Sports and Exercise Nutrition - Exam 2

Creatine

• Effective in short term, high intensity sports for improving lean body mass

• Improves weightlifters performance

• No effect on endurance performance

• No research of claims of dehydration, strain/pulls

• Some users don’t respond

• Pair with 50-100 g CHO

Rapid Creatine Loading

20 g per day

Maintenance Phase Creatine

3-5 g/day

Caffeine Mechanism

Decreases perception of effort, heightened sense of awareness, increases pain threshold

• no evidence of fat burner

Caffeine and Endurance Performance

Greater effect if caffeine naive, usually one hours before exercise

Caffeine Dosage

• Beginning —> 2-3 mg/kg

• 200-400 mg per day considered safe

Caffeine Adverse Effects

Increased BP and HR, GI Distress, Insomnia

• more common in caffeine naive

• <450 mg does not have diuretic effect

Sodium Bicarbonate

• 0.3 g/kg taken 60-90 minutes prior to exercise

• Effective way to buffer acidity during high intensity exercise lasting 1-3 minutes

• Side Effects - GI distress, need to be cautious with dosage

Beta-Alanine

Nonessential amino acid

• buffer of muscle pH, may enhance high intensity exercise

Beet Juice/ Nitrate

Potentially effective for improving endurance exercise capacity

Omega-3

• Exercise induced bronchospasm due to asthma

• NOT EFFECTIVE to reduce inflammation, enhance immune system, improve performance

• Promising Research

Probiotics

Enhance GI and Immune health

• Promising research

Branched Chain Amino Acids - BCAAs

• Isoleucine, leucine, valine

• LIMITED EVIDENCE for reducing post exercise fatigue

• PROMISING RESEARCH for immune system support

• Can be consumed from foods

Content Certified

Tested to ensure that supplements do not contain unsafe levels of contaminants and to verify label claims

• ONLY NSF does this

In which compartment is the largest amount of body fluid stored

intracellular fluid

The primary cation in extracellular fluid is

sodium

having a normal or optimal amount of water in the body, sufficient to support fluid balance and meet required physiological functions would be termed

euhydration

wearing uniforms and protective gear while exercising in the heat typically

restricts the evaporation of sweat and results in body temperature rising

a person exercising in a hot and humid environment might lose how much fluid through sweating

1 to 2 L per hour

water only is an appropriate pre exercise beverage for:

exercising lasting less than 60 minutes

two factors that might be associated with hyponatremia include

large losses of sodium in sweat and excessive water intake

according to the current body of scientific research, what effect does exercise have on an athlete’s vitamin requirements?

increases the need slightly but supplementation not necessary

the intake of which vitamin is likely to be low in both sedentary and athletic populations

vitamin D

which of the following is true regarding athletes and the consumption of an adequate amount of vitamin A from food

vitamin A intake generally reflects fruit and vegetable intake

high bioavailability refers to a compound that

has a high degree of absorption and utilization

which of the following is not a basic function of minerals

providing energy for metabolism

which of the following is not classified as a macromineral

iron

a mineral that is under substantial hormonal control is

calcium

in the absence of a deficiency, as mineral consumption increases, the amount absorbed:

decreases

the age at which peak bone mineral density occurs is

35-60 years

the two factors that best explain the increases risk for osteoporosis in elite female distance runners are

low energy intake and low estrogen

why is iron not well absorbed from the intestinal tract

overabsorption of iron has potentially harmful physiological effects

effect of iron deficiency anemia on performance

decline in aerobic capacity, endurance capacity and oxygen utilization

which of the following is likely true regarding athletes and upper respiratory tract infections

prolonged exercise increases risk for URTIs

what is the potential problem with consuming excess supplemental zinc

interference with iron absorption

what is the potential problem with mineral supplements that have high bioavailability

excess absorption

an adequate dietary intake of which two minerals is usually predictive of an adequate intake of all the essential minerals

calcium and iron

the word diet should be defined as

a pattern of eating

nutrient density is based on the relationship between

energy and nutrients

why does too large of a volume of food prior to exercise result in GI distress

blood flow to GI tract is decreased with the onset of exercise

why is it important to consume high to moderate GI carbohydrates immediately after exercise

stimulates a more rapid insulin response

by what mechanism does caffeine most likely enhance endurance performance

decreases the perception of fatigue

other than training, which of the following is likely to have the greatest impact on improved endurance performance

carbohydrate loading

considering the body of scientific literature to date, what effect do dietary supplements have on performance

only a few have been shown to improve performance

a comprehensive nutrition periodization plan begins with

assessment

estimated average requirements (EAR)

• average daily intake level that meets the needs of 50% of people

• Used for planning and assessing diets for populations

recommended dietary allowances (RDA)

• average nutrient intake level that meets the needs of almost all health individuals in a particular group

• may be modified to prevent disease

  • 98% of population

Adequate intake (AI)

• average nutrient level that appears sufficient to meet the needs of almost all healthy individuals in a grouo

tolerable upper intake levels (UL)

• all sources vs fortified foods vs supplements

• used to assess toxicity

• there is an increased risk of toxicity when intakes exceed a certain value

chronic disease reduction intake (CDRR)

there is an increased risk of chronic disease when intakes exceed this value

acceptable macronutrient distribution range

reference intake that has an upper and lower boundry

poor food choice often lead to low vitamin intake

• vitamin D, E, A, C least consumed vitamins

• magnesium and calcium least consumed minerals

niacin

• release of energy from CHO

• blocks release of free fatty acids

• whole and enriched grains, chicken, tuna, pork

thiamin

• release of energy from CHO, pro, fat

• breads, cereals and grains

• ATP production

riboflavin

• ATP production

• CHO to energy

• supplementation may be beneficial to vegans

• Found in breads, cereals, veggies, milk, meat

vitamin B12

• needs intrinsic factor produced in stomach for absorption in small intestine

• found in meat, fish, poultry, eggs, milk

• RBC production and neurotransmitters

folate and folic acid

• RBC production

• breads, cereals, beans, oranges, leafy green vegetables

iron

• hemoglobin and myoglobin synthesis

  • VO2 and endurance capacity

• needed for oxidative metabolism

• red meats, oysters, spinach

zinc

• immune health

• inhibits copper absorption

• meat, fish seafood

magnesium

• influence bone metabolism, important in metabolic processes like neuromuscular contraction and mitochondrial function, macronutrient synthesis

• nuts, legumes, lentils, beans, peas, dark green vegetables

vitamin C

• fruits and vegetables

• antioxidant, immune health

• counteracts reactive oxygen species

serum ferritin

blood measure of iron

transferrin

not measured as often in practice

hemoglobin

iron contained protein in RBC

• by the time it has dropped below a normal range; can have anemia

stage one iron deficiency

bone marrow stores depleted, decreased serrum ferritin

stage two iron deficiency

• continued ferritin decrease

• less iron in hemoglobin

stage three iron deficiency

very low serum ferritin and decreased hemoglobin

• iron deficiency anemia

factors that increase need for vitamin

• decreased absorption from GI tract

• increased loss in sweat and urine

• increased utilization due to exercise stress

• increased need associated with skeletal muscle mass

factors that could decrease need for vitamins

• decreased excretion in urine

• more effective recycling processes

bone health

calcium, vitamin D, C, A, flouride, phosphorus

energy metabolism

chromium, b-vitamins

immune health

zinc, vitamin D, C, A

blood health

Iron, Vitamin K, B12, B6, folic acid, copper

antioxidants

vitamin A (beta carotene), E, C, Selenium

Vitamin D

• promotes calcium absorption

• regulates phosphorus metabolism

• fortified cows milk, fish oil, salmon, tuna, egg yolk

phosphorus

• meat and dairy

vitamin A

• antioxidant

• milk, animal liver, egg yolks

what type of athletes may benefit from supplements

pregnant athletes, master level, vegan, calorie restricting

radiation

fluids radiating from body into surrounding air

conduction

heat transferred through contact with an object

• cooling down on a cold bleacher after a hot run

convection

movement of air or water over the body

• wind cooling you down after a run

vaporization

evaporation of water

• accounts for more than 80% of loss when hot or day

• dipped sweat is wasted sweat

factors affecting sweat rate

clothing, body size, environment, hydration, gender, temperature, acclimation, dietary

heat acclimation

going to sweat more and blood volume is going to increase

• decreases core temp, HR and sodium loss

gastric emptying

optimizing rate of draining to small intestine so that maximum absorption of fluid happens

• maximized by amount of fluid in stomach

  • more fluid up to 700 mL the better the emptying

• 1L/hr

• After 70% VO2max, decreases

well hydrated

<1% body weight decrease

minimal hydration

1-2% decrease in body weight

significant dehydration

3-5% decrease

urine color

pale yellow is best

hydration goals

• schedule not thirst

  • consume 60% of usual sweat rate

• all fluids hydrate

  • includes caffeine containing beverages

• establish hydration protocol

• make beverages easily accessible

hot and humid environments

risk of dehydration and heat injury increase, heat dissipation affected

colder environments

greater respiratory losses, sweat with layered clothing, decreased intake of fluids

odds ratio of <1

behaviors are less likely to happen

• 100 - x = % less likely to happen

• decreased risk among exposed

• protective exposure effect

odds ratio of 1

no difference between reference and testing group

• incidence rates of disease or outcome in exposed and nonexposed are identical (no association

odds ratio >1

indicates an increased risk among the exposed

• harmful exposure effect

performance enhancing technique

• mechanical aids - lightweight running shoes

• psychological aids

performance enhancing substances

• physiological aids - blood doping

• pharmacological aids - growth hormones

• nutritional aids - protein supplements

purity

related to lack of contamination and accurate labeling

safety

consider ingredients and dose

what adults use dietary supplements?

• 60+, older, exercisers, females, white, higher education, higher SES, lower BMI, moderate alcohol intake, never or former smokers, healthy BMI

• Older adults - bone health, eye health

• Younger adults - enhance immune system