Nutrition SDL #2: Sports Nutrition

Question 1

What % of weight does muscle account for in athletes?

Answer 1

40-50%

Question 2

What do slow twitch fibers use for energy?

Answer 2

FAs and glucose in blood through oxidative phosphorylation

Question 3

What do fast twitch fibers use for energy? Is this efficient?

Answer 3

Glycogen, not efficient because anaerobic breakdown uses only 6% of the energy potential of glycogen because going so fast

Question 4

Describe the order in which energy is used in muscles.

Answer 4

1. ATP stores (run out in 2-3 sec)
2. Creatine phosphate (lasts 10 seconds)
3. Fuel metabolism (glycogen or fat)

Question 5

What does creatine phosphate do to recharge energy supplies?

Answer 5

Transferring its phosphate to ADP

Question 6

How does FA oxidation vary in slow twitch muscles during different levels of effort?

Answer 6

Stays constant

Question 7

What is the main source of energy for muscles at rest or during light to moderate exercise?

Answer 7

Fat

Question 8

When is glucose used in slow-twitch muscles instead of fat?

Answer 8

When the energy demands exceed 300-400 kcal/hr

Question 9

What large molecule does FA beta oxidation require to proceed? Why?

Answer 9

Glucose: provides intermediates for Krebs cycle

Question 10

How long does it take for glycogen stores in a muscle to be depleted?

Answer 10

Hours

Question 11

How many calories are provided by 1 g of fat?

Answer 11

9 kcal

Question 12

What is the most high density energy source?

Answer 12

Fat

Question 13

What are the 7 cofactors necessary for beta oxidation of fats and glycolysis?

Answer 13

1. Thiamin: B1
2. Riboflavin: B2
3. Niacin
4. Pantothenate
5. Biotin
6. Iron
7. Magnesium

Question 14

What kind of patients may lack enough iron?

Answer 14

Young women and vegetarians

Question 15

What are fats converted to in beta oxidation?

Answer 15

Acetyl CoA

Question 16

How many calories are provided by 1 g of glucose?

Answer 16

4 kcal

Question 17

Can fats and proteins be used in anaerobic metabolism?

Answer 17

NOPE

Question 18

What is the main pathway for glucose to replenish the intermediates needed for FA beta oxidation?

Answer 18

Biotin dependent carboxylation of pyruvate

Question 19

Why is it best for athletes to eat carbs before practice? What amount and when?

Answer 19

To spare glycogen stores

100-140 g of carbs 1-3 hrs before

Question 20

What is a negative side effect of oxidative phosphorylation (ETC)? How to prevent the negative side effects?

Answer 20

ROS leak

Antioxidants (fruits/vegetables/Vitamins C&E), selenium containing enzymes, carotenoids

Question 21

What is the ideal amount of carbs to eat to replenish glycogen stores?

Answer 21

100 g/400 kcal of energy expended: 50 g/2 hrs

Question 22

What are the best kinds of foods to eat to replenish glycogen stores?

Answer 22

High glycemic index foods: rapidly absorbed carbs

Question 23

What can excessive glycogen intake cause?

Answer 23

Slow muscle action, decrease in initial speed, cramps

Question 24

What can inadequate repletion of glycogen stores cause?

Answer 24

Sluggishness and poor performance

Question 25

What should be consumed during a competition or race?

Answer 25

30-60 g of carbs per hour

Question 26

Other than carbs, what else is needed to recover from exercise?

Answer 26

1. Proteins for muscle repair 2. Vitamin B6 3. Magnesium 4. Manganese

Question 27

How much protein a day needed for endurance athletes?

Answer 27

1.2-1.4 g/kg

Question 28

How much protein a day needed for strength athletes?

Answer 28

1.6-1.7 g/kg

Question 29

How many carbs a day recommended for endurance athletes? What does the highest number of the range correspond to?

Answer 29

6-10 g/kg 10 g/kg = carb loading

Question 30

What does Total Energy Expenditure (TTE) depend on? 5 factors. Which one is the most variable factor?

Answer 30

1. Age 2. Weight 3. Height 4. Gender (aka muscle mass) 5. Physical activity (most variable)

Question 31

What does the Daily Calorie Needs Estimator use?

Answer 31

Dietary Reference Intakes (DRIs) formula

Question 32

What is the dietary protocol of cancer survivors?

Answer 32

Low fats and high fruits/vegetables

Question 33

Other than athletes, what other individuals have increased dietary needs?

Answer 33

1. Pregnant women 2. Women who are breast feeding 3. Sick people

Question 34

When are Metabolic Equivalents (METs) used?

Answer 34

Professional athletes

Question 35

What is the METs formula?

Answer 35

Energy Expenditure = kg x hrs x MET x 1.05 kcal (needs to be for every activity in a day

Question 36

Do the EERs and DCNEs take into account weight loss for overweight people?

Answer 36

Nope

Question 37

What does a decrease in 500 kcal/day correspond to for weight loss?

Answer 37

Loss of 0.45 kg/week

Question 38

What % of calories should fat comprise of?

Answer 38

20-35%

Question 39

What % of calories should carbs comprise of?

Answer 39

55%

Question 40

What is the first step in determining if a patient needs a supplement?

Answer 40

Obtain detailed dietary history