Transcript Kin 110 HC Lecture 8

Kin 110
Lecture 10
Ch. 11 Fitness and Sport
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Fitness and Sport
• Activity and Nutrition are necessary
together
– good nutrition is essential for
performance and
– activity is essential for weight control
and a healthy body composition
• adequate fluid and carbohydrate
intake are needed to perform
• Physical Fitness - ability to do
moderate to vigorous activity
without undue fatigue
• The type of Fuel used to sustain
physical activity is affected by
– Fitness level
– intensity of activity
– diet
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Benefits of Exercise
• Only about 15% of adults practice
moderate to vigorous physical
activity on a regular basis
• Fig 11-1 - Benefits
• Improve overall Fitness
• Skill - agility, balance, coordination,
reaction time
• Health - endurance, body
composition, muscular and skeletal
fitness
• Reduced risk for heart disease
– heart muscle and circulation
– reduce other risk factors
– BP, TG, lipoproteins
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Benefits of Exercise
• Prevents and treats obesity
– caloric use
– stimulates fat burning and mobilization
– Maintain lean body mass
• Prevents and controls diabetes
– Increases glucose uptake in absence of
insulin
– Contributes to weight balance
• Osteoporosis
• Reduce infections
• Enhances psychological health
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Designing a Program
• Kinesiology 143
• (PAR-Q)
– over 35 speak with a physician before
drastically increasing activity
• Phase 1
• incorporate 30 minutes of moderate
activity into your daily routine
– Walk, take stairs, house cleaning,
gardening
– Effects are cumulative - so they can be
broken up into 10 min sections
• develop habits and use of body
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Basic Fitness Program
• Phase Two
• increase goal to 30 min of more
vigorous activity 3-5 days per week
– Fig 11-2
• include resistance exercise
– 2-3 times per week
• Warm-up
– slow jog, flexibility (2-3 per week)
• workout
– 65-85 % of Heart Rate Max
• heart rate max = 220 - age
• cool down
– slow jog, flexibility
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FITTE Formula
• Frequency, Intensity, Time, Type and
Enjoyment
• F - 3-5 times per week
• I - 65-85% max HR
– 4-6 range on RPE scale p 380
• T - 20-40 minutes
• T - any aerobic activity, repetitive use of
large muscle groups
– Running, swimming, cycling, circuit
training
• E - make sure you pick activities that you
enjoy
• Progression - important to start slowly but
also challenge your body to continue to
adapt by increasing one component (FIT)
at a time
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Metabolism
• All chemical reactions that occur in
the body
– release of energy from foods
– conversion of substances
– preparation of excretions
• Metabolic pathway
– sequence of chemical reactions
• Anabolic - building
• Catabolic - breakdown
– digestion
– energy release from carbohydrates and
lipids forming CO2 + H2O
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Energy Sources for Muscle
• Table 11.1 - energy sources
• Adenosine Tri-phosphate (ATP)
– energy currency for cells
– Fig p 381
• ion pumping, enzyme activity,
muscle contraction
• Solar energy from Sun trapped
by plants and stored as chemical
energy
• ADP + Pi + energy => ATP
– ATP stores can sustain muscle for
2-4 seconds
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Maintaining ATP
• Breakdown of PhosphoCreatine,
Carbohydrates, Fats, and
Protein maintain ATP
• ATP breakdown products
activate the splitting of PCr
– Phosphocreatine
• sustains ATP for about 10
seconds of maximal activity
• fastest most powerful activities
use this system to replace a
majority of ATP
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Carbohydrates
• Blood glucose and Muscle
Glycogen
• Glycolysis
– catabolism of glucose for ATP
• First Phase - very rapid
– low yield ( 2 ATP / glucose)
– Supports activities lasting that can
be maximal for 30 sec. to 2 min.
• Low O2 - Anaerobic Glycolysis
– intense exercise - Lactic Acid
– Acid buildup can inhibit activity
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Carbohydrate
• High O2 - Aerobic Glycolysis
– moderate to low intensity exercise
– Oxygen demand can be maintained and
can support ATP requirements
• breakdown products move to
mitochondria
– completely broken down into CO2 and
H2O
• requires O2
– yields 36 ATP/glucose
– more efficient but slower than
anaerobic
– Predominates for sustained activity
lasting 2 min to 4 or 5 hours
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Carbohydrate Sources
• Blood Glucose and Glycogen
– Main source is muscle glycogen
• Glycogen depletion
– exercise capacity is cut in half
• Carbohydrate loading
– Prevents severe depletion and “hitting
the wall”
• contribution of blood glucose is very
important after 20-30 min
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–
–
–
carbohydrate intake during exercise
30-60 g per hour
maintain blood glucose
delay fatigue 30 - 60 minutes
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Fats : low intensity fuel
• Slow metabolism, important for
bouts longer than 20 minutes
• massive storage
– Adipose
– Muscle
• caffeine increases availability and
utilization
• “hitting the wall” - can only sustain a
fast walk or slow jog
– * because only fuel source is fats*
– Carbohydrates have run out
• Fig 11-3 - ATP formation
• Fig 11-4 - fuel use
• “ Fat burning Zone?? ”
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VO2 max. = 2.0 liters/min
Exercise Intensity (%VO2 max)
L/min
kcal/L
Fat kcal/L
kcal/min
kcal/30 min
Fat kcal/30 min
50%
1.0
4.86
2.43
4.86
146
73
70%
1.4
4.90
1.96
6.86
206
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Conclusion: more fat (and total calories)
is/are burned at a higher intensity for
exercise over the same duration(time).
Power Foods
Dietary Guidelines
• Proper diet will maximize an
athletes potential
• Athletes need to add the energy
required for training to the basal
requirements
– Estimate 5-8 kcal/min (for
moderate activity)
• Assessment of body
composition is important
– body fat %, weight change
– Fluid and electrolyte replacement
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High Carbohydrates
• Higher intake for athletes
• To replenish glycogen stores
• increase carb intake from
5g/day/Kg to 7g/day/Kg
• focus on carbohydrate rich
sources, to supplement needs
• 60 - 70 % of kcal from
carbohydrates
• Fig. 11-4
– potatoes, brown rice, whole grain
pasta
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Carbohydrate loading
• Appropriate for continuous events
lasting over 90 min
– Marathon, triathlon, basketball
tournament, X-country skiing
• shorter events repeated within 24
hours - time trials, heats/finals
• Table 11.2 - daily menu
• couple with tapering of training
(reduction) before competition
• caution, can increase water retention
with glycogen storage
• *Eat Carbo rich foods after exercise
Juice, yogurt…*
• Recommendations for carbohydrate
loading prior to competion - p 389
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Protein
• Small contribution to energy
• endurance 10-15 %, especially with
inadequate Carbohydrates
• ? Anabolic effect of carbohydrate
rich diet?
– Insulin, growth hormone
• protein generally met by balanced
diet
• may need increase for high level
endurance and weight training
athletes
– increase to 1.0-1.6 g/Kg body weight
• From .8g/kg for general population
– AA or protein supplements are not
necessary
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Vitamins and Minerals
• Same or slightly higher
requirements than sedentary
• May be some antioxidant
protection with higher vitamin
C and E
• balanced diet should be fine
• Iron - deficiency anemia
impairs performance
• Calcium
– osteoporosis, stress fracture risk
due to decreased bone density in
female athletes no longer
menstrating regularly
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Body Fluids
• 6-8 cups per day
• Sweat losses, 3-8 cups per hour
• body temperature increases with
loss of 3% body weight in H2O
– reduced endurance, strength and
performance
• Heat Illness
– profuse sweating, headache,
dizziness, nausea, vomiting
– maintain fluid intake, avoid
intense exercise in extremely hot
and humid environments
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Fluid intake
• Drink regularly up to 2 hours before
activity ( water, diluted fruit juice,
sports drink)
• 20 - 30 min before 1-1.5 cups
• during .5 to 1 cup every 20 min
• 6-8 % glucose (sports drinks)
– otherwise impairs absorption
• After, 2 cups per pound lost
– One Litre per Kg
• Sports drinks?
– Carbohydrate and electrolyte
replacement in addition to water may be
important for events lasting longer than
60 minutes in hot weather
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Pre Game Meal
• Light - 300-100 kcal
– 2-4 hours before event
• primarily carbohydrates (70%)
– milk, grapefruit, baked beans,
apples
– sustained release of glucose
• low insoluble fiber
• blend food for easy digestion if
only 1-2 hours before event
– cliff bar, power bar
• ?avoid carbohydrates one hour
before event - athlete specific
• Table 11.5 pre event meals
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After Exercise
• Table 11.7 post event meals
• Carbohydrate rich foods within
2 hours - 50-200g
– fruit juice, candy, sports drinks
• electrolyte replacement
– Na+, K+ - (salt, banana)
• sports drinks most important
for 60 - 90 minute events
– large loss of sweat (and
electolytes)
• glucose polymer (linked
glucose) - OK
– fructose absorbed slowly
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Learning Objectives
• Design a basic fitness program
• Describe when and how glycogen, blood
glucose, fat and protein are used to meet
energy needs during different types of
activity
• Differentiate between anaerobic and
aerobic use of glucose - including
advantages and disadvantages
• Show how muscles adapt to an increase in
physical activity
• Outline how to estimate an athletes energy
needs and the nutrient requirements of a
training diet (carbs)
• Examine problems with rapid weight loss
and dehydration
• Describe effects of various ergogenic aids
on an athletes performance
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