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Jared and the Wall


									Jared and the Wall

Eduard Skachkov
Liz Witowski
Caitlin Blau
Lindsay Wolslegel
                 Meet Jared…
   About to run a marathon (26.2 miles)
   Has had sufficient amount of training to be
    physically fit for the race
   Wants to do everything physically possible to
    prevent himself from “hitting the wall”
   Has heard that plenty of carbs before the race
    will prevent muscle fatigue and central fatigue
           Agenda: we will discuss…

   What it means, physiologically, for a runner to
    “hit the wall”
   How carbohydrates help prevent muscle fatigue
    and central fatigue
   Nutritionally, what a runner like Jared needs to
    do to prevent these physiological symptoms
   Our analogy, how glycogen stores are like a
    debit card
               “Hitting the Wall”
   Aka “bonk” – in cycling
   Body stores 1500-2000 kcal worth of glycogen
   Glycogen stores depleted after about 2 hours of
    intense exercise
   Alternate source of energy metabolism:
       Breakdown of lipids
   What are the consequences?
             Peripheral Fatigue
   At start of race, you burn 75% carbohydrates,
    25% fatty acids
   Run too fast, and you will metabolize glucose
    anaerobically (inefficient, lactic acid buildup
    causes pain and disrupts enzyme function.)
   Deplete muscle and liver glycogen (mile 20), and
    your body has to rely on fatty acid metabolism
    (slow, requires oxygen and glucose.)
                Central Fatigue
   CNS gets “first crack” at glucose; muscles
    fatigue first
   As blood glucose decreases, CNS function is
    impaired (confusion, willpower and mood
    changes, hallucination)
   Serotonin levels in brain rise, peak at exhaustion,
    and dopamine effect is lessened
   “Central governor theory” – CNS fatigue
    prevents total muscle exhaustion
                      Pre-Race Breakfast

   High carbohydrate meal/snack that is WELL-TOLERATED on
    the stomach should be eaten 1 to 4 hours prior to race(2-3 hours
    may best to allow for stomach emptying)
    Decrease carbohydrate and calorie content of the meal/snack,
    the closer to exercise the meal/snack is consumed
    Include some lean protein to enhance fullness
    Examples for an average athlete:
    1 hr before: a banana and a cup of bite-sized Mini Wheats or
    small turkey sandwich and 16 oz. sport drink or a commercially
    produced energy bar such as Powerbar.
    3 hrs before: bagel sandwich with turkey and veggies , 1 banana,
    1 cup low fat fruit yogurt and hand full of pretzel twists (1 oz or
    16 twists), 2 cups skim milk and a Rice Krispie treat
                      During the Race

    Jared needs to ingest a mix or water, carbohydrates and
    electrolytes that are easy on his stomach to replace his losses
   Drink 8 oz every 15-20 minutes - 1/2 cup (4 oz) at every mile
    marker/water station
    Carbohydrates to maintain blood glucose concentrations and
    minimize fatigue
    30-60 grams carbohydrate (120-240 calories) need to be
    ingested/replaced every hour. Sports drinks like Gatorade are 4-
    8% carbohydrate so 1 cup should be ingested every 15-20
    minutes i.e.. drink drink 1/2 cup (4oz) at every mile marker
   Jared can meet his caloric needs through Gatorade alone but may
    choose to supplement with bananas, oranges and commercially
    prepared energy gels such as GU.
   Too much food will lead to gastro paresis or stomach bloating
- - - Hitting the Wall = Overdraft Fee - - -
   Davis, Mark J, Nathan L Alderson & Ralph S Welsh. 2000. “Serotonin and central
    nervous system fatigue: nutritional considerations.” American Journal of Clinical
    Nutrition, Vol. 72 No. 2, August 2000, pp. 573-578.
   Latta, Sara. 2003. “Hitting „The Wall.‟”
   Morris, Rick. 2010. “The Marathon Wall – What it is and How to Beat It.”
   Noakes, Timothy D. 2007. “The Central Governor Theory of Exercise Regulation
    Applied to the Marathon.” Sports Medicine, Vol. 37, No. 4-5, 2007, pp. 374-377.
    Accessed through WWU Libraries 26 Apr 2010.
   Clark , Nancy. Nancy Clark's Sports Nutrition Guidebook, 2nd Edition. Sport
    Medicine Brookline, Brookline. MA 1996 pp 72-76.

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