NS 425NS 425Sports NutritionSports Nutrition

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CarbohydratesCarbohydratesThe Master Fuel

Unit 3Amy Habeck, RD, MS, LDN

RecognitionRecognition

The Master FuelThe Master Fuel

Why is carbohydrate called the Master Fuel?

The Master FuelThe Master Fuel

Stored in muscleOxygen not neededLess oxygen than fat

Carbohydrate FunctionsCarbohydrate Functions

Most important source of energyUsed in fat metabolismHigher intensity activities

◦Anaerobic activities-How many macronutrients can be utilized for energy in the absence of oxygen?

Spares muscle tissueNervous system

Examples of carbohydratesExamples of carbohydrates

FiberOligosaccharidesSucroseSimple sugars

◦Mono and disaccharides Glucose Fructose sucrose

Carbohydrate NeedsCarbohydrate Needs

RDA: At least _____ gm◦31 tsp sugar◦Large apple, 1 c Cheerios, 1 c milk, 1 c o.j., slice ww

toast = 93 gmAMDR: ______% of daily calories

◦275 gm for a 2000 calorie diet◦NHANES III – 51% of daily calories

Athletes◦______ gm/kg◦_______% of calories for long-duration and high-

intensity training

Carbohydrate NeedsCarbohydrate Needs

RDA: At least 130 gm◦31 tsp sugar◦Large apple, 1 c Cheerios, 1 c milk, 1 c o.j., slice ww

toast = 93 gmAMDR: 45-65% of daily calories

◦275 gm for a 2000 calorie diet◦NHANES III – 51% of daily calories

Athletes◦6-10 gm/kg◦70-75% of calories for long-duration and high-

intensity training

The Carbohydrate ChallengeThe Carbohydrate Challenge

Consume best sourcesEstablish ideal practices

Improve sport performance◦ Type and timing

Recovery and maintenance

Athletes and Carbohydrate IntakeAthletes and Carbohydrate Intake

What factors are important to consider when determining an athlete’s carbohydrate needs?

Athletes and Carbohydrate IntakeAthletes and Carbohydrate Intake

Body weightEnergy needsMetabolic demands of their sportStage of training or competition schedule

Net CarbsNet Carbs

Net carbs = total carbs – fiber◦Reflective of nutritive carbohydrates◦Controversial/theoretical

Not regulated on labels◦Will likely be addressed soon

Net CarbsNet Carbs

Do you look at net carbs on labels?Do you calculate it if it isn’t there?Do you think it is important for people to

know?

Glycemic Index & Glycemic LoadGlycemic Index & Glycemic Load

How many of you have heard of GI and GL prior to this class?

Has anyone heard of it outside of nutrition classes?

Glycemic IndexGlycemic Index

Indicates how much a certain food raises blood glucose levels when consumed in isolation◦50 gm test◦Given as a percentage of rise in blood glucose

from a reference food at 2 hours Glucose White bread

Used to help identify the glucose response of a single food

Goal of using GIGoal of using GI

Optimize carbohydrate availability before, during and after exercise◦Low GI meal prior to exercise

2 hour cycle – lower glucose at 120 min Exercise to exhaustion – lower glucose at 120 min

Factors Affecting GIFactors Affecting GI

What factors affect glycemic index in food?

Factors Affecting GIFactors Affecting GI

Type of carbohydrateFiber contentProtein and fat contentLiquid vs solidTiming of the mealCombination of food consumed at same

timeTotal amount of carbohydrate consumed

GI and Training

Low GI before event

Moderate to high GI during event to quickly deliver carbohydrate to muscles

High GI after event to replete glycogen

Food Item GI High/Low

Sugar 65 Medium

Gatorade 89 High

Orange juice 52 Low

Glycemic LoadGlycemic Load

Overall glycemic effect(GI x Carbohydrate content/serving)/100More practical measure

Are GI & GL Useful?Are GI & GL Useful?

Do you think GI and GL are useful measures to have available to consumers?

How could you use it when working with athletes?

Simple SugarsSimple Sugars

What are some of the negative effects of elevated consumption of simple sugars?

Simple SugarsSimple Sugars

Dental cariesWeight gainCalorie-dense, nutrient-poor foodsHyperinsulinemia

◦Cardiovascular diseaseHyperglycemia

◦Vascular disease◦Neurological disease

Simple vs Complex Simple vs Complex CarbohydratesCarbohydrates

Glycemic index and type of carbohydrate not directly relatedSimple and complex carbohydrates differ in vitamin, mineral, fiber and phytochemical content

Type of carbohydrate not predictive of GI

Fructose has a lower GI than most starches

Many complex carbohydrates have a medium-high GI

Glycogen DepletionGlycogen Depletion

Workouts become harder to completeMental focus is more difficultEnergy levels dropMuscles feel fatigued

Endurance TrainingEndurance Training

Increases the body’s ability to use fats for energy

Helps to spare glycogenDelays fatigueImproved endurance performance

Carbohydrates and TrainingCarbohydrates and Training

Several days of high carb prior to intense training session or competition◦Increase glycogen stores prior to exercise

What type of training and carbohydrate What type of training and carbohydrate intake is prescribed for each type of loading?intake is prescribed for each type of loading?

Carbohydrate Loading Daily Loading

Carbohydrate Loading vs Loading Carbohydrate Loading vs Loading as a Component of Daily Trainingas a Component of Daily Training

Carbohydrate Loading Daily Loading

Personal ExperiencePersonal Experience

Have you practiced carbohydrate loading before an event?

Would you recommend it based on personal experience or readings?

Eating Before an EventEating Before an Event

4-24 hours before event◦60-70% carbohydrate◦Tops off glycogen

Zero to 4 hours prior◦Low GI◦Easily digested◦Moderate to low in fiber

Eating During ExerciseEating During Exercise

CarbohydratesBegin soon after initiation

Eating After ExerciseEating After Exercise

Replace muscle and liver glycogen◦Can take 20+ hours

Optimal glycogen replacementNeed about 1 gm/kg body weight

Meggan, p. 63Meggan, p. 63

15-year-old soccer playerSpeed and endurance athleteDecreased carbohydrate intake from 65% to

40% to decrease weightFeeling fatigued during 2-3 hour practice

◦Drinks o.j. during practice to rehydrate◦Results in nausea and intestinal cramping

What are the possible causes of Meggan’s earlier-than-usual fatigue?

Suggestions?

High Fiber DietHigh Fiber Diet

Prevent high cholesterolPrevent diverticular diseaseRegulate blood sugarPrevent and treat constipationProduces an increased satiety level

Dietary FiberDietary Fiber

Dietary fiber◦Non-digestible carbohydrates- no calories◦Soluble and insoluble◦Found in oat and wheat bran, plant CHO, and

lignins◦May help lower cholesterol◦Decreases intestinal transit time

Fiber and ConsumersFiber and Consumers

Do you think the NLEA method of listing fiber is confusing to consumers?

How would you change the information provided to clarify fiber content and needs for consumers?

CLA/Final Project CLA/Final Project Unit 3Unit 3

Explain the aerobic and anaerobic systems as they pertain to your athlete and sport.

Complete this portion of the project as a 1–2 page paper with references.

The student explains the aerobic and anaerobic systems as pertaining to their athlete and sport.

Use APA format◦Title page◦Cite references (in-text and reference page)

Unit 3 ExamUnit 3 ExamYou Might See…You Might See…

How does a plant form carbohydrates?What is glycemic index and how is it

used?Carbohydrate recommendations

surrounding competition

FarewellFarewell

Thank you for your kind attention and participation

Good Luck on the Quiz!Questions?