Here are the answers to your questions: 1. The recommended levels of protein intake for athletes are 1.0-1.7 g/kg/body weight per day. 2. The recommended additional vitamin antioxidants for athletes are vitamin E and C, which have slightly higher needs due to their antioxidant properties. 3. For a female athlete to reestablish monthly menstruation, she should focus on increasing calcium intake through dairy products like yogurt and cheese, and ensuring irregularities in menstruation/amenorrhea do not compromise bone health through extra calcium intake alone. Regular physical activity and maintaining a healthy body fat level of 17-28% are also important. 4. Sports drinks containing carbohydrates

1. SPORTS MEDICINE
SPORTS NUTRITION

2. What is expected of you
 Understand the following
a)energy sources for muscles
b)dietary recommendations for athletes
B)pre-event nutrition
C) recovery nutrition
D) nutrition and the injured athlete

3. 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

4. Benefits of Physical Activity

5. Nutrition and Physical Activity
 Only 15% of adults are regularly physically
active (U.S.)
NUTRITION (intake)
Physical Performance
Nutrient Use

6. Beginning an Exercise Program
 Start out slowly
 Vary your workout—Make it fun
 Include others—Keep accountable (notebook/log)
 Set attainable goals
 Set aside specific time (daily or weekly)
 Reward yourself
 Focus on long-term and not on occasional
setbacks

7. 2005 Dietary Guidelines for
Americans
 30 minutes/day physical activity
– Reduce risk of chronic disease
 60 minutes/day physical activity
– Manage body weight and prevent weight gain
 90 minutes/day physical activity
– Sustain considerable weight loss

8. 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

9. 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

10. 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

11. 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

12. Glucose Utilization

13. 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”
– Depleted glycogen
– Work at ~50% of maximal capacity

14. ATP Formation

15. 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

16. 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

17. 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)

18. 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)
 Resistance exercise uses protein less
 Average diet
– Provides ample amount of these amino acids
– Supplements not needed (usually)

19. Fuel Use During Physical Activity

20. 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%

21. 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

22. Carbohydrate Loading
Events lasting longer than 60-90
minutes
Maximize glycogen stores
Tapering of exercise while
increasing carbohydrate intake
Additional water weight

23. Fat Needs
 ~35% of total kcal (runner, otherwise
much less . .
 Rich in monounsaturated fats
 Limit saturated fats
 Limit trans fat

24. 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

25. Current Protein Recommendations

26. Vitamins and Minerals
 Vitamin E and C
– Slightly higher needs
– Antioxidant properties
 Thiamin, riboflavin, vitamin B-6, potassium,
magnesium, iron, zinc, copper, and
chromium needs
– May also be higher (role in metabolism or
sweat)
 Increase intake of fruits and vegetables
Vitamin C

27. Iron Needs
 Iron deficiency 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

28. Calcium Needs
 Restriction of 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

29. Fluid Needs
 Needs of average adults
– 9 cups per day for women
– 13 cups per day for men
 Athletes need more (depending on sweeting
 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

30. 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 C per hour
 Humidity interferes with sweat production
 Dehydration decreases endurance, strength,
performance
 Signs: Profuse sweating, headache, dizziness,
nausea, weakness, visual disturbances

31. 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

32. 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

33. Sports Drinks For
Endurance Exercise
 Recommended for activity > 60 minutes
– Help maintain blood glucose level and blood
volume
– Delay “bonking”
 Supply electrolytes: Na, K, P, Cl
 <60 minutes: Water adequate:
– Nutrients are easily replaced by diet

34. 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
– Toxicities possible with overuse

35. 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

36. Recovery Meal
 Carbohydrate-rich meal within 2
hours after endurance event
– Glycogen synthesis is the greatest
– 1-2 gm CHO/kg body weight
 Choose high glycemic index foods
 Aim for 3:1 carbohydrate-to-protein
 Fluid and electrolyte replacement

37. 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

38. 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

39. ERGOGENIC AIDS
 Describe ergogenic aids and give
examples

40. Ergogenic Aids

41. Ergogenic Aids

42. A resounding Yes . . .
Androsterone
Testosterone
O
OH
H3 C
H3 C H3 C
H3 C
HO

43. Hydroxycut recall
hydroxycitric acid
Laboratory and animal studies of HCA
have produced results that indicate a potential
for modulation of lipid metabolism
Shara et al., 2003, Mol. Cell. Biochem. 254 (1-2): 339–46
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

44. QUESTIONS
 What are the recommended levels of protein in
g/kg/body wt. for athletes?
 What are the recommended additional vitamin
antioxidants required for athletes?
 What can the female athlete do to her diet and
physical activity level to reestab. Monthly mensus?
 After what duration of exercise are Sports drinks
considered necessary for replenishment of glucose
and electrolyte stores?