SPORTS NUT: ENERGY SYSTEMS

sports nutrition

● A specialty area of study and practice within the field of nutrition that partners closely with the study of human body and exercise science. ●Application of nutrition knowledge to a practical daily eating plan focused on:

(1) providing fuel for physical activity

(2)facilitating repair and rebuilding process following hard physical work,

(3) and optimizing athletic performance in competitive events while

(4)also promoting overall health and wellness

Athletes

any individual who is regularly active, ranging from fitness enthusiast to competitive amateur or professional

differences may exist in specific nutrient needs along this designated spectrum of ____ - the challenge of individualizing sports nutrition plans

physical fitness

set of abilities an individual possesses to perfrom specific types of physical activity

ability of a person to carry out the daily task without feeling overly tired

sports nutritionist

To be considered an “expert” in sports nutrition, a professional must obtain the appropriate education and certification background as well as hands-on experience working with athletes.

An individual whose professional practice is based upon information, guidelines, or interventions that have been shown through research to be safe and effective

homeostasis

The human body is a dynamic organism capable of regulating the environment within itself - a process called _____

Exercise physiology

the study of these alterations (temperature, attitude, and participation in physical activity or exercise) and the response to the exercise

alterations that include repeated exercise and long-term training

Adenosine triphosphate

the biologically usable form of energy in the body

skeletal muscles

all movement requires an increased energy demand on ___

fatigue

ensues if the body would have difficulty with the increased energy demand

Refers to impairment or inability to produce force at the level of the muscle

Chemical energy

Energy that is released as the bonds holding chemicals together are broken. In the human body, the foods ingested provide chemical energy to make ATP, which is the ultimate source of chemical energy in the body

Exogenous sources

energy gained from foods and beverages

If your ____ carbohydrate is not consumed or empty already→your glycogen stores are also depleted.

Endogenous Sources

energy gained from stored substrates (stored fat and energy)

energy systems

Limited ATP is stored in the body. The body must

generate ATP to meet the demands of cellular

metabolism, especially muscle contraction during

exercise.

○ Increased activity = increased ATP demand

○ ATP utilization generates ADP, and a single phosphate

group–must be rephosphorized to ATP.

anaerobic, aerobic, and phosphocreatine system.

Three basic metabolic pathways to generate ATP

mitochondria

generates ATP

powerhouse

Aerobic Energy System

Energy Systems

Aside from the substrate, you need oxygen. This will result in carbon dioxide and water, which are excreted in the body in the form of exhalation, urine, and sweat.

Anaerobic Energy System

Does not need oxygen, but to produce ATP, it releases lactate. If lactate enters the muscles, it will make your muscles contract more–making it more fatiguing

Adenosine Triphosphate - Phosphocreatine System

○ Most rapid method to produce ATP

○ Anaerobic system used during intensive, explosive movements(tennis service or power lift).

○ Rapid ATP generation but very limited supply (10 seconds)

Benefiits sports such as track and sprint and javelin throw

PC

Creatine Phosphate

A high-energy phosphate stored inside the muscle

Phosphocreatine

A high-energy phosphate stored inside muscle cells. It is also known as creatine phosphate.

Most important key component of ATP system

for immediate energy

Immediate Energy System

The energy system is composed of the high-energy phosphates ATP and creatine phosphate; as a result, it is also known as the phosphagen system.

Of the three energy systems, it can produce ATP at the fastest rate.

Anaerobic Glycolysis

Oxidize one glucose molecule (6 carbon) to form two pyruvic acid molecules (3 carbons).

Aerobic Metabolism

Oxidative Phosphorylation- Breakdown CHO, FAT, and CHON with oxygen

○ Uses Krebs cycle and Electron Transport Chain.

○ ATP supply is limitless as long as macronutrients and oxygen are available.

for endurance athletes

oxidative phosphorylation

Breakdown CHO, FAT, and CHON with oxygen

can produce limitless ATP

Krebs Cycle and Electron Transport Chain.

pathways to breakdown ATP

Crossover Concept

All metabolic systems work concurrently

○ Fatty acid oxidation = more ATP per g/CHO but is a slow process and more Oxygen.106 ATP molecules with16-carbonFA.

○ 6-carbon Glucose Oxidation-32 ATP molecules, less ATP yield but rapid oxidation and can be done without oxygen

Short-term fatigue

Occurs when the intensity rises to levels that disturb our body’s ability to derive energy from our primary exercise fuel substrates: carbohydrate and fat.

○ Caused by accumulation of metabolic products in organic phosphate, lactate; depletion of phosphate; and changes in cellular calcium

Long-term fatigue

Substrate fatigue or “hitting the wall”-- a consequence of glycogen depletion.

○ Dietary CHO absorption and gluconeogenesis cannot keep up with the demand for ATP, and movement must stop

Acute response to excercise

Increased demand of energy in the skeletal muscle during exercise.

● Increased respiration and blood supply to the working muscles and a reduced blood flow to the GI tract.

● This can continue for minutes to hours depending on the intensity of exercise and the condition of the individual.

● In some sports, the increased energy demand relatively constant for an extended time(e.g., marathon) or by periods of high intensity followed by periods of active recovery or rest (e.g.,soccer, tennis).

● The body systems must work together meet the increased energy demands

600

over ___ skeletal muscles in the human body that allows fine and gross movement

muscle fiber

term to describe a muscle cell

each contains organelles and myofibrils

motor unit

a single nerve and the group of muscle fibers it innervates

sacromeres

are responsible for thecontractileproperties of muscles. It also has thin (actin) and thick (myosin) filaments.

sliding filament theory

Activation of the motor unit causes these filaments to “slide” over one another, allowing muscle contraction

type i fibers

Sometimes referred to as Slow-twitch fibers

○ High level of aerobic endurance

○ Use a continuous supply of energy (from CHO and FAT) ○ Allow prolonged muscle contraction for long periods.

○ Used with daily living activities (walking) or lower-intensity events (bike riding or jogging)

type ii fibers

Sometimes referred to as Fast-twitch

○ Poor endurance capacity

○ Work better Anaerobically

○ Further classified as type ll a, type IIx, and type IIc

Strength and power athletes

athletes with a greater proportion of type lla and a smaller proportion of type Ilx fibers.

Endurance athletes

Cardiovascular and Respiratory Response: athletes with a a greater proportion of type I fibers

Rate of respiration

Cardiovascular and Respiratory Response: increases as exercise intensity increases

glycogen

Cardiovascular and Respiratory Response: With longer-term endurance exercise, ____, or its utilization, is more important than the lung-gas exchange

Heart rate

Cardiovascular and Respiratory Response: increases linearly as exercise intensity increases. It plateaus when a maximum rate is achieved.

Steady-state heart rate

Cardiovascular and Respiratory Response: is the optimal delivery of oxygen and nutrients to the muscle.

Lung-gas exchange

Cardiovascular and Respiratory Response: is not a limiting factor in exercise performance.

positive physiological adaptations

Body’s response to physical activity repeated overtime

improved performance.

Appropriate training + proper fueling + adequate rest and recovery

Overtraining/undertraining

≠ desired effect

body composition

Genetics + environmental factors =

Genetics

creates fat patterning and muscularity, but this does not mean these are outside our control

Ectomorph

slenderandtall

○ advantages insports likevolleyball; ifyouhave longerlegs, thenyouwillbefasterinrunning

○ advantage inanysport in relation tospeedor distance

Mesomorphs

slightly rounded upper body

○ heavier individuals that will have the advantage to weight lifting, sumo, swimming

Endomorph

muscular body type

physical stress

Must induce ___ to the system needed for performance gains

progressive overload

Overload the system being trained to have continuous demands.

● E.g.,Bench press from100lbs. for 8 reps to100lbs. for 12-15reps before fatigue.

● Next, one may need to add more weight to reach again the level of fatigue experienced at 8 reps.

● Other ways to reach fatigue are to increase the number of sets per exercise and decrease the rest period between sets

Variation/peridization

Training in smaller periods based on the desired outcomes.

● Allows for the needed training intensity while working inadequate rest and recovery to prevent overtraining

Macrocycles

monthly periodization

Mesocycles

weekly periodization

Microcycles

individual training

Block periodization

Training blocks

○ Individualized on the desired sports or event

○ A Small number of blocks at one time (3-4) for a few weeks

detraining

Defined as partial or full reductions in training-induced physiological adaptations in response to lower training or inactivity.

● Increase physical demands=further improvements; maintenance-level training = prevent physiological decline; stopping of training=detraining.

● Significant loss(25%) of cardiorespiratory endurance in 10-20daysof inactivity

Cardiorespiratory fitness

the ability to perform prolonged endurance exercise measured in VO2Max.

VO2Max-

Maximum oxygen the body can utilize

Strength

a maximum force generated by the muscle

Power

product of muscle force x velocity.

Neuromuscular system

Training can improve size(hypertrophy) and strength

○ Disuse can result in decreased size (atrophy) and strength

○ Strength gains in later stages of training

○ Increased size of the individual skeletal muscle fibers

Overreaching

excessive training that results in short-term performance decrements yjay can be reversed in several days to several weeks with proper training and rest

Adequate fluids,CHO(glycogen) and CHON(proteins synthesis and healing).

Overtraining

series of symptoms called overtraining syndrome

overtraining syndrome

more serious, long-term derements in performance (several weeks to months) to recover from