+ Sports Nutrition FSHN 185 Spring 2013 Joy Galloway Graduate Student of Nutrition Science.
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Transcript of + Sports Nutrition FSHN 185 Spring 2013 Joy Galloway Graduate Student of Nutrition Science.
+
Sports NutritionFSHN 185 Spring 2013Joy GallowayGraduate Student of Nutrition Science
+
http://www.youtube.com/watch?v=IucEW2zSzCQ
+Overview of Sports Nutrition
What makes a person fit?
How do anaerobic and aerobic metabolism differ?
What are special nutritional needs of athletes?
What are ergogenic aids?
What are physical activity recommendations?
+What Makes a Person “FIT”?
Fitness = a set of attributes related to the ability to perform routine physical activities without undue fatigue
2012 USA Men’s Swim Team
+Some Health Benefits of FitnessPhysical: Reduced Risk of Chronic
Disease & Mortality (CVD, T2 Diabetes, Some Cancers & Joint Disorders)
Psychological: Improves Mood, Self-Esteem, & Overall Well-Being
+
Components of Fitnesso Body Compositiono Flexibilityo Cardiorespiratory Enduranceo Muscle Strength & Endurance
+Components of Fitness:Body Composition
+Components of Fitness:Flexibility
Range of motion—How far can you bend and stretch your muscles & ligaments?
+Components of Fitness:Cardiorespiratory Endurance
Ability to use oxygen
Measured by aerobic capacity (“VO2 Max”)
Enhanced by aerobic exercise
Decreases resting heart rate / improves cardiovascular efficiency
+Cardiorespiratory EnduranceAerobic Capacity
VO2 Max = mL/kg/min Oxygen the body can use to make ATP
Is also related to #RBC’s in body & iron status
+Aerobic CapacityVO2 Max Values
+Components of Fitness:Muscular Strength & Endurance
Muscular strength: force exerted
Muscular endurance: ability to maintain activities requiring strength
Hypertrophy = growth
Atrophy = loss
…Events requiring Muscular Strength?
…Events requiring Muscular Endurance?
+Aerobic vs Anaerobic MetabolismHow Do They Differ?What Does This Mean Nutritionally??
Aerobic Anaerobic
+Anaerobic vs Aerobic MetabolismAmount of ATP
+Exercise Duration & Fuel Use
+Aerobic Metabolism
Occurs in mitochondria of cell Mitochondria increase in number and size with
training!
Requires oxygen
Can utilize fatty acids, amino acids, and glucose for fuel
With Oxygen!
+Anaerobic Metabolism
Occurs in cytosol of cell
Relies solely on glucose for glycolysis
Intermediates in glycolysis provide electrons for electron transport chain in mitochondria (more ATP!)
Events of short duration! <2-3min
…But anaerobic and aerobic metabolism often occur simultaneously!
Without oxygen!
+PRACTICE Anaerobic & Aerobic
Julie Galloway, English Channel swimmer. 9hrs 51min
+PRACTICE Anaerobic & Aerobic
Ray Lewis, linebacker for Baltimore Ravens
+PRACTICE Anaerobic & Aerobic
Ryan Lochte, WR 200 medley, 1min 49sec
+PRACTICE Anaerobic & Aerobic
Laird Hamilton, professional surfer
+Factors Influencing the Fuel Mix
During Exercise
1) Intensity of Exercise ↑intensity → ↑CHO use
2) Duration of Activity ↑duration → ↑Fat use
3) State of Training ↑endurance training → ↑Fat
use
Sources of energy for muscle at 3 different intensities of exercise*after about 30 minutes of exercise
+When Fuel Runs Out!http://www.youtube.com/watch?v=LKhkvSRQZYo
+Athletes’ NeedsEnergy
+Athletes’ NeedsEnergy
Female athlete triad: Disordered Eating Amenorrhea Osteoporosis
More common in: Weight-bearing sports (e.g. cross-country) Aesthetic sports (e.g. gymnastics, diving)
+Athletes’ NeedsMacronutrients
Protein 10 to 15% of kcal
Fat 20 to 30%
CHO 55 to 70%
Longer duration training → ↑CHO need
Protein 0.8 to 2.0 g/kg body weight Percentage values assume athletes are meeting energy
needs.
Percentages can be very different for athletes attempting weight loss.
+
Recommended Protein Intakes
GroupProtein Intake
(g/kg body weight)
Most adults 0.8
Endurance athletes 1.2 to 1.4
Vegetarian endurance athletes 1.3 to 1.5
Strength athletes 1.6 to 1.7
Vegetarian strength athletes 1.7 to 1.8
Dietary Reference Intakes, 2002ACSM/ADA/Dietitians of Canada Position Statement: Nutrition & Athletic Performance, 2001
Protein NeedsExtent of Training & Sources
+Carbohydrate NeedsType & Intensity of Training
6-10g CHO/kg body weight = recommendation (text p.369)
+Athletes’ NeedsMicronutrients
Sodium & hyponatremia Maintains fluid balance in cells Allows for neural firing Problem with water-only fluid replacement in long events
Iron & anemia Exercise increases use of iron
Increased iron-requiring protein synthesis Increased loss through feces, urine, and sweat
Exercise increases need for iron Females and vegetarians at greater risk
+Iron’s Role in Exercisehttp://www.youtube.com/watch?v=eor6EK_JP40&feature=fvwrel
+Questions so far?
+Athletes’ NeedsWater
Water is crucial for: Blood volume
maintaining low heart rate delivering nutrients and oxygen removing wastes
Maintaining low body temperature carrying heat to periphery producing sweat …1.5L/hour!
Why does the body lose so much water during exercise?
1. Working muscles → heat
2. Blood flow carries heat to the skin
3. Evaporation of water from the body surface is the most efficient way to remove heat
**water both transports and removes heat**
Sweat loss ~ 1.5 Liter (~6cups) / Hour
+
Water loss as little as 2% of body weight can impair physical and mental performance. 2% weight loss for 150 lb person = 3 lbs 1.5 liters = ~ 1.5 quarts = 3 lbs
Dehydration Impairs Athletic Performance
+Dehydration & Heat-Related IllnessHeat Cramps
Involuntary muscle spasms caused by heat & electrolyte loss.
Heat Exhaustion Rapid heart rate, low blood pressure, disorientation,
loss of consciousness.
Heat Stroke Can be fatal. Body temp over 105F. Inability to
produce sweat. Extreme confusion, loss of consciousness, death.
+Athletes’ NeedsWater
Before exercise, drink enough to be fully hydrated. ~2 cups usually.
During exercise, drink enough to prevent weight loss. 6-12oz every 15-20min. If you’re thirsty, you’re already dehydrated!
After exercise, rehydrate! 16-24oz per pound lost, or 16oz immediately+.
Cooler water is absorbed faster.
Water with 6-8%CHO is absorbed faster.
+
Optimizing Performance Nutrition is ImportantBefore, During, & After
Competition
+Optimizing PerformanceBefore
Begin properly hydrated.
Maximize glycogen stores.
+
Carbo-Loading
Controversial on best method
~3 days before race, consume 10-12g CHO/kg (140lb ~2800kcal CHO)
Can DOUBLE glycogen stores
Holds 3g water per g glycogen
Can really only be helpful for events >90min
http://www.youtube.com/watch?v=9-e5y-3dyUs
+Optimizing PerformanceBefore
Begin properly hydrated.
Maximize glycogen stores. Carbo Loading (10-12g Cho/kg) to boost glycogen stores. Important for competitions over 90min. Extra benefit of storing 3g water per g glycogen.
Pre-exercise meal ~300kcal high in Cho.Low fat & fiber to minimize GI distress &
bloating.Caution with fructose & diarrhea.
Your gut is trainable!!
+Optimizing PerformanceDuring
Prevent excess fluid loss
CHO during exercise if lasts >1hr can help maintain glycogen stores Glucose & fructose combination In sports drink or a gel or snack 30-60g/hr recommended
Sodium during exercise >1hr, especially >3hrs In most sports drinks Improves water and CHO absorption Stimulates thirst
+Optimizing PerformanceAfter
Replenish fluid (ASAP), electrolytes, and glycogen lost
Provide protein to build and repair muscle tissue
High CHO snack within 30min (glycogen window!) Enhanced repair with some protein 1.0-1.5g/kg CHO for training Regular 55% CHO diet for regular exercisers
+
Ergogenic AidsSubstances, appliances, or procedures that improve athletic performance
+
Ergogenic AidsVitamins & Minerals
Not really an Ergogenic Aid, because typically do not enhance performance at all unless there was a deficiency.
Can cause harmful toxicity!
+Ergogenic AidsBuilding Muscle
Protein = Usually adequate in diet of adequate Calories.
Growth hormone = Banned by WADA. Improves anaerobic exercise capacity but can cause disfigurement and fatal heart dysfunction.
Amino acids = Unhelpful with strength training when adequate complete proteins consumed.
Anabolic steroids = Banned by NCAA and IOC. Hormones that mimic effects of testosterone by increasing muscle size and strength, but cause atrophy of testes, water retention, coronary disease, liver disease, and severe mood swings.
+Ergogenic AidsEnhancing Short, Intense ActivitiesSupplements for improving quick bursts of intense activity:
Beta-hydroxy-beta-methylbutyrate (“HMB”) = dubious!
Bicarbonate (baking soda) = some results show delayed fatigue due to its pH stabilization BUT causes cramps & diarrhea …Needs more research!
Creatine = found naturally in muscle (PCr system) Used for <30sec activity BUT body adapts to creatine production <5g/day appears safe but FDA recommends consulting physician
first
+Ergogenic AidsEnhancing Endurance
Carnitine = needed to transport FA to mitochondria But the body makes all we need!
MCT = quickly absorbed FA’s But haven’t shown to help performance!
Caffeine = enhances release of FA’s Preserves glycogen stores & delays fatigue Improves alertness & concentration But can cause GI distress Can improve endurance if take 3-6mg/kg within 1hr (2.5cups of
coffee)
EPO = stimulates bone marrow to produce RBCs Banned substances, commonly abused by cyclists Can cause heart attacks & stroke
+Physical Activity Recommendations32% of Americans get NO physical activity in their leisure time!
+Physical Activity Recommendations
150min of moderate-intensity or 75min of vigorous-intensity aerobic zone exercise/wkAerobic zone = 60-85% of HR max
& 2 days/wk of muscle-strengthening exercisesNonconsecutive days
Recovery important for muscle-strengthening exercise & for serious athletes to prevent “overtraining syndrome”
+
Curious?
Advanced Sports Nutrition-By Dan Bernot
Nutrition for Health, Fitness & Sport-By Melvin H. Williams
Australian Institute of Sporthttp://www.ausport.gov.au/ais/nutrition