Chapter 14 Sports Nutrition

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Chapter 14 Sports Nutrition Powered By Docstoc
					Chapter 10

 Nutrition:
 Fitness &
  Sports
         New Diet Analysis 2~
   See website for assignment/details

              http://people.ucsc.edu/~taj/Chem80A
               OUTLINE

Physical activity & Beginning an Exercise Program

Fuel Types for Exercise

Fuel Requirements for Exercise
             Physical Fitness

   “The ability to perform moderate to
    vigorous activity without undue
    fatigue”

 Fat   usage by the body
    – Increased physical fitness means
      improved usage of fat for energy
Benefits of Physical Activity
    Nutrition and Physical Activity
   Only 15% of adults are regularly physically
    active (U.S.)

NUTRITION (intake)


                       Physical Performance


Nutrient Use
Beginning an Exercise Program
   Start out slowly
   Vary your workout—Make it fun
   Include others—Keep accountable (notebook/log)
   Set attainable goals (min. 6 weeks)
   Set aside specific time (daily or weekly)
   Reward yourself
   Focus on long-term and not on occasional
    setbacks
       2005 Dietary Guidelines for
               Americans
   30 minutes/day physical activity 3X /week
    – Reduce risk of chronic disease
   60 minutes/day physical activity, 3X /week
    – Manage body weight and prevent weight gain
   90 minutes/day physical activity, 3X /week
    – Sustain considerable weight loss
               Challenge Question
   What is your target heart rate zone?
    Target heart rate zone is the Heart beats/ min (based on age)
    that you are trying to maintain during spec. exercise


   How do you calculate it?
      220-(age) = ? (0.6 –low end) – (0.9 –high end)

   Why does it matter?
If you are interested in burning more fat
(need the aerobic “oxygen zone” –low end, ~120 beats/min)
Light jog or brisk walking, weight lifting, swimming
If you want to improve cardiovascular (Heart health)
focus on anAerobic (high output end 180 beats/min) e.g. running,
               OUTLINE

Physical activity & Beginning an Exer. Program

Fuel Types for types of Exercise

Fuel Requirements for Exercise
         Fuel for Muscle Work

 ATP
 Chemical energy
    – Used by cells for muscle contractions
   Only small amount is stored in resting cells
    – 2-4 seconds worth of work
   Other sources of energy are needed
        Phosphocreatine (PCr)

   High-energy compound
    – Formed and stored in muscle cells
           PCr + ADP           Cr + ATP




   Activated instantly
    – Replenishes ATP

   Sustains ATP (work) for a few minutes
             Anaerobic Glycolysis
 Limited oxygen—Intense physical activity
  (running)
 Pyruvate is converted to lactate
 Produces 2 ATP per glucose
    – ~5% of energy potential
   Replenishes ATP quickly
   Cannot sustain ATP production
    – 30 seconds to 2 minutes of work
   Lactate build-up (soreness)
    – Changes acidity that inhibits glycolysis enzymes
            Aerobic Glycolysis
 Plenty of oxygen available (talk test)
 Low to moderate intensity (jogging)
 Produces 36-38 ATP per glucose
    – 95% of energy potential
 ATP replenished slowly
 Sustained ATP production
    – 2 minutes to 3 hours of work
    – Best for burning fat
       Glucose Utilization




Glycolysis
Sugar burning
No Oxygen
“No talking”    Citric Acid Cycle
Running         Fat Burning
                <jogging
                     Glycogen
 Temporary storage of glucose in liver and
  muscle
 Muscle glycogen
    – Used only by that muscle
 Liver glycogen released into bloodstream
 During low to moderate intensity
    – Can sustain work for up to 2 hours
   “Bonking” running/ jogging along –
    – “hit the wall”
    – Depleted glycogen
    – Work at ~50% of maximal capacity
                 ATP Formation




                                             Glycolysis
                              2 ATPs         Sugar burning
                                             No Oxygen
                                             “No talking”
                                             Running


                                       28-32 ATP
                                       Citric Acid Cycle/ETC
                                       Fat Burning
                                       <jogging
NEED ~ min. 20 Minutes
Before Fat burning ensues
Recommend 40-60 min 3X week
sustained exercise
       Maintaining Normal Blood
            Glucose Level
   Important
    – For activity lasting longer than 20-30 minutes


   Intake of 30-60 gm carbohydrates per hour
    – During strenuous endurance activity
    – Delays fatigue by 30-60 minutes

           34 grams
Fat Fuel (Fatty Acid)
 Majority of stored energy in the body
 Fatty acids
    – Converted to ATP by muscle cells
   12 ATP produced
    – Per each turn of the Citric Acid Cycle
    – 108 ATP for each 16 C fatty acid chain!!!!!!!!!
   Trained muscles
    – Have more mitochondria
    – Have greater ability to use fat as fuel
    – The more trained muscles respiring, the more fat burned
    – Advocate full body workout(s): dancing, swimming, biking,
      jogging, yoga, weightlifting, brisk walking, sports
                Fat Fuel
 Rate   of fat use
  – Dependent on concentration of fatty acids
    in the bloodstream
 Prolonged   exercise >>20 min
  – Fat becomes main fuel source
 Intense   activity (e.g. sprinting)
  – Fat is not a major source of fuel
  – Requires more oxygen for aerobic
    breakdown (than glucose)
    Protein—Minor Source of Fuel
   During rest and low/moderate exercise
    – Provides 2%-5% of energy needs
   During endurance exercise
    – Provides 10%-15% of energy needs
 Branched-chain amino acids provide most
  of the energy (Leu, Isoleu, Val)
 Average diet
    – Provides ample amount of these amino acids
    – Supplements not needed (usually)
Fuel Use During Physical Activity
                   OUTLINE

Physical activity & Beginning an Exer. Program

Fuel Types for types of Exercise

Fuel Requirements for Exercise
               Calorie Needs
 Individual needs vary
 Monitoring weight and body fat
    – If weight falls, increase intake
    – If body fat increases, cut back in fat
      (& kcal) and maintain activity
 Desirable body fat for male athletes:
  5%- 18%
 Desirable body fat for female athletes:
  17%-28%
         Carbohydrate Needs

 Main fuel for many types of activity
 Consume ~60% of total kcal from
  carbohydrate
> 5 gm of carbohydrate/kg body weight
 Aerobic and endurance athletes
    – 7-10 gm carbohydrates/kg body weight
    – ~ 500-600 gm of carbohydrates/day
      Carbohydrate Loading
 Events  lasting longer than 60-90
  minutes
 Maximize glycogen stores
 Tapering of exercise while
  increasing carbohydrate intake
 Additional water weight
   Carbohydrate (CHO) Loading

Days
Before     6     5     4     3     2      1
Com-
petition
Exercise
Time
           60    40    40    20    20    rest

CHO
(grams)
           450   450   450   600   600   600
              Fat Needs
 ~35%    of total kcal (runner, otherwise
  much less . .
 Rich in monounsaturated fats
 Limit saturated fats
 Limit trans fat
                    Protein Needs


   Recommend 1.0 - 1.6 gm protein/kg body weight

   Up to 1.7 gm/km body weight for athletes beginning
    strength training

   Needs are easily met by a normal diet ~ sort of
    – Major Protein supplements are not necessary unless
      attempting to build muscle mass (protein shakes)
    – Excessive protein has not been shown to be beneficial
Current Protein Recommendations
 Vitamins and Minerals
 Vitamin   E and C
  – Slightly higher needs
  – Antioxidant properties           Vitamin C

         riboflavin, vitamin B-6, potassium,
 Thiamin,
 magnesium, iron, zinc, copper, and
 chromium needs
  – May also be higher (role in metabolism or
    sweat)
 Increase   intake of fruits and vegetables
             Iron Needs
 Irondeficiency affects performance
 Sports anemia
  – Increase in plasma volume but not RBCs
 Women    at risk because of
  menstruation
 Focus on iron-rich foods
 Use of iron supplement may cause
  toxic effects
            Calcium Needs
 Restrictionof dairy products by
  women – not good (yogurt, cheeses)
 Irregular menstruation/Amenorrhea
  – Severe bone loss and osteoporosis
  – Extra calcium does not compensate for
    effects of menstrual irregularities
  – Compromises bone health
 Calcium deficiency increases risk of
 stress fractures
         Challenge Question
   What can the female athlete do to her diet
    and physical activity level to reestab.
    Monthly mensus?

       Increase Energy (caloric intake)
       Decrease physical activity level
                   Fluid Needs
   Needs of average adults
    – 9 cups per day for women
    – 13 cups per day for men
 Athletes need more (depending on sweating
 Maintenance of body’s cooling system
    – Water helps dissipate heat from working muscles
 Avoid losing more than 2% of body weight
  during exercise
 For every 1lb. lost replace 2.5-3 cups of fluid
Confirming your knowledge -Break

   What are the recommended levels of
    protein in g/kg/body wt. for athletes?
      1.0-1.5 grams/kg of body weight


   What are the recommended additional
    vitamin antioxidants required for athletes?
                  Vitamin C and E



                  STOP Here - Have a Nice Weekend 
                    Remember your Diet Analysis II
                          Due Thursday . . .
                    OUTLINE
Midterm results

CHAPTER 10 – Nutrition & Fitness
                  Heat Exhaustion
                  Sports drinks & Bars
                  Pre- endurance & Recovery from Training
                  Ergogenic Aids & Training Supplements

CHAPTER 11 – Eating Disorders
     Brief - Highlights

       BREAK – Dietary EFAs & Cereal Party



CHAPTER 13 – Food Safety
    Midterm Results – 395 pts
 High 375 (94%)
 Low 192 (50%)
 Avg 305 (77%)

Standard Grade     Curve
A > 355            A > 320 (15)
B > 315            B > 280 (13)
C > 275            C > 210 (8)
D < 235            D < 200 (1)
                    OUTLINE
Midterm results

CHAPTER 10 – Nutrition & Fitness
                  Heat Exhaustion
                  Sports drinks & Bars
                  Pre- endurance & Recovery from Training
                  Ergogenic Aids & Training Supplements


CHAPTER 11 – Eating Disorders
     Brief - Highlights

       BREAK – Dietary EFAs & Cereal Party

CHAPTER 13 – Food Safety
                Heat Exhaustion
   Heat stress causes depletion of blood volume due
    to fluid loss
   Body heat is dissipated through evaporation of
    sweat (fluid)
   Fluid loss (sweat): ~3-8 Cups per hour
   Humidity interferes with sweat production
   Dehydration decreases endurance, strength,
    performance
   Signs: Profuse sweating, headache, dizziness,
    nausea, weakness, visual disturbances
               Heat Cramps
   Frequent complication of heat
    exhaustion
    – Exercising in heat
    – Significant sweating
    – Consuming water without sodium
   Painful muscle contractions
    – 1-3 minutes at a time
 Ensure adequate salt and fluid intake
 Exercise moderately at first in the heat
                Heat Stroke
   High blood flow to working muscles
    – Overloads body’s cooling system
    – Sweating ceases
    – Internal body temperature reaches 104° F
    – Fatality rate high
   Symptoms:
    – Nausea, confusion, irritability, poor
      coordination, seizures, coma
 Replace fluids
 Monitor weight change (fluid loss)
 Avoid exercising in hot humid conditions
                    OUTLINE
Midterm results

CHAPTER 10 – Nutrition & Fitness
                  Heat Exhaustion
                  Sports drinks & Bars
                  Pre- endurance & Recovery from Training
                  Ergogenic Aids & Training Supplements


CHAPTER 11 – Eating Disorders
     Brief - Highlights

       BREAK – Dietary EFAs & Cereal Party

CHAPTER 13 – Food Safety
  Sports Drinks For
 Endurance Exercise
 Recommended      for activity > 60 minutes
  – Help maintain blood glucose level and blood
    volume
  – Delay “Hitting the Wall” glyocgen depletion
 Supply   electrolytes: Na, K, P, Cl

 <60   minutes: Water adequate:
  – Nutrients are easily replaced by diet
             Gels and Bars


 Provide additional fuel
 Should be taken with fluids
 Expensive source of nutrients
 Ideal bars for endurance athletes
  – Contain 40 gm carbohydrate, 10 gm of
    protein, 4 gram fat, 5 gm of fiber
  – Fortified with vitamins and minerals
Content of Energy Bars and Gels
        Confirming your knowledge
   After what duration of exercise are Sports
    drinks considered necessary for replenishment
    of glucose and electrolyte stores?

            60 minutes
                    OUTLINE
Midterm results

CHAPTER 10 – Nutrition & Fitness
                  Heat Exhaustion
                  Sports drinks & Bars
                  Pre- endurance & Recovery from Training
                  Ergogenic Aids & Training Supplements


CHAPTER 11 – Eating Disorders
     Brief - Highlights

       BREAK – Dietary EFAs & Cereal Party

CHAPTER 13 – Food Safety
    Pre-Endurance (running) Event Meal

 Light meal 2-4 hours prior to event
 Consisting primarily of carbohydrate (top
  off glycogen stores)
 Low fat (<25% of energy intake)
 Little fiber (prevent bloating, gas)
 Moderate protein
 Avoid fatty, fried foods
 Blended or liquid meal recommended for
  meals eaten 1-2 hours prior
Recovery Meal

 Carbohydrate-richmeal within 2
 hours after endurance event
  – Glycogen synthesis is the greatest
  – 1-2 gm Carbs/kg body weight
 Choose  high glycemic index foods
 Aim for 3:1 carbohydrate-to-protein
 Fluid and electrolyte replacement
    Replenishing Muscle Glycogen
 Availability of adequate carbohydrate
 Ingestion of carbohydrate soon after
  exercise
 Selection of high-glycemic-load
  carbohydrate
 Combination of carbohydrate and protein
  foods
     Nutrition: Fitness/Sports Summary
   Aerobic zone for Fat burning, 120-130 BPM
    – Brisk walking, jogging, dancing, warrior yoga,
    – Stationary bike, treadmill, elliptical, (talk test)
 ~60% carbohydrate diet if athlete
 Eat simple sugar before workout (fruit, drink etc.)
    – Maximizes fat metabolism

 More PROTEIN: Athletes req. 1.0-1.7 g/kg/bdy wt. /day
 Vit C and E beneficial (oxidative stress)
 Weightlifting: focus on the eccentrics. . . Best stimuli
                    OUTLINE
Midterm results

CHAPTER 10 – Nutrition & Fitness
                  Heat Exhaustion
                  Sports drinks & Bars
                  Pre- endurance & Recovery from Training
                  Ergogenic Aids & Training Supplements


CHAPTER 11 – Eating Disorders
     Brief - Highlights

       BREAK – Dietary EFAs & Cereal Party

CHAPTER 13 – Food Safety
               Challenge Question>
              What is an ergogenic aid?

A mechanical, nutritional, psychological, pharmacological or physiological substance or
              treatment intended to improve exercise performance.



      And what are some examples?

                             See next slide for examples
Ergogenic Aids
Ergogenic Aids
                  Steroid Hormones
     Among the synthetic anabolic steroids are:
              H3 C CH3                     H3 C   OH                 H3 C O
                     OH
                              H3 C
       H3 C                          CH3                     H3 C


  O                       O                              O
      Methandie none           Methe nolone            4-An dros tene-3,17-dione



Why are these hormones of interest?

Do steroids really work? i.e. improve
           muscle mass
              and performance? . . .
                                       H3 C OH
A resounding Yes . . .                                         H3 C

                             H3 C                     H3 C



                         O                       HO
                             Testosteron e            And rosterone
  Hydroxycut recall

  MAY 2009
  The FDA has received 23 reports of serious liver injuries,
  including a death, linked to Hydroxycut products.

  SUSPECTED CULPRIT  hydroxycitric acid (HCA)

  1 medical study shows associated liver toxicity




Laboratory and animal studies of HCA
have produced results that indicate a potential                hydroxycitric acid
for modulation of lipid metabolism

    Shara et al., 2003, Mol. Cell. Biochem. 254 (1-2): 339–46
     Nutrition: Fitness/Sports Controversies
   Any Additional Ergogenic aids????
   Best natural/safe muscle building: Creatine
    – Add to estab. resistance training routine, not an anabolic!

   Hydroxycut recall
   Acai?
   5 hour energy drinks?
   Rely on your own case study?
    –   Little scientific data to back up claims. . .
    –   Try out a scientific lit. search??? Folklore/Fad  Added Fitness???
    –   Use at own risk, < upper limit
    –   Maybe toxic, maybe ok?
    –   Try for min. 6 weeks?, evaluate
END CHAPTER 10
Chem 80A Class Interests



  Increase Energy (caloric intake)
  Decrease physical activity level

				
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