Introduction - PowerPoint PPT Presentation

• Memphis marathon

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NUTRITION FOR ATHLETES & ACTIVE INDIVIDUALS

• Energy is stored as ATP
• ATP supply is limited
• Constant ‘recycling’ of ATP

Exercise

Walking

Running

Cycling

Swimming

ANAEROBIC

Strength training

Sprinting

Throwing

Jumping

Creatine

Carbohydrate

Carbohydrate

Fat

Protein

PHOSPHOCREATINE

• Phosphate – mineral
• Creatine – amino acids
• Stored inside muscle
• 5-6 times more than ATP
• Strength
• 30 seconds

Anaerobic and Aerobic

Preferred fuel of the brain

Limited supply

2,000 calories

20 miles of running

2 hours of running

Lactic acid

Power

60 seconds

2 ATP

Less lactic acid

Greater than 2 minutes

Depletion after 90 to 120 minutes

Chronic depletion

36-38 ATP

5.0 calories per liter of oxygen

Fatigue

Hitting the wall

Bonking

98 . . . . . . . . . . Potato, Russet, Baked

97 . . . . . . . . . . Parsnips

87 . . . . . . . . . . Honey

89 . . . . . . . . . . Sport drinks

72 . . . . . . . . . . Bagel

70 . . . . . . . . . . Potato, White

MEDIUM INDEX (56-69)

69 . . . . . . . . . . White Bread

66 . . . . . . . . . . Brown Rice

64 . . . . . . . . . . Raisins

64 . . . . . . . . . . Beets

62 . . . . . . . . . . Bananas

60 . . . . . . . . .Soft Drinks

LOW INDEX (< 55)

34 . . . . . . . . . . Pears

29 . . . . . . . . . . Kidney Beans

26 . . . . . . . . . . Peaches

26 . . . . . . . . . . Grapefruit

25 . . . . . . . . . . Plums

23 . . . . . . . . . . Cherries

15 . . . . . . . . . . Soybeans

• Relative large store
• 70,000 kcal (12% body fat)
• More energy per gram
• Fat = 9 kcals/gram
• Carbs = 4 kcals/gram
• Glycogen sparing effect

• Slower fuel
• 2 to 6 times slow than glycogen oxidation
• Requires more oxygen

Gluconeogenesis

Glucose production

Muscle repair

• Carbohydrates for energy
• Protein for muscle repair and growth

Competingwithandwithoutadequate carbohydrates

• Protein is not a major source of energy
• Active people need more protein than the RDA
• However…
• Most people already consume more than the RDA
• Excess protein is stored as fat
• High protein in the diet can cause dehydration and stress to the kidneys

• RDA (average sedentary)
• = 0.4 grams per pound (8% total calories)
• = 0.8 grams/kilogram
• Resistance training
• = up to 0.8 g per pound (15% total calories)
• = 1.8 g per kg per day
• Endurance training
• = up to 0.6 g per pound (10% total calories)
• = 1.4 g per kg per day

No Growth

No Growth

Muscle Hypertrophy

Muscle Hypertrophy

Muscle Atrophy

Muscle Atrophy

Peaks are ~ 2 hours apart.

• Protein should be consumed post-exercise to aid in muscle recovery and repair.
• A small dose (0.1 g/kg) every 1-2 hours for 6 hours will promote a positive balance or anabolic state
• Example: 170 lbs = 7.7 grams (~1 cup of milk)
• Tuna, peanut butter, etc.
• Adequate carbohydrate intake is needed to provided the energy for muscle repair and growth (4:1 ratio)

• Carbohydrate: The Energy King
• Fruits, Vegetables, and Whole Grains
• Protein: Building and Repair
• Diet
• 1.4 - 1.8 grams per kilogram
• 0.6 – 0.8 grams per pound
• Post-exercise
• 0.1 g/kg every 1-2 hours post-exercise

CARBS

CARBS

FATS

INTENSITY

~ 60%

FATS

~ 2 hours

DURATION

Energy

• Muscles
• Brain and Nerves

Concerns

• Hypoglycemia
• Hitting the wall or “bonking”

Simple(sugars)

Complex

• IS THERE ENOUGH CARBOHYDRATE?
• Total of 600-1500 kcals
• Grains: 6-11 SERVINGS = 450-600 kcals
• Vegies: 3-5 SERVINGS = 70-500 kcals
• Fruit: 2-4 SERVINGS = 80-400 kcals
• Active people may need up to 2000 kcals of carbohydrate or more.

• Sedentary: 55-60% of total calories
• Only 10 percent should be from sugar
• Active: 60-70% of total calories
• 3-5 grams per pound
• ~600 grams (2,400 kcals) for 150 lb person
• Note: 50 to 100 grams (200-400 kcals) per day to spare protein

• CARBOHYDRATE LOADING
• Increase carbohydrate intake to 70%
• Taper workouts
• Not necessary unless the activity will be longer than 90-120 minutes.
• More beneficial in cyclists than runners
• Water gain (3 grams H20 per gram of glycogen).

Moderate carbs, taper (2-3 days)

High carbs, taper or no exercise (2-3 days)

Competition

EXERCISE LESS THAN 1 HOUR

• 1 hour before: 1g per pound of low glycemic CHO
• High glycemic index – greater insulin response
• Low glycemic index to avoid hypoglycemia during exercise

EXERCISE LONGER THAN 1 HOUR

1- 4 hours before: high CHO meal

2 grams of carbohydrate per pound

Limit fat and protein intake

1 hour before: 1g per pound of low glycemic CHO

• Avoid hypoglycemia
• Optional: 50-60 grams of LGI CHO immediately before
• Liquid form e.g. sport drink

• EXERCISE LESS THAN 1 HOUR
• High carbohydrate pre-exercise meals
• High CHO snack (bagel, banana, etc.) about 1 hour before exercise

• DISCONTINUOUS EXERCISE
• High-carbohydrate, pre-exercise meals improve exercise capacity.
• Sports drinks during exercise.
• May need to consume >100 calories per hour
• Sports drinks during prolonged exercise helps delay the deterioration in motor skills.

• EXERCISE LONGER THAN 1 HOUR
• Drink or eat every 15-30 minutes during exercise or breaks
• 30-60 grams per hour
• 120-240 kcals per hour
• High glycemic index CHO
• Liquid
• 8 ounces sport drink

= 56-72 calories)

• Solid
• Energy gels = 100 calories
• Candy
• Fruit

Power output (intensity level) with and without carbohydrates during exercise

EFFECT OF LOW CARBOHYDRATE DIET ON PROTEIN

• Glycogen sparing

• Caffeine
• Chromium
• Carnitine
• Clenbuterol

1. Moderate doses of caffeine ingested 1 h prior to exercise enhance the performance of certain types of endurance exercise in the laboratory.

2. Caffeine ingestion increases plasma free-fatty acid concentrations and muscle triglyceride use and spares muscle glycogen.

3. Caffeine appears to enhance performance during short-term, intense cycling lasting ~5 min in the laboratory and in simulated 1500 m race time.

4. Potential mechanisms for improving performance during intense exercise lasting 5-20 min include direct effects of caffeine on the central nervous system and/or excitation-contraction coupling and increased anaerobic energy provision in skeletal muscle.

• Chromium is an essential trace mineral.
• It has an extremely low gastrointestinal absorption rate, so supplement manufacturers have bound chromium with picolinate (CrPic) to increase the absorption and bioavailability.
• Chromium seems to function as a co-factor that enhances the action of insulin.
• Promoters of CrPic claim it increases glycogen synthesis, improves glucose tolerance and lipid profiles, and increases amino acid incorporation in muscle.

• Early researchers demonstrated anabolic-steroid-like effects with dosages of 200 mg/day.
• More recent studies failed to demonstrate any significant improvement in percent body fat, lean body mass, or strength.
• Most studies of CrPic supplementation reveal no side effects except gastrointestinal intolerance with dosages of 50 to 200 micrograms/day for less than 1 month.
• The use of chromium picolinate supplementation as an ergogenic aid should be strongly discouraged.

• Carnitine: found in meats and dairy products and synthesized from lysine and methionine.
• Theory: Increases free fatty acid transport across mitochondrial membranes, carnitine may increase fatty acid oxidation and utilization for energy.
• Early studies showed an ergogenic effect.

• A more controlled study by Vuchovich et al failed to demonstrate any glycogen-sparing effect or reductions in lactate levels while supplementing with 6 g/day of L-carnitine.
• Finally, many currently available supplements actually contain D-carnitine, which is physiologically inactive in humans but may cause significant muscle weakness through mechanisms that deplete L-carnitine in tissues.
• Carnitine should not be advocated as an ergogenic supplement.

• NEEDS
• Replace glycogen in muscles and liver
• Protein for muscle repair

Competingwithandwithoutadequate carbohydrates during recovery

• CARBOHYDRATES & PROTEIN
• A total of 50-100 grams of CHO and 10-20 grams of protein.
• Repeated with a ~4:1 ratio of CHO & protein every 1-2 hours until next meal

• High carbohydrate intake before exercise
• 120-240 kcals per hour if exercise longer than 60 minutes
• 4:1 ratio of carbohydrate and protein every 1-2 hours after exercise

Water, Sugar, & Electrolytes

• Get hydrated
• Drink extra fluids the day before
• 16-24 ounces, 2 hours before exercise
• 8-16 ounces 5-10 minutes before
• Know your stomach
• Try new fluids/foods during the off-season or with training workouts

• Needs from fluids:
• Water to off-set dehydration
• Energy, if exercise longer than 1 hour
• Electrolytes, if exercising in hot, humid conditions

• WATER
• Sweat rates of 1-2 liters per hour
• Maximal absorption of fluids is less than maximal sweat rates
• Therefore, high sweat rates lead to dehydration (lose 2-5 lbs per hour)
• Fatigue
• Hyperthermia

• ENERGY(sugar)
• Most sport drinks contain some form of sugar (sucrose, glucose, corn syrup, polymers, etc.)
• Recommendation: 6-8% solution of sugar
• No difference in the effectiveness of different sugars

• ELECTROLYTES
• Na, Cl, & K but sweat also contains traces of amino acids, HCO3, CO2, Cu, glucose, hormones, Fe, lactic acid, Mg, N, PO4, urea, vitamins and Zn.
• Sodiumis the only one that may possibly need to be replaced during exercise

• OTHER INGREDIENTS
• Vitamins
• Minerals
• Caffeine
• Herbs
• etc

• WATER v. SPORT DRINKS

• Water. Yes, especially in hot, humid conditions.
• Energy (sugar). If exercise is longer than 60 min.
• Electrolytes. Sodium if hot, humid conditions.

COMMON SPORTS DRINKS

12-20 oz 2 hours before

During Exercise

8-12 oz every 15-20 minutes

Sports Drink?

> 60 minutes

Hot, humid conditions

After Exercise

Replace fluids

16-24 ounces per pound lost.

Sodium

• OTHER RECOMMENDATIONS
• Cool, 59-72° F
• Don’t wait until thirsty.
• Non-carbonated
• Avoid caffeine (?)

Do active people need extra vitamins?

• B complex:
• Thiamin (B1), Riboflavin (B2), Niacin,
• Pyridoxine (B6), Pantothenic acid, Folate,
• B12, and Biotin
• Antioxidants: A, C, E
• Fight free-radicals from aerobic energy production.

Do active people need extra minerals?

• Women
• Calcium
• Iron
• Hot humid conditions
• Sodium

What you don’t get.

• Fiber
• Phytochemicals
• Allium (garlic)
• Capsaicin (hot peppers)
• Isoflavens (soybeans
• Polyphenols (grapes)

Also, varying bioactivity

Here?

Here?

• Low blood sodium a.k.a. “water intoxication”
• Caused by drinking large quantities of water during events longer than 4 hours
• Na lost in sweat and remaining Na becomes diluted due to large water intake
• Can be lethal - cerebral edema.

• GATORADE SPORT SCIENCE EXCHANGE
• "ENERGY" DRINKS: HELP, HARM OR HYPE?”
• Many products marketed as energy drinks contain high concentrations of carbohydrate and some caffeine.
• Some energy drinks contain herbs, amino acids, protein, and other substances, usually in such small amounts that they are unlikely to have any noticeable effect on performance.
• The content of some of these products may result in inefficient absorption of fluid and nutrients from the intestine, with the possibility of gastrointestinal distress.
• Many energy drinks are quite costly and, because of their composition, are not suitable for use by athletes.
• Athletes should be educated about these products and guided towards other foods and fluids that will not pose potential risks.

GATORADE SPORTS SCIENCE EXCHANGE

“CAFFEINE AND EXERCISE PERFORMANCE”

• Caffeine appears to enhance performance during short-term, intense cycling lasting ~5 min in the laboratory and in simulated 1500 m race time.
• However, positive ergogenic effects of caffeine are much less frequent during sprint exercise lasting less than 90 s and in incremental exercise tests lasting 8-20 min.

(continue)

• Moderate doses of caffeine (6 mg/kg body weight) ingested 1 h prior to exercise enhance endurance exercise.
• Increases plasma free-fatty acid concentrations and muscle triglyceride use and spares muscle glycogen.
• Diuretic factor
• Caffeinated diet-cola retains 50-60%
• Water = 60-70%
• Sport drink = 65-75%

• Active people require a diet high in carbohydrate.
• Low carb diets (e.g. Atkins diet) are not designed for active people.
• Most healthy food guides are also high in carbohydrates and very compatible with the needs of active people.
• However, active people should focus on low glycemic index carbs (fruits, vegetables, and whole grains) for meals and snacks between workouts
• When needed, high glycemic index carbs (sugars) should be consumed during exercise and in the few hours after exercise.

• Nutrition Data
• www.nutritiondata.com
• Nutrition Analysis Tools and System
• nat.crgq.com
• Gatorade Sports Science Institute
• www.gssiweb.com

www.physsportsmed.com/personal.htm

AUSTRALIAN SPORTS COMMISSION

http://www.ais.org.au/nutrition/

AMERICAN JOURNAL OF CLINICAL NUTRITION

http://www.ajcn.org/

GATORADE SPORTS SCIENCE INSTITUTE

http://www.gssiweb.com

PENN STATE

http://nirc.cas.psu.edu/fitness.cfm

UNIVERSITY OF ILLINOIS

http://www.urbanext.uiuc.edu/hsnut/

NUTRITION ANALYSIS

http://www.ag.uiuc.edu/~food-lab/nat/

UNIVERSITY OF MONTANA

http://btc.montana.edu/olympics/nutrition/default.htm

FOOD AND NUTRITION INFORMATION CENTER

http://www.nal.usda.gov/fnic/etext/000054.html

SPORTS COACH

http://www.brianmac.demon.co.uk/nutrit.htm

NCAA

http://www.drugfreesport.com/choices/supplements/nut-gen.html

NUITRITION ACTION NEWSLETTER

http://www.cspinet.org/nah/index.htm

BLONZ

http://blonz.com/

• Nancy Clark’s Sports Nutrition Guidebook (Human Kinetics)
• Nutrition for Health, Fitness and Sport. Melvin Williams (WCB McGraw-Hill)

• Nutrition and Athletic Performance.
• Medicine & Science in Sports & Exercise. 32(12):2130-2145, December 2000.
• ACSM Position Stand: Exercise and Fluid Replacement.
• Medicine & Science in Sports & Exercise. 28(10):i-ix, October 1996.
• Role of Dietary Supplements for Physically Active People
• American Journal of Clinical Nutrition Vol. 72, No. 2., Aug 2000.