Good Nutrition Malnutrition: under, over or unbalanced consumption - - PDF document

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Test Title W.I.T.S. Personal Trainer Certification Lecture Three: Nutrition; Exercise Prescription for Weight Management; Exercise Prescription for Cardiovascular Fitness

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Good Nutrition

• Malnutrition: under, over or unbalanced

consumption of nutrients leads to disease.

• Good nutrition results from eating the

right food, with the right nutrients, in the right quantities.

• Poor nutritional choices have been linked

to CVD and cancer.

• Fitness professionals can convey

information about good nutrition, but may not prescribe detailed diets.

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The Six Essential Nutrients

• Macronutrients (needed in large

quantities):

– carbohydrate – fat – protein – water

• Micronutrients (needed in small

quantities):

– vitamins – minerals

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The Six Essential Nutrients

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Carbohydrate

• Plant-based foods (fruits, vegetables,

grains, seeds, nuts).

• Carbohydrates are broken down to

glucose.

• Body’s preferred source of energy for

physical activity and mental function.

• 1 g carbohydrate yields 4 kcal.

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Carbohydrate

• Nutrient Density: refers to the amount of

minerals, vitamins and fiber found in a carbohydrate food source.

• Glycemic index: used to describe how

quickly a food elevates the blood glucose level after ingestion.

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Carbohydrates

• Simple Carbohydrates:

– mono- and disaccharides – break down quickly to glucose – soft drinks, juice, candy, processed foods, refined grains

• Complex Carbohydrates:

– nutrient-dense polysaccharides – break down slowly to glucose – fresh whole fruits, grains, vegetables, nuts, seeds

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Fat

• Fat performs many vital functions:

– temperature regulation – protection of vital organs – distribution of vitamins A, D, E, K – energy production – formation of cell membranes – hormone production

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Fat

• Triglycerides:

– the primary storage form of fat in the body – composed of three fatty acid chains bound to a glycerol backbone – majority stored in adipose cells

• 1 g. fat yields 9 kcal
• 1 pound fat = 3500 kcal

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Fat

• Phospholipids: Important

constituents of cell membranes.

• Lipoproteins: Allow fat to travel

through the bloodstream.

• Cholesterol:

– ingested in the diet and manufactured in the body – used to form cell membranes and make hormones

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Fat

• Saturated Fat

– high intake linked to CVD

• Trans Fat

– CVD and obesity

• Unsaturated Fat
• Essential Fatty Acids

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Protein

• Amino acids combine to form proteins.
• Protein serves a variety of roles in the

body:

– provide enzymes for metabolism – enable muscle contraction – act as connective tissue – promote blood clotting – act as messengers for hormones like human growth hormone

• 1g protein yields 4 kcal.

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Protein

• 8 essential amino acids that the body cannot

make, and which must be gotten from food.

• 0.8 g of protein per kilogram of body weight is

generally adequate.

• Protein can be supplied by both meat and

vegetables.

• Vegetarians should consume complementary

proteins.

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Vitamins

• Vitamins are organic substances essential to the

normal functioning of the human body.

• Fat-soluble vitamins are A, D, E, and K.
• Water-soluble vitamins are B and C.
• Antioxidant vitamins are thought to help ward off

disease.

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Minerals

• Inorganic elements that serve a variety of

functions in the human body.

• Most consume inappropriate amounts of

calcium, iron, and sodium.

– Your body uses calcium for cardiac and skeletal muscle function. – Adequate Ca2+ promotes bone health and can prevent

• steoporosis.

– Dairy products, dark green vegetables, and some nuts are good sources of Ca2+.

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Iron

• Used by the body to make hemoglobin, the O2-

carrying protein in RBCs.

• Deficiency may lead to anemia.
• Premenopausal women should ingest 18 mg of

iron each day to offset monthly loss of RBCs.

• Good sources of iron are red meat, eggs,

spinach, legumes, and prune juice.

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Sodium

• Sodium is a mineral that many Americans over-

consume.

• Sodium is found in most processed foods.
• Sodium intake should be limited to no more than

2,300 mg a day.

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Water

• Makes up 60%+ of total body weight.
• Creates the environment in which all

metabolic processes occur.

• A person should ingest 1 to 1.5 ml of

water for each kilocalorie expended each day.

• Adequate intake for men is 3.7 L · day–1

and for women is 2.7 L · day–1.

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Dietary Assessment

• Food logs can be useful in learning about

a person’s food intake.

• A fitness professional can often provide

general information on healthy eating.

– Contact a R.D. for specific dietary considerations.

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Dietary Guidelines For Americans

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• Help people make healthy food

choices

• Focus on lowering the risk of chronic

disease and promoting health

• Encourage most people to eat fewer

calories, be more active

• Identify a variety of healthy eating

patterns

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Daily Nutritional Values

• Daily values are used in food labeling to

help consumers understand the nutritional quality of foods.

• Food labels must contain information

about total calories, fat (including saturated fat), cholesterol, sodium, carbohydrate (including dietary fiber), protein, and various vitamins and minerals.

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Nutrition Facts Label

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Lipoproteins and CVD Risk

• LDL Cholesterol: “bad” cholesterol
• linked to arterial plaque and CVD
• formed from dietary saturated fat
• HDL Cholesterol: “good” cholesterol
• helps prevent arterial plaque build-up
• manufactured in the liver
• Total Cholesterol:
• total amount of HDL and LDL
• expressed as mg·dl
• Triglycerides:
• fatty acids circulating in the blood stream

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Hydration for Exercise

• 14 to 20 oz (400-600 ml) of water 2 hr

before exercise

• 7 to 10 oz (200-300 ml) 10 to 20 min

before exercise

• 6 to 12 oz (180-350 ml) every 15 to 20 min

during exercise

• 16 to 24 oz (475-700 ml) of fluid after

exercise for every pound (0.45 kg) of weight lost

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Protein Intake for Athletes

• Aerobic athletes training intensely :

– 1.2 to 1.4 g of protein per kg of weight.

• High intensity-volume resistance training:

– 1.6 to 1.7 g per kilogram of body weight.

• Best obtained via a healthy diet rather

than amino acid supplements.

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Carbohydrate and Athletes

• Athletes should obtain 60% to 65% of their

calories from carbohydrate.

• In preparation for competition,

carbohydrate loading can be useful.

– Carbohydrate loading consists of tapering activity and ingesting large amounts of CHO in the days leading up to competition. – Rest completely on the day before competition.

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Ergogenic Aids

• Some may not be harmful but provide no athletic

edge.

• Some provide an edge but are banned.
• Some lead to health risks.
• Higher-than-RDA levels of vitamins and minerals

do not appear to provide a competitive edge.

• Creatine phosphate may enhance high-intensity

exercise performance but long-term effects are unknown.

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Female Athlete Triad

• Condition characterized by disordered

eating, amenorrhea, and osteoporosis.

• Widespread among athletes, especially

those whose sport emphasizes or requires low body weight (swimmers, gymnasts, dancers, rowers, and others).

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Etiology of Obesity

• The prevalence of obesity continues to rise.
• Causes of obesity are often not simple to

identify.

• Genetics plays a role, but lifestyle choices (e.g.,

food intake and caloric expenditure) are the most important factors.

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Prevalence of Obesity

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Energy and Caloric Balance

• Energy Balance:

– Energy consumed – energy expended

• Positive caloric balance

– Caloric intake > caloric expenditure – Leads to weight gain

• Negative caloric balance

– Caloric intake < caloric expenditure – Leads to weight loss

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Daily Caloric Need

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Resting Metabolic Rate

• Calories expended to maintain body

during resting conditions.

• Represents 60% to 70% of daily caloric

need.

• Measured using indirect calorimetry.
• Is proportional to body weight.
• Decreases with age.
• More calories are needed to sustain

muscle than are needed to sustain fat.

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Changing Lifestyle to Promote a Healthy Weight

• Reduce total calories.
• Reduce fat intake.
• Increase physical activity.
• Change unhealthy eating behaviors.

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ACSM Recommendations for Weight Management

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• Weight-loss goal of 1 to 2 lb per

week

• Weekly deficit of 3,500 to 7,000 kcal (1 lb

fat = 3,500 kcal)

• Moderate caloric restriction plus

exercise

• Limit fat intake to <30% of daily

calories

• Aim for minimum 150 minutes of

physical activity per week

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Exercise Prescription for Weight Management

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• Frequency: 5 to 7 days per week
• Intensity: initially 40-60% HRR

progress to >60% HRR

• Time: initially 30 min/day progressing

to 60 min/day

• Type: Aerobic to target large muscle

groups and facilitate caloric deficit, resistance training to help maintain fat-free mass

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Strategies for Successful Weight Loss

• Keep records.
• Plan meals and snacks.
• Solicit support.
• Set specific goals.
• Develop a reward system.
• Avoid self-defeating behaviors.
• Combine moderate caloric restriction with

aerobic exercise.

• Develop healthy eating patterns.
• Commit to lifelong maintenance.

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Gimmicks and Gadgets for Weight Loss

• Quick fixes are often inappropriate long-term

solutions to weight control.

• Saunas and sweat suits merely contribute to

dehydration.

• Electrical stimulators for the abdominal muscles
• ften use unsubstantiated claims.
• Spot reduction is a myth that certain exercises

can cause weight loss in targeted areas.

• Fad diets may lead to short-term weight loss but

rarely lead to long-term success.

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Disordered Eating Patterns

• Eating Disorder: A clinically

diagnosed condition in which unhealthy eating patterns may lead to severe declines in health, and even to death.

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Disordered Eating Patterns

• Anorexia Nervosa
• Bulimia Nervosa
• Binge-Eating Disorder
• Disordered Eating

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Signs of Disordered Eating

• Preoccupation with food, calories, and weight.
• Concerns about being or feeling fat, even when

weight is average or below average.

• Increasing self-criticism of one’s body.
• Secretly eating or stealing food
• Eating large meals, then disappearing or making

trips to the bathroom

• Consumption of large amounts of food not

consistent with the individual’s weight.

– Please review your reading for more signs.

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Strategies for Weight Gain

• Increase caloric intake by 200 to 1,000 kcal ·

day–1.

• Increase the number of healthy snacks

consumed.

• The majority of additional calories consumed

should be complex carbohydrate.

• Add resistance training to the daily routine.
• When training intensely, be sure to consume

daily 1.5 g of protein for each kilogram of body weight.

• Increase consumption of milk and fruit juices.

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Physical Activity, Exercise and CRF

• Linked to reduced risk of chronic

disease and death.

• One of the top 10 health indicators.
• As CRF increases, risk of death

decreases.

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Exercise Dose and Efgect

• Dose (amount) of exercise

prescribed is relative to desired efgect (response) for an individual.

• The dose for elite performance is

difgerent than the dose for functional health.

• Fitness professionals need to

identify clients’ goals, in order to prescribe the appropriate dose of exercise.

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Potency and Slope

• Potency: (intensity)

– Ability of the exercise to bring results. – High intensity exercise may be done less frequently than moderate.

• Slope:

– Reflects how much of an efgect results from a change in dose. – Changes can be short-term or long- term, depending on the efgect being measured.

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Maximal Efgect and Variability

• Maximal efgect

– A specific dose of exercise may be efgective for some, but not others. – Moderate exercise improves risk factors, but strenuous exercise can modify or reverse risk factors and improve VO2 max.

• Variability

– A specific dose of exercise may elicit varying efgects from one individual to another; and in one individual, depending on circumstances.

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Side Efgects

• Just like a drug, exercise may have

adverse side efgects, including increased risk of injury or death.

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Characteristics of an 
 Exercise Dose
 F.I.T.T. Principle

• Frequency: How often?
• Intensity: How hard?
• Time: How long?
• Type: What type?

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Art of Exercise Prescription

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• The proper dose of activity is dependent on

the desired efgect or goals of the individual client

• The dose of exercise needed for achieving

better health difgers from that needed to achieve peak performance

• Exercise is Medicine focuses on the need for

fitness professionals to communicate efgectively with medical personnel to realize a client’s goals

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Health Outcomes of Physical Activity: Strong Evidence

– lower risk of early death, CHD, stroke, HBP, adverse blood lipid profile. – lower risk of Type II diabetes and metabolic syndrome. – lower risk of colon and breast cancer. – prevent unwanted weight gain and promote weight loss. – improved CRF and muscular strength. – prevention of falls, reduced depression and improve cognitive function.

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Health Outcomes of Physical Activity

• Moderate to strong evidence:

– better functional health. – reduced abdominal obesity.

• Moderate evidence:

– lower risk of hip fracture. – lower risk of lung and endometrial cancer. – weight maintenance after weight loss. – increased bone density. – improved sleep quality.

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Short- and Long-Term Responses to Exercise

• Acute responses: Occur with one or

several bouts of exercise, but do not improve further.

• Rapid responses: Benefits occur

early, then plateau.

• Linear responses: Gains continue
• ver time.
• Delayed responses: Occur only after

several weeks of training.

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Short- and Long-Term Responses to Exercise

• BP and insulin sensitivity are most

responsive to exercise.

• Changes to VO2 max and HR are

intermediate.

• Serum lipid changes are delayed.

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Short- and Long-Term Responses to Exercise

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Public Health Recommendations

• Minimum of 150 to 300 minutes of

moderate-intensity exercise, or 75 to 150 minutes of vigorous- intensity exercise weekly.

• More health-related benefits can be

realized by exceeding the minimum recommendations.

• Multiple intermittent bouts daily

can accomplish minimum goals.

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Public Health Recommendations

• Resistance training of all major

muscle groups should be done on at least 2 nonconsecutive days per week.

• Benefits are gained when a

sedentary person becomes active,

• r when a moderately active person

engages in more vigorous activity.

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Guidelines for CRF Programs

• Screen participants.
• Encourage regular participation.
• Provide a variety of activities.
• Program for progression.
• warm-up, a cool-down, stretching,

and muscular endurance exercises.

• Periodically re-assess your client.

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Formulating the ExRx

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Following FITT Principle Frequency

• Moderate intensity (≥5 days per week)
• Vigorous intensity (≥3 days per week)

– Gains can be made on <3 day, but intensity would need to significantly increase, and weight-loss goals may become diffjcult to reach – For previously sedentary >4 days/wk at vigorous intensity may increase dropout

• r injury rate

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Formulating the ExRx

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Following FITT Principle Intensity

• Moderate intensity (≥5 days per week)
• Vigorous intensity (≥3 days per week)

the overall dose should be 500-1000 MET-minutes per week

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Understanding METs

• Intensity of exercise is expressed in

metabolic equivalents (METs).

• METs are a ratio of a person’s

working metabolic rate to their resting metabolic rate.

• One MET is the energy cost of

sitting quietly.

• 1 MET = 3.5 ml·kg-1·min-1

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Understanding METs

• Moderate intensity:

– Activity that noticeably elevates HR for more than 10 minutes. – 3.0-6.0 Mets are the moderate intensity equivalent of 5 to 6 on a 10 point RPE scale. – Brisk walking is considered moderate intensity.

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Understanding METs

• Vigorous intensity:

– Activity that substantially increases breathing and HR. – > 6 METs is the vigorous activity equivalent of 7 to 8 on a 10-point RPE scale. – Jogging or running are considered vigorous intensity.

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ExRx: Intensity

• Answers the question: “How hard?”
• Can be expressed as:

– Percent of VO2 max. – Percent of VO2 reserve (VO2R). – Percent of Heart Rate reserve (HRR). – Percent of max HR. – Rating of perceived exertion (RPE).

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ExRx: Duration

• Answers the question: “How many

minutes?”

• VO2 max improves with duration.
• Optimal duration depends on

intensity.

• When the duration of vigorous

exercise exceeds 30 minutes, the risk of injury increases.

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Determining Intensity: Metabolic Load

• Most direct way to determine

intensity is percent of VO2 max.

• Optimal range of percent VO2 max

for CRF is 60% to 80%.

• Measuring VO2 max is expensive

and diffjcult.

• Target heart rate (THR) is used to

approximate training intensity using estimations of VO2 max.

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THR: Direct Method

• Maximal GXT:

– intensity is gradually increased – heart rate is linear with metabolic load. – HR is monitored at each stage, and plotted on a graph against METs. – max value is reached when linear relationship discontinues. – peak value is reached when the subject can no longer continue.

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Maximal Heart Rate (MHR)

• Best calculated by GXT results.
• GXT is not always possible in the

fitness setting.

• Tanaka et. al. refined the max HR

formula to estimate maximal HR.

• MHR = 208 - (0.7 x age)

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THR: Indirect Methods

• Heart Rate Reserve (HRR)

– difgerence between resting and maximal heart rate. – % of HRR = % of VO2R – for average to high levels CRF, % HRR roughly equals % VO2 max. – HRR Formula:

• [(MHR - RHR) x 60% ]+ RHR = 60 % HRR
• [(MHR - RHR) x 80%] + RHR = 80% HRR
• values represent range of 60%-80% HRR.

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Training Threshold

• The minimal intensity necessary to

elicit a training efgect.

• For most of the population, the

training threshold is:

– 60%-80% of VO2max, HRR and VO2R – 75%-90% HRmax. – 50% - 85% HRR is optimal for CRF improvement.

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Rating of Perceived Exertion (RPE): Scale of 0-10

Extremely Easy: 0-1 Easy: 2-3 Somewhat Easy: 4-5 Somewhat Hard: 6-7 Hard: 8-9 Extremely Hard: 10

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Program Selection/Type

• Part of the FITT Principle
• Depends on client goals, need for

supervision, and other personal and environmental variables.

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Programming for Untested and Fit Populations

• As fitness levels improve, absolute

exercise intensities must be greater to maintain THR ranges.

• Fit individuals can exercise at >85%

VO2max.

• Training for competition requires

higher intensities than training for CRF.

• Performance requires increased

frequency and duration of training.

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Guidelines for Health, 
 Fitness and Performance

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Questions/Discussion?