuromuscular facilitation

ballistic methods or bouncing stretches

use momentum of the moving body segment to produce the stretch

dynamic or slow movement stretching

involves a gradual transition from one body position to another and a progressive increase in reach and range of motion as the movement is repeated several times.

• It mimics the intended exercise or sport activity that will follow.

• Increases core temperature, which increases neuromuscular conduction and compliance, and enzymatic activity

• Dynamic stretching >30s may facilitate performance

static stretching

involves slowly stretching a muscle/tendon group and holding the position for a period of time (~10-30s). Static stretches can be active or passive.

two types: active and passive

active stretching

Involves holding the stretched position using the strength of the muscle as is common in many forms of yoga.

passive stretching

Involves assuming a position while holding a limb or other part of the body with or without the assistance of a partner or device (e.g., elastic band)

proprioceptive neuromuscular facilitation

methods take several forms but typically involve an isometric contraction of the selected muscle/tendon group followed by a static stretching of the same group (i.e., contract-relax).

flexibilty exercise recommendations

-Flexibility exercises are recommended to improve joint-specific ROM

and to improve performance.

-Dynamic stretches are encouraged before any exercise bout and

may also be used to improve performance.

-Static, ballistic, and/or PNF stretching should be performed on their

own, as part of a specific program to increase ROM, and not

preceding any exercise activity.

acsm recommendation for flexibility exercises

frequency: 2-3days/wk with daily being most effective

intensity: Stretch to the point of feeling tightness or slight discomfort

time:

• Holding a static stretch for 10-30s is recommended for most adults.

• In older individuals, holding a stretch for 30-60s may confer greater benefits.

• For PNF stretching, passive stretch for 10s followed by a 3-6s light-tomoderate contraction followed by a 30s assisted stretch is desirable

type:

• A series of flexibility exercises for each of the major muscle-tendon units is recommended.

• Static flexibility (i.e., active or passive), dynamic flexibility, ballistic flexibility, and PNF are effective.

normal body temp

36.6-37C

Skin temperature is closer to that of the environment.

Internal body temperature remains relatively constant.

how do we maintain body temp in the cold?

increase rate of body’s heat production

decrease body’s rate of heat loss

body begins shivering (involuntary)

body moves to generate heat (byproduct)

how do we maintain our body temp in hot env

increase heat dissipation

humans as homeotherms (similar temp)

Humans maintain constant body core temperatures.

O2 transport, cellular metabolism, muscle contraction are NOT impaired in hot and cold environments if the internal temperature is maintained.

However, abnormal body temperature may have catastrophic effects on the organism.

• cell damage with an internal body temp >41C,; heat stroke and brain damaeg can occur

• slow cellular metabolism with an internal body temp <34-35C; unsconciousness and cardiac arrhythmias

heat gain

metabolic heat

environmental heat (radiation + conduction + convection)

metabolic heat production

rate of transformation of chemical energy into heat

thermal balance

heat gain = heat loss

heat loss

radiation, conduction, convection, evaporation

under normal, resting conditions in a thermoneutral env, most of the heat is removed by radiation

radiation

loss or gain of heat in the form of electromagnetic waves

conduction

transfer of heat from body to an object by direct contact

convection

conduction of heat to or from air or water

evaporation

conversion of liquid to gas

liquid to vapor

how is body temp regulated

hypothalamus

regulation of body temp: heat

receptors from skin and core send info to CNS to hypothalamus

response is vasodilation and sweating

regulation of body temp: cold

receptors from skin and core

response is vasoconstricition, shivering, catecholamine release, thyroxin release

heat dissipation during exercise in a cool env

evaporation heat loss increases

convective loss increases slightly

radiative loss is constant

heat dissipation during exercise: hot env

sweat rate increase proportional to temperature of env and rate of heat production

exercise in hot environemnts

Shifts in thermal balance can result in heat illness.

• Metabolic heat is transferred from the active muscles to the blood

increasing the body’s core temperature.

• The increase in body temperature activates mechanisms of heat

loss (e.g., ↑ blood flow to the skin, ↑ sweat secretion) to dissipate

heat to the environment.

• Hyperthermia (i.e., elevated internal body temperature) may

develop if metabolic heat > heat loss.

measurement of heat stress

Wet Bulb Globe Temperature (WBGT) is a measure of the heat stress in direct sunlight, which takes into account: temperature, humidity, wind speed, sun angle and cloud cover (solar radiation). This differs from the heat index, which takes into consideration temperature and humidity and is calculated for shady areas

dehydration

The higher the body water deficit, the higher the increase in

physiologic strain for a given exercise.

• Dehydration may result in further increases in core temperature

(0.1oC to 0.2oC with each 1% of dehydration).

• Impaired mechanisms of heat loss (e.g., decreased sweating rate

and cutaneous blood flow).

• May negatively affect exercise endurance performance

consequences of dehydration: endurance exercise

Dehydration by 3.5% before endurance exercise leads to:

• Greater HR response

• Exaggerated Tre response

• Reduced performance

consequences of dehydration: anaerobic exercise

Dehydration before anaerobic exercise leads to:

• A reduction in total work

• A reduced buffer capacity

• Full recovery of work occurs with rehydration

assessment of hydration status

morning weight, urine, and thirst perception

counteracting dehydration

0.5L of fluid is recommended for each pound of body weight lost

fluid replacement

Fluid intake in short duration exercise does not influence body temperature

After ~45 min, limiting fluids causes a rise in Tre

Fatigue occurs around 40oC regardless of hydration status

type of fluid in fluid replacement

• Overdrinking water can lead to exercise-associated hyponatremia.

• Hyponatremia can lead to nausea, vomiting, headache, extremity

edema, and other severe symptoms.

• More common in long duration physical activities.

• Can be prevented by a hydration plan.

exertional heat illnesses

heatstroke, heat exhaustion, syncope, heat cramps