Sports Nutrition: Unit 1

Name the 6 essential nutrients.

Carbohydrates

Proteins

Fat

Vitamins

Minerals

Water

Carbohydrates

1. Composed of sugars (glucose)

2. Sugars are compounds made of carbon, hydrogen, and oxygen

3. Provides the body with energy (4 kcals/gram)

4. Found in many foods, mostly in grains, fruits, and vegetables

Proteins

1. Composed of essential and nonessential amino acids

2. Made of carbon, hydrogen, oxygen, and nitrogen

3. Involved in the growth and repair of body tissues

4. Provide some energy

5. Found in many foods, mostly dairy and various animal meats

Fats

1. Also known as lipids

2. Serve as a concentrated form of energy (9 kcals/gram)

3. Provide structure to body tissues (nerves and cell membranes)

4. They are concentrated in foods such as butter, oils, and meats

Vitamins

1. Composed of carbon and other elements

2. Must be obtained from diet

3. Are essential to at least one vital process

4. Are found in nearly all foods, particularly fruits and vegetables

   1. Water Soluble: B, C

   2. Fat Soluble: A, D, E, K

Minerals

1. Composed of elements other than carbon

2. Serve important structural, electrical, and chemical roles in the boy

   1. Major (requirements > 100 mg/day): Calcium, Sodium, Potassium, Chloride, and others

   2. Minor (requirements < 100 mg/day): Iron, Zinc, Copper, Iodine, and others

Water

1. 55-60% of body weight

2. Essential for life

   1. Temperature regulation

   2. Lubrication

   3. Transport

What is sports nutrition?

• A specialization within the nutrition field

• Requires a knowledge of both nutrition and exercise science

• Goes beyond general health and wellness

• Sports nutrition involves:

  • Providing energy for physical activity and/or competition

  • Providing nutrients for repair, recovery, and adaptation to physical training

  • Designing practical dietary strategies to achieve the above goals

What is an RD/RDN?

• A registered dietitian or registered dietitian nutritionist

• Approximately 90,000 in the US

• Work in a variety of settings

  • Hospitals

  • Universities

  • Food service

  • Consulting

  • Public Health organizations

How does the body produce energy?

• Carbohydrates, fats, and proteins are metabolized

• Energy is released

• Adenosine triphosphate (ATP) is formed

• ATP is the “direct” source of energy for muscle activity

Recommended Dietary Allowances (RDA)

• Developed in 1941

• U.S. National Academy of Sciences

Dietary Reference Intakes (DRIs)

• Expands the RDA

• Includes other quantities (Estimated Average Requirement, Adequate Intake, and Tolerable Upper Intake Level)

What are the Dietary Guidelines for Americans?

• Developed by the US DHHS and the USDA

• Provide science-based advice regarding dietary and physical activity habits that can promote health and reduce the risk of disease

• Athletes can benefit from implementing the guidelines for health and performance

Nutrition labels must include

• Statement of identity - Commonly used name or descriptive title of the food product

• Net contents - Found on the front of the label along the bottom edge, indicates the quantity of food in the package, expressed in weight, volume, or count

• Manufacturer information - Usually in small print, located near the ingredient list

• Ingredients list - Ingredients are listed in descending order of predominance based on weight, used to evaluate the nutritional quality of food, and to avoid certain additives or foods to which athletes may be allergic or intolerant

• Nutrition facts panel - Serving size information, total calories, fat, carbohydrate, and protein content, vitamin and mineral information, percent daily values (%DV)

Nutrient claims

Highlight food characteristics

Health claims

Describe potential health benefits

What to consider when developing an athlete’s nutrition plan?

• Health history

• Energy demands of the sport

• Total weekly training and competition time

• Livings arrangements

• Access to food

• Travel schedules

Goals of sports nutrition?

• Optimal Performance

• Recovery

• Injury Prevention

What happens to nutrients after they are ingested?

• Digestion

• Absorption

• Transport

• Assimilation/energy production

Anatomy of the digestive system

• Mouth

• Salivary glands

• Esophagus

• Stomach

• Pancreas

• Liver

• Gallbladder

• Small intestine

• Large intestine

• Rectum

• Anus

Salivary glands

• Salivary glands

  • Parotid

  • Sublingual

  • Submandibular

• Secrete saliva

  • Moistens food

  • Contains enzymes

Stomach

• Muscular organ

• Primary function: Digestion

• Major secretions

  • Hydrochloric acid

  • Mucus

  • Digestive enzymes

Small intestine

• Duodenum

  • Majority of digestion occurs here

• Jejunum

  • Little digestion

  • Absorption

• Ileum

  • Absorption

Surface of small intestine

• Convoluted interior

• Villi

• Microvilli

• Increased surface area for absorption

Large intestine

• Colon

  • Ascending, Transverse, Descending

• Rectum

• Anus

• Some absorption

  • Water

  • Sodium

  • Chloride

  • Potassium

  • Vitamin K

Mechanisms for nutrient absorption

• Passive diffusion

• Facilitated diffusion

• Active transport

• Endocytosis

Passive diffusion

Some substances easily move in and out of cells, either through protein channels or directly through the cell membrane

Facilitated diffusion

• Some substances need a little assistance to enter and exit cells

• The transmembrane protein helps out by changing shape

Active transport

Some substances need a lot of assistance to enter cells. Similar to swimming upstream, energy is needed for the substance to penetrate against an unfavorable concentration gradient

Endocytosis

• Cells can use their cell membranes to engulf a particle and bring it inside the cell

• The engulfing portion of the membrane separates from the cell wall and encases the particle in a vesicle
  

D, A, & PA: Carbohydrates

• Digestion

  • Mouth - Mastication (chewing) and amylase

  • Stomach - Churning and Acid

  • Small intestine - Sugar enzymes

  • Large intestine - Bacteria

• Absorption

  • mostly in small intestine

    • Facilitated diffusion: Fructose

    • Active transport: Glucose and galactose

• Post Absorption

  • Transport via blood

  • Cellular uptake

    • Insulin

    • Glucose transporters

  • Fates

    • Storage

    • Conversion

    • Energy

D, A, & PA: Proteins

• Digestion

  • Mouth - Mastication (chewing)

  • Stomach - Churning and Acid denaturation

  • Small intestine - Protease and peptides

• Absorption

  • Small intestine

    • Facilitated diffusion

    • Active transport

• Post Absorption

  • Transport via blood

  • Part of amino acid pool

  • Fates

    • Body proteins

    • Conversion

    • Energy

D, A, & PA: Fats

• Digestion

  • Mouth - Mastication (chewing) and lingual lipase

  • Stomach - Gastric lipase

  • Small intestine - Bile and Pancreatic lipase, Micelle formation

• Absorption

  • Small intestine

    • Passive diffusion

  • Very little fat makes it into the large intestine

    • Steatorrhea

    • Chron’s disease

    • Cystic fibrosis

• Post Absorption

  • Transport via lymph

  • Chylomicrons via blood

  • Cellular uptake - Lipoprotein lipase

  • Fates

    • Storage

    • Energy

Cellular Protein Synthesis

• Transcription

  • DNA

  • mRNA

• Translation

  • Transfer RNA

  • Amino acids

________ cases release from foods

Digestion

_______ occurs in the small and large intestines

Absorption

What is energy? 

• Enables our bodies to perform work

• No shape

• No mass

• Our bodies rely on chemical energy

What is the body’s source of energy?

• Macronutrients

• Adenosine triphosphate (ATP)

ATP

• Body’s energy source

• Two high-energy bonds

• Other phosphates

  • ADP

  • AMP

Name the three energy systems

• Phosphagen

• Anaerobic

• Aerobic

Phosphagen system

• Stores high-energy phosphates (ATP, Creatine Phosphate (CP))

• Immediate energy system (sprinting, weight lifting)

• Energy system complexity: one-step process

• Maximal rate of ATP production: Very fast

• Capacity to make ATP: Very limited

• Lag time to increased ATP production: Instantaneous 

• Metabolic Pathways: None

Anaerobic energy system

• Carbs only

• No oxygen needed

• Anaerobic glycolysis

• Continued production of ATP for up to 3 minutes

• Intermittent, high-intensity bursts of activity (800m)

• Lactate Threshold

  • Production exceeds clearance

  • Exercise beyond threshold → more production → Reliance on anaerobic glycolysis (CHO)

  • Oxygen must be present to continue

  • Can improve with training

• Energy system complexity: 12-step-process

• Maximal rate of ATP production: Fast

• Capacity to make ATP: Limited

• Lag time to increased ATP production: Seconds

• Metabolic Pathways: Glycolysis

Aerobic energy system

• All macronutrients used

• Oxygen needed

• Anaerobic glycolysis

• Can improve with training

• Energy system complexity: Very high

• Maximal rate of ATP production: Very slow

• Capacity to make ATP: Unlimited

• Lag time to increased ATP production: Minutes

• Metabolic Pathways:

  • Beta-oxidant (fat)

  • Glycolysis (carbohydrate)

  • Deamination (protein)

  • Citric acid cycle

  • Electron transport chain

Lactate

formed during exercise released into bloodstream and metabolized by cells with oxidative capacity

Cori cycle

liver converts lactate to new glucose (gluconeogenesis)

Why does lactate production increase in intensity during exercise?

Krebs Cycle moves too slowly, pyruvate builds up, converts to lactate (insufficient O₂ supply)

Two Main Forms of the Lactate Shuttle

• Intracellular Shuttle: Lactate moves from the cell's cytoplasm into its own mitochondria to be oxidized for energy.

• Cell-to-Cell Shuttle: Lactate is transported between different cells and tissues (e.g., from highly active muscle fibers to less active ones, the heart, or the brain).

Lactate Dehydrogenase (LDH)

The enzyme that interconverts pyruvate and lactate, crucial for regenerating NAD+ to sustain glycolysis.

Monocarboxylate Transporters (MCTs)

Specialized proteins on cell membranes that facilitate lactate's movement into and out of cells.

Why the Lactate Shuttle is Important?

• Efficient Energy Transfer: Allows for rapid distribution of carbohydrate-derived energy throughout the body.

• Preferred Fuel Source: Many oxidative tissues (like the heart and brain) readily use lactate as a primary fuel, sometimes even preferring it over glucose.

• Signaling Molecule: Lactate also acts as a signal, influencing gene expression and cellular adaptations to exercise.

Longer-lasting sprints (800m)

Mainly anaerobic + phosphagen and aerobic

Intensive Activity (100m)

Phosphagen system

Longer-lasting activity (mile)

Mainly aerobic + anaerobic

Longer-lasting with low intensity

Aerobic

Simple Carbohydrates

• Monosaccharides

  • Glucose

  • Galactose

  • Fructose

• Disaccharides

  • Sucrose

  • Lactose

  • Maltose

Complex Carbohydrates

• Oligosaccharides

  • Maltodexterin

  • Corn syrup

  • Chain 3-10 sugars long

• Polysaccharides

  • Starch

  • Glycogen

  • Chains >10 sugars long

Other Polysaccharides

• Dietary fiber

  • Nondigestible

  • Plant sources

  • Soluble versus insoluble

• Functional fiber

  • Nondigestible

  • Commercially produced or isolated form

About Artificial Sweeteners

• Non-nutritive

• Nutritive

• Sweeter than sucrose

• Must have FDA approval

• Have GRAS status

Name Artificial Sweeteners

• Saccharin

• Aspartame

• Acesulfame-K

• Sucarlose

• Stevia

• Sugar alcohols

High Protein diet may result in the production of 

Urea

Basing Protein Intake off of 

• Activity

• Caloric Intake based on Diet

Source for Omega 6

Source for Omega 3

Essential Fatty Acids

• Omega 3

• Omega 6

AHA recommendations for refined sugar

most adult women limit added sugar to no more than 100 calories (about 6 teaspoons) per day, and most adult men to no more than 150 calories (about 9 teaspoons) per day

Carb recommendations before, during, and after

Before: 1-4 grams of carbohydrates per kilogram of body weight. 

During: 30-60 grams of carbohydrates per hour. 

After: 1.0-1.2 g/kg body weight of high-glycemic carbohydrates. 

How much energy we store (cals)

About 80-85% in fat

Cholesterols

Lipids (Sterol)

HDL - good

LDL - bad (risk for cardiovascular disease)

Adequate Carbohydrate Intake

• Replenishes glycogen

• Spares the break down of muscle tissue for energy

Gluconeogenesis

Creation of new glucose

• Lactate

• Glycerol

• Amino Acids

Protein Synthesis

Stimulated when protein is ingested post-workout

Product of Anaerobic System

Lactate

Two Phases of Aerobic System

Krebs Cycle

ETC

Type 1 muscle fibers (slow twitch)

primary muscle fiber for endurance activities

High oxidant capacity

Type 2 Muscle Fibers (fast twitch)

primary muscle fiber for power based activities

Lower oxidant capacity

Scope of Practice

The boundaries in which someone can work within

Complimentary Protein Pair 

When consumed together, a complete amino acid profile is formed e.g. rice and beans

energy stored in

fat

glycogen

atp

phosphocreatine

Classification of protein

Complete e.g. animal products

Incomplete (missing an amino acid) e.g. plant products

Prescribing Carbs for Athletes

3-12 grams/kg of bodyweight (carbs)

Prescribing Protein for Athletes

1.2-2 grams/kg of bodyweight (protein)

Branch Chain Amino Acids

Can be used directly for energy

Essential Amino Acids

Lucine

Hycolucine

Bayline

Branch Chain Amino Acids

Fiber

• Appetite Regulation

• Weight Loss

• Gut Microbiome

• Reduces risk for heart disease, cancer, etc.