Sport Nutr Exam 4

Top supplements used

Multivit, Vit C, Protein products

Food items used to supplement

sports/energy dinks, sports bars

reason of supplementation

maintain health, growth, repair, immune, weight management, improve sleep and exercise performance

Supplement regulation

FDA, FTC, WADA, NCAA, MLA

Supplement safety

Informed sport, NSF

Informed sport

every single batch is tested

Informed choice

Monthly batches ae blinded tested

Muscle building suppl. recall

seteroids

Weight loss suppl. recall

prescription appetite suppressant, stimulants and laxatives

Sexual enhancement suppl. recall

active ingredients in several commonly prescribed meds.

Health concerns of suppl.

Cardio, renal, hepatic issues, seizures, exceeding ul

what is WADA prohibited list doing

adding more all the time, banded substances

WADA prohibited list

stimulants, narcotics, cannabinoids, glucocorticoids, beta blockers

NCAA permissible

“allowed” Vit and minerals, energy bars, carb/electrolyte drinks

NCAA impermissible

“not allowed” amino acids, melatonin, creatine

Supplement efficacy

how well a supplement actually works for what it claims (based on real scientific evidence, not marketing)

Hierarchy of scientific evidence

Ideas/expert opinion, case report, cross sectional studies, case control , cohort, controlled trail, meta analyses systematic review

Suppl. with strong evidence of efficacy

caffeine, creatine monohydrate, nitrate, sodium bicarbonate, beta-alanine, glycerol

Risk benefit analysis

• is it safe

• is it legal

• is it effective

• can i afford it

Reactive oxygen species (ROS)

oxygen-containing reactive molecules (some are radicals) produced during normal metabolism and increase with exercise

Radicals

molecules with an unpaired electron, making them highly reactive and able to damage cells

Reactive Nitrogen species (RNS)

nitrogen-based reactive molecules similar to ROS that can also affect cells during stress/exercise

Anitoxidant

substances that neutralize radicals and protect cells from damage (body makes some; others come from diet)

Superoxide (O2-)

a primary ROS formed during exercise; can start chain reactions of cell damage if not controlled

Superoxide dismutase

enzyme that converts superoxide into less harmful molecules (first line of defense)

Hydroxyl radical (-oh)

extremely reactive and damaging ROS; can harm proteins

Nitric oxide (NO)

a reactive nitrogen molecule that helps with blood flow and muscle function, but in excess can contribute to stress

Glutathione peroxidase

enzyme that reduces harmful peroxides using glutathione to protect cells

Catalase (Cat)

enzyme that breaks down hydrogen peroxide into water and oxygen, preventing damage

ROS pathway step 1

depolarization of the muscle from the motor neuron

ROS pathway step 2

Stretching of the muscle cell along the T tubule

ROS pathway step 3

Shear stress as the muscle in the blood vessels move

ROS pathway step 4

Cross bridge formation

ROS pathway step 5

By NOX2, signaling some positive responses to exercise

ROS pathway step 6

NAD+ regeneration

What happen to ROS with exercise

ROS builds up → hurts performance

How doe oxidants affect k+ regulation

Increase na+/k+ pump → K+ outside cell → muscle fatigue

How do oxidants impact blood flow

decrease NO → decrease blood flow → less oxygen to muscles

What does oxidative stress do to endurance

decreases endurance and muscle perfusion

how do oxidants affect metabolism

decrease fat oxidation/glucose, increase lactate → quicker fatigue

What are the pros and cons of ROS in the body in general?

Pros: cell signaling + immune defense

Cons: oxidative stress → cell damage

What are the pros and cons of ROS in the body of an athlete?

Pros: helps with training adaptations

Cons: too much → fatigue + poor recovery

Should we be intentionally increasing ROS in athletes?

No excess harms performance

Intentionally

Should we be intentionally decrease ROS in athletes?

not too much can block adaptations

Best approach for ROS?

maintain balance

Main role of antioxidants

prevent damage caused by ROS- protect cells from damage

How do antioxidants stop ROS formation

block rxn that create ROS

What does “scavenging” mean ?

Neutralize ROS → less reactive molecules

How do antioxidants use metals?

bind to metals (iron/copper) to stop radical formation

What is lipid peroxidation prevention?

protect cell membranes from damage

Redox balance

ROS,NOx,ect = SOD catalase → oxidative stress, homeostatic range, reductive stress

Nutr antioxidants- vit

Vit ACE beta carotene

Nutr antioxidants- minerals

selenium, copper, manganese

Health risk of antioxidants overuse. general?

• inhibits apoptosis → damaged cells not removed

• excess vitamins → neg side effects

How do antioxidants affect training adaptations?

impair exercise - induced adaptations

why can antioxidants hurt muscle recovery?

Muscle recovery from exercise damage is mediated in part by oxidant signaling

Antioxidants can blunt (reduce or weaken):

• signaling events

• repair mechanisms

Training responses to exercise can be depressed:

decrease in mitochondrial biogenesis

one does of antioxi suppl can:

decrease exercise induced vasodilation, inhinit post exercise increases in HSPs

What are polyphenols

natural, antioxidant-rich micronutrients found in plants that defend against cell damage and reduce inflammation

Name food with polyphenols

colorful fruits (berries, grapes), dark chocolate, coffee, tea, nuts, and vegetables

When should polyphenols be taken?

about 1 hour prior to exercise (300 mg)

How lon should polyphenols be loaded before an event?

about 3 days prior

What performance benefits may polyphenols provide

improved muscle strength recovery and performance

Sports supplement

A product taken to support health, nutrition, or performance

Ergogenic acid

Anything used to directly enhance athletic performance

ASI- suppl. framework A

Evidence level- strong: used to id athletes using best practice protocols

ASI- suppl. framework B

Evidence leve- emerging: use within research or clinical situations

ASI- suppl. framework C

Evidence level- not supportive or none: not suggested may have case with group approval

ASI- suppl. framework D

evidence level- banned of high contamination risk: not used for athletes

Waht is the main goal when evaluating suppl in sports

to assess evidence, saftey, and effectiveness

What is creatine mainly used for

increase atp fpr high intensity performance

what activities benefit most form creatine

short high intensity efforts (<30 sec)

does creatine help endurance performance

mostly no improvement

what strength benefits does creatine provide

increase reps, increase strength, increase lean body mass

what does caffeine primarily affect

central nervous system (alertness and preformance)

what performance effect does caffeine have

increase power output, increase time trail performance

What is carnitine and what is its role in exercise

helps transports FA into mito, for energy production (b-oxidation), but it has limited evidence as an effective ergogenic aid for performance

what is carnosine main role

buffer H+ to reduce muscle acidity

what does b-alanine do

increase muscle carnosine levels

what is sodium bicarbonate used for

buffers acid to delay fatigue

What is a common nitrate source

beetroot juice

what is the nitrate→ nitric oxide pathway

nitrarte (NO3-) from foods → reduced by oral bacteria to nitrite (NO2-) → further reduced in the stomach/blood to nitric oxide (NO)

what are the benifits for nitric oxide

vasidiliation, increase blood flow, increase efficiency, decrease fatigue

Effective dose of nitric

500mg (7mg/kg)

what is HMB used for

muscle recovery and reducing breakdown

what nutr are needed for collagen synthesis

vit c + amino acids (P,K)

when should collagen be taken

15-20 g, 30-60 min before exercise + vit c

what is collagen mainly recommended for

injury recovery (not strong for prevention)

what is glycerol used for

hydration and fulid retention

what does cherry juice contain

melatonin and polyphenols

what sleep benefits may tart cherry juice provide

increase sleep duration and light increase efficiency

what should you consider when combining supplements

effectiveness, interaction, additive benefits

why is context important in suppl.

effect depends on sport, athlete, and situation

What are antioxidants?

Compounds that neutralize reactive oxygen species (ROS) to prevent cellular damage

What are polyphenols?

Plant-based compounds with antioxidant and anti-inflammatory properties

What are key antioxidant mechanisms?

Scavenge ROS, prevent ROS formation, bind metals, reduce oxidative damage

What are common antioxidant/polyphenol food sources?

Fruits (berries, cherries), vegetables, tea, coffee, cocoa, pomegranate

What role do ROS play during exercise?

Help signaling and adaptation, but excess causes fatigue and damage

Why can too many antioxidants be harmful for athletes?

They can blunt training adaptations and recovery signaling