Alimentação desportiva

1. Nutrition and Nutritional
Supplements in Sports

2. Objectives
 Increase awareness that nutrition can affect an athlete’s
performance
 Discuss current nutritional recommendations for athletes
 Review the 1994 Dietary Supplement Health and
Education Act
 Definition of a supplement
 Impact of this legislation
 Discuss specific nutritional supplements commonly used
by athletes
 Do they work?
 Are they safe?
 Review the Anabolic Steroid Control Act of 2004
 Help providers answer questions and address concerns
of athletes, parents and coaches

3. Performance Influencing Factors
Genetics
Training and Conditioning
Nutrition

4. Determinants of the Athlete’s
Energy Requirements
 During intense exercise
 Carbohydrate stored in muscles and liver
(glycogen) is predominant fuel source
 During prolonged exercise
 Fat stores are predominant fuel source
 Fitness level of the athlete
 Well trained endurance athletes burn fat more
efficiently, sparing limited glycogen stores

5. Formula for Estimating the
Body’s Calorie Requirements
 Sedentary person
 Weight (kg) x 25
 Moderately active person
 Weight (kg) x 30
 Active person (endurance athlete)
 Weight (kg) x 40
 Underweight person
 Weight (kg) x 45
 kg = lbs / 2.2

6. Activity for 30 min. 90 lbs. 100 lbs. 110 lbs. 120 lbs. 130 lbs. 140 lbs. 150 lbs. 160 lbs. 170 lbs. 180 lbs. 190 lbs. 200 lbs.
Aerobics step
training, 4" step
(beginner) 131 145 160 174 189 203 218 232 247 261 276 290
Backpacking 180 200 220 240 260 280 300 320 340 360 380 400
Basketball (game) 198 220 242 264 286 308 330 352 374 396 418 440
Bicycling, 10 mph (6
minutes/mile) 112 125 138 150 162 175 188 200 213 225 237 250
Hiking, no load 140 155 171 186 202 217 232 248 263 279 294 310
Jogging, 5 mph (12
minutes/mile) 167 185 203 222 240 259 278 296 315 333 352 370
Raquetball 185 205 225 246 266 287 308 328 349 369 389 410
Running, 08 mph
(7.5 minutes/mile) 274 305 336 366 396 427 458 488 518 549 579 610
Soccer 176 195 215 234 253 273 292 312 332 351 371 390
Swimming (25
yards/minute) 108 120 132 144 156 168 180 192 204 216 228 240
Walking, 3 mph (20
minutes/mile) 72 80 88 96 104 112 120 128 136 144 152 160
Weight training (40
sec. between sets) 230 255 280 306 332 357 382 408 433 459 484 510

7. Carbohydrates
 Non-essential nutrient (human body can make sugar)
 Simple (sugars) and Complex (starches)
 Major fuel source for exercising muscle
 Athletes should ingest 6 to10 gm/kg/day
 60 to 70% of total calories should come from carbohydrates
 Complex carbohydrates (starches) are preferable
 During exercise
 Athletes should consume 25 to 30 gm of carbohydrate for
every 30 minutes of exercise
 Athletes should drink 6 to 8 ounces of water or sports drink for
every 10 to 15 minutes of exercise

8. Carbohydrates
 After exercise
 Athletes should consume 1.0 to 1.5 gm/kg
immediately post exercise and again one
hour later
 To replace muscle glycogen stores
 To prevent gradual depletion of muscle
glycogen stores over time caused by repetitive
daily bouts of heavy exercise
 To decrease muscle breakdown

9. Why Complex Carbohydrates?
 Compared to ingesting simple carbohydrates,
ingesting complex carbohydrates:
 Increases muscle glycogen stores better
 Improves performance and delays fatigue
 Promotes faster stomach emptying
 Causes less stomach upset and indigestion
 Leads to lower blood sugar and insulin levels
 Provides other beneficial nutrients
 Fiber, vitamins and minerals

10. Pre-exercise Meal
 Importance
 Less hunger before and during exercise
 Maintains optimum glycogen stores
 Recommendations
 Emphasize complex carbohydrates (starches)
 1 to 4 gm/kg about 1 to 4 hours prior to event
 Consume less closer to event
 Avoid high fat and high protein foods
 Slower gastric emptying can cause stomach upset
 Avoid high fiber or gas forming foods
 Can lead to crampy abdominal pain

11. Carbohydrate Loading
 Increases the body’s pre-exercise
glycogen stores by 50 to 100%
 Benefits endurance athletes who
compete for longer than 90 minutes
 Can increase endurance up to 20%
 Can increase performance by 2 to 3%

12. Carbohydrate Loading:
One Example of How
Days prior to event Exercise duration Carbohydrate intake
6 90 minutes 5 gm/kg/day
5 40 minutes 5 gm/kg/day
4 40 minutes 5 gm/kg/day
3 20 minutes 10 gm/kg/day
2 20 minutes 10 gm/kg/day
1 rest 10 gm/kg/day

13. Protein
 Athletes require more protein than non-athletes
 12 to 18% of total calories should come from protein
 Protein intake should be tailored to type of training
 1.2 to 1.4 gm/kg/day recommended for endurance athletes
 1.7 to 1.8 gm/kg/day recommended for strength athletes
 Average American diet provides 1.4 gm/kg/day
 Adequate calorie intake is just as important as
adequate protein intake for building muscles
 Too much protein intake can be bad
 Excess protein calories are stored as fat
 Excess protein intake can lead to dehydration and may
contribute to kidney problems

14. Fat
 Major source of energy
 25 to 30% of total calories should come from fat
 Less than 10% of total calories should come from
saturated fats
 Cholesterol intake should be less than 300 mg/day
 Average American diet provides 37% of total
calories from fat

15. Nutritional Supplements
 1994 Dietary Supplement Health and
Education Act
 Definition of a supplement
 Any product that contains vitamins, minerals,
amino acids, herbs, botanicals or a
concentrate, metabolite, constituent, extract or
combination of any of these ingredients
 Removed dietary supplements from FDA
regulation on the front end
 FDA must prove a supplement is dangerous
before its sale can be prohibited

16. Nutritional Supplements
 1994 Dietary Supplement Health and
Education Act
 Manufacturers do not have to provide
scientific proof of claims
 Manufacturers cannot state product is
meant to diagnose, treat, prevent or cure a
disease but can make indirect suggestions
 Created a multi-billion dollar industry that
continues to grow rapidly

17. Vitamins and Minerals
 Essential nutrients
 Human body needs these to produce energy
 No evidence in U.S. studies that taking vitamin and
mineral supplements improves athletic performance
 Being deficient in vitamins or minerals is rare in the U.S.
compared to the rest of the world
 A few studies outside U.S. showed an effect
 Did population studied have some baseline deficiency
treated with these supplements?
 Vegetarian athletes are at risk for being deficient in
vitamins B12, D, riboflavin, iron, zinc and calcium
 Athletes who are strict vegetarians should take a
multivitamin to prevent deficiencies and a calcium
supplement (1000 mg/day) to help prevent bone loss

18. Ephedra or MaHuang
 Herbal forms of the stimulant ephedrine
 80 confirmed deaths related to ephedra use
 Experts suspect many more unconfirmed deaths
 Adverse effects
 High blood pressure (most common)
 Palpitations and increased heart rate
 Seizure
 Thermoregulatory dysfunction
 Stroke
 Heart attack
 Sudden death
 Vasculitis
 Allergic myocarditis (one case reported)
 Acute hepatitis (one case report)

19. Ephedra or MaHuang
 Following the death of two professional
athletes, FDA banned sale of Ephedra
as a nutritional supplement
 Since this time, manufacturers have
started substituting other stimulants
 Citrus Aurantium
 Orange extract
 Chemical structure very similar to ephedrine

20. Anabolic Steroid Precursors
 Dehydroepiandrosterone (DHEA) and
Androstenedione (“Andro”)
 Chemicals that can be converted into testosterone
in human biochemical pathways
 Naturally available in wild yams
 An early study done by a manufacturer of these
products showed no significant increase in blood
levels of testosterone
 Study looked at lower doses of these
supplements than are usually taken and did not
measure ratio of testosterone to
epitestosterone (T:E ratio)

21. Anabolic Steroid Precursors
 Subsequent independent scientific studies
 DHEA
 Does not seem to have much if any effect on fat-free
body mass and strength
 Androstenedione
 Causes a temporary increase in testosterone levels
 Has no effect on body’s ability to make protein
 Does not seem to have any effect on strength
 No long term effect on blood testosterone levels
 Chronic use causes increase in estrogen levels

22. Anabolic Steroid Precursors
Potential adverse effects
May cause liver damage
In females
 Can cause male features in women
 May increase risk of uterus cancer
In males
 Can cause female features in men
 May increase risk of prostate cancer

23. Anabolic Steroids and
Anabolic Steroid Precursors
 Are banned and tested for by the USOC, IOC,
NCAA, NFL, NBA and MLB
 NHL has no official policy and does not
perform testing
 You can be disqualified from participating in
college sports if you test positive for a
substance banned by the NCAA
 Whether or not you knew it was banned
 Whether or not the product was mislabeled

24. Buyer Beware!
 IOC funded study by Shanzer (Germany) from 10/00 to 11/01
 Analyzed 634 products labeled as non-hormonal nutritional
supplements from 13 countries and 215 different suppliers
 94 products (14.8%) were found to be “positive supplements” (contained
anabolic steroid precursors not declared on the label)
 Anabolic androgenic steroid concentrations ranged from 0.01 to 190
micrograms per gram of supplement
 23 products contained steroid precursors of nandrolone and testosterone
 64 products contained steroid precursors of testosterone only
 7 products contained steroid precursors of nandrolone only
 Percentage of positive supplements per country
 25.8% of products bought in Netherlands
 22.7% of products bought in Austria
 18.8% of products bought in UK
 18.8% of products bought in US (45 positive out of 240 tested)

25. Anabolic Steroid Control Act of 2004
 Signed into federal law on October 22, 2004
 Amends the Anabolic Steroid Control Act of 1990
 Modifies the definition of anabolic steroids to include
tetrahydrogestrinone (THG), androstenedione, and specified
related chemicals
 Directs the U.S. Sentencing Commission (USSC) to review federal
sentencing guidelines with respect to anabolic steroid-related
offenses
 Amends guidelines to provide for increased penalties
 Authorizes the Attorney General to exempt from regulation any
compound, mixture, or preparation containing an anabolic steroid
that does not present a significant abuse potential
 Directs the Secretary of Health and Human Services to award
grants for science-based education programs in elementary and
secondary schools to highlight the harmful effects of anabolic
steroids and to ensure that the NSDUH includes questions
concerning the use of these drugs.
 Source: Library of Congress

26. Conclusions
 Nutrition plays an important role in an endurance
athlete’s ability to perform
 Proper nutrition in combination with sound and
proven training techniques can help endurance
athletes to maximize their genetic abilities
 Certain nutritional supplements have not
demonstrated any performance benefit in studies

27. Conclusions
 Certain nutritional supplements can have
potentially dangerous side effects
 Further legislation is needed to address the
dangers of some nutritional supplements
 Professionals in the community need to be
resources of good information for athletes,
parents and coaches
 Physicians
 Physician assistants
 Nurse practitioners
 Athletic trainers
 School nurses
 Dieticians

28. References
 Bemben MG, Bemben DA, Loftiss DD, Knehans AW. Creatine supplementation during
resistance training in college football athletes. Med Sci Sports Exerc 2001;33(10):1667-73.
 Bemben MG, Tuttle TD, Bemben DA, Knehans AW. Effects of creatine supplementation on
isometric force-time curve characteristics. Med Sci Sports Exerc 2001;33(11):1876-81.
 Bosco C, Tihanyi J, Pucspk J, Kovacs I, Gabossy A, Colli R, Pulvirenti G, Tranquilli C, Foti
C, Viru M, Vira A. Effect of oral creatinine supplementation on jumping and running
performance. Int J Sports Med 1997;18(5):369-72.
 Fuentes RJ and Rosenberg JM. Athletic Drug Reference ’99. Durham (NC): Clean Data,
Inc.; 1999.
 Green G. Innovations in Drug Testing. Presented at the American Medical Society for
Sports Medicine Annual Meeting, Orlando (FL), April 2002.
 Haller CA, Benowitz NL. Adverse cardiovascular and central nervous system events
associated with dietary supplements containing ephedra alkalloids. N Engl J Med
2000;343(25):1833-8.
 Jackson C. Vitamin and Mineral Use and Controversies for Strength Training. Presented at
American College of Sports Medicine Annual Meeting, St. Louis (MO), May 2002.
 Jones AM, Atter T, Georg KP. Oral creatine supplementation improves multiple sprint
performance in elite ice-hockey players. J Sports Med Phys Fitness 1999;39(3):189-96.
 Kreider RB, Ferreira M, Wilson M, Grindstaff P, Plisk S, Reinardy J, Cantler E, Almada AL.
Effects of creatine supplementation on body composition, strength and sprint performance.
Med Sci Sports Exerc 1998;30(1);73-82.
 Mihic S, MacDonald JR, McKenzie S, Tarnopolsky MA. Acute creatine loading increases
fat-free mass, but does not affect blood pressure, plasma creatinine, or CK activity in men or
women. Med Sci Sports Exerc 2000;32(2):291-96.

29. References
 Romer LM, Barrington JP, Jeukendrup AE. Effects of oral creatine supplementation on high
intensity, intermittent exercise performance in competitive squash players. Int J Sports Med
2001;22(8):546-52.
 Samenuk D, Link MS, Homoud MK, Contreras R, Theohardes TC, Wang PJ, Estes NA 3rd.
Adverse cardiovascular events temporally associated with mahuang, an herbal source of
ephedrine. Mayo Clin Proc 2002;77(1):7-9.
 Schanzer W. Analysis of Non-Hormonal Nutritional Supplements for Anabolic-Androgenic
Steroids – An International Study. Available through the official website of the International
Olympic Committee 2002.
 Schilling BK, Stone MH, Utter A, Kearney JT, Johnson M, Coglianese R, Smith L, O’Bryant
HS, Fry AC, Starks M, Keith R, Stone ME. Creatine supplementation and health variables:
a retrospective study. Med Sci Sports Exerc 2001;33(2):183-88.
 Syrotuik DG, Game AB, Gillies EM, Bell GJ. Effects of creatine monohydrate
supplementation during combined strength and high intensity training on performance. Can
J Appl Physiol 2001;26(6):527-42.
 Tarnopolosky MA, Parise G, Yardley NJ, Ballantyne CS, Olatinji S, Phillips SM. Creatine-
dextrose and protein-dextrose induce similar strength gains during training. Med Sci Sport
Exerc 2001;33(12):2044-52.
 Poortmans JR, Auquier H, Renaut V, Durussel A, Saugy M, Brisson GR. Effect of short-
term creatine supplementation on renal responses in men. Eur J Appl Physiol Occup
Physiol 1997;76(6):566-67.
 Rico-Sanz J, Mendez Marco MT. Creatine enhances oxygen uptake and performance
during alternating intensity exercise. Med Sci Sports Exerc 2000;32(2):379-85.
 Wallace B. Hormone “Supplements” and the Strength Athlete. Presented at American
College of Sports Medicine Annual Meeting, St. Louis (MO), May 2002.

30. References
 Tarnopolosky MA, MacLennan DP. Creatine monohydrate supplementation enhances high-
intensity exercise performance in males and females. Int J Sport Nutr Exerc Metab
2000;10(4):452-63.
 Vahedi K, Domigo V, Amarenco P, Bousser MG. Ischaemic stroke in a sportsman who
consumed MaHuang extract and creatine monohydrate for body building. J Neurol
Neurosurg Psychiatry 2000;68(1):112-3.
 Vandebuerie F, Vanden Eynde B, Vandenberghe K, Hespel P. Effect of creatine loading on
endurance capacity and sprint power in cyclists. Int J Sports Med 1998;19(7):490-95.
 Volek J. Nutritional Practices for Resistance Training. Presented at American College of
Sports Medicine Annual Meeting, St. Louis (MO), May 2002.
 Volek JS, Mazzetti SA, Farquhar WB, Barnes BR, Gomez AL, Kraemer WJ. Physiological
responses to short-term exercise in the heat after creatine loading. Med Sci Sports Exerc
2001;33(7):1101-8.
 Volek JS, Duncan ND, Mazzettti SA, Putukian M, Gomez AL, Kraemer WJ. No effect of
heavy resistance training and creatine supplementation on blood lipids. Int J Sports Nutr
Exerc Metab 2000;10(2):144-56.
 NCAA. 2001-02 NCAA Banned-Drug Classes. Available at URL:
[http://ncaa.org/sports_sciences/drugtesting/banned_list.html].
 Zaacks SM, Klein L, Tan CD, Rodriguez ER, Leikin JB. Hypersensitivity myocarditis
associated with ephedra use. J Toxicol Clin Toxicol 1999;37(4):485-9.
 Nadir A, Agrawal S, King PD, Marshall JB. Acute hepatitis associated with the use of a
Chinese herbal product, ma-huang. Am J Gastroenterol 1996;91(12):1436-8.
 http://www.usdoj.gov/ndic/pubs11/12620/steroids.htm