Sport Nutrition Flashcards
- What is a Calorie (kcal)?
–> Amount of energy needed to
__________________________
heat 1 liter (kg) of water by 1oC
Muscle tissue is ~_________
75% water
Athlete begins to _____________:
◼ Baroreceptors detects ↓ BP
◼ Sent to hypotahlamus
◼ Signals the pituitary gland to increase production of ADH
◼ Elevated ADH signals the kidneys NOT to remove additional water from the blood
◼ Blood pressure does not drop any further (for a while!!)
Dehydrate
Carbohydrates
Glycogen types:
- ______ Glycogen
–> Glucose is constantly being released at rest & while sleeping
–> Glycogen phosphorylase o “Dripping faucet”
–>Why? To fuel the brain
Liver
Carbohydrates
Glycogen types:
- ________ Glycogen
—> Mostly accessed during muscle contractions (physical activity) for energy
Muscle glycogen
Protein
Energy substrate when other energy substrates are running low
Gluconeogenesis via ____________
Can result in muscle loss
Nitrogen & ammonia (NH3) accumulation
Deamination
__________________________:
leucine, isoleucine, valine
The 3 amino acids that can be converted
into Acetyl CoA within the muscle
Branched Chain Amino Acids (BCAA”S)
Question: How many calories should I be consuming?
- ________ daily intake
Women: _______ k/cal
Men: _______ k/cal
Average
WOMEN : 2000
MEN: 3000
Common Question: How much protein should I be eating?
Range between ________ - ________ grams of protein/kg/day
Examples within this range include:
Strength AND endurance athletes
0.8 – 3.0
How much carbohydrate should I be consuming? (continued)
Low levels of muscle glycogen results in important factors in training “staleness” and ‘plateau’
Bad for training and game day
Two main causes of low
muscle glycogen
Overtraining
Inadequate ____________ intake
complex carb
What is “Carb Loading”?
Method of enhancing muscle glycogen levels prior to an endurance event
approaching _____ minutes (including warm-up)
90
Common Question: Should I be concerned with minerals being lost in sweat?
You should be more concerned with ________ loss, than _________ loss
Water, than mineral
Sport drinks do supply __________ & _________
energy & electrolytes
Common Question: What should I eat before my game/race?
2 Goals: Provide energy and ensure hydration
healthy carbohydrates, 1-2 hours before is optimal
Why healthy carbs?
Common Question: What should I eat before my game/race?
2 Goals: Provide energy and ensure hydration
healthy carbohydrates, 1-2 hours before is optimal
Why healthy carbs?
_________________
Not a large meal or one high in fat
slows gastric emptying
Reduced _____________ muscles
Why and what effect on performance?
Rebound Hypoglycemia
Reduced blood flow to
Common Question: What should I eat after exercise?
Mod-High glycemic foods preferred to avoid ________________
Replenish glycogen quick, if not, protein will be broken apart to produce glucose for your brain
gluconeogenesis
Why do Gatorade© manufacturers add sodium AND potassium to Gatorade© instead of just twice as much of one of either potassium or sodium? (be sure to link to water regulation)
Gatorade® includes both sodium and potassium in its formulation because both electrolytes are essential for water regulation, electrolyte balance, and hydration status in the body. By providing a balanced combination of sodium and potassium, Gatorade® helps to replenish electrolytes lost during exercise, support fluid balance, and enhance hydration and performance for athletes and active individuals.
Electrolyte Balance and Hydration:
Both sodium and potassium are necessary for maintaining electrolyte balance, proper cellular function, and hydration status in the body. Imbalances in sodium and potassium levels can lead to dehydration, electrolyte disturbances, and impaired physiological function.
Sports drinks like Gatorade® are formulated to replenish electrolytes lost through sweat during exercise and support hydration, endurance, and performance. By providing both sodium and potassium, Gatorade® helps to replace electrolytes, maintain fluid balance, and support optimal hydration during physical activity.
A person burned 360 k/cal after 90 minutes on a treadmill, how many grams of fat was burned? (also, briefly explain why this question is only theoretical).
360/9 = 40g
Theoretical b/c don’t only use fat as energy source… ue glycogen and protein… etc. Equation doesn’t take into account other forms oof energy
Why are “B” vitamins vital for energy, even though they contain no energy themselves?
B vitamins themselves do not provide energy, they are vital for energy metabolism by serving as coenzymes and facilitating key biochemical reactions involved in the conversion of macronutrients into ATP. Without adequate B vitamin intake, the body’s ability to generate energy from food sources is compromised, leading to decreased energy production and potential adverse effects on overall health and vitality.
Explain why a meal high in fat OR simple carbs is NOT recommended before exercise?
In summary, meals high in fat or simple carbohydrates are not recommended before exercise due to their potential negative effects on digestion, energy availability, and performance. Instead, athletes should focus on consuming balanced meals rich in complex carbohydrates, lean protein, and healthy fats to support sustained energy, optimize glycogen stores, and minimize gastrointestinal discomfort during physical activity. Timing meals to allow for adequate digestion before exercise and choosing nutrient-dense foods that provide a steady source of energy can help enhance performance and support overall health and well-being.
Explain the optimal method of “carbohydrate loading”?
Carb loading is a method of enhancing muscle glycogen levels prior to an endurance event to help give “fuel”.
Optimal:
- approaching 90 mins before(including warm up)
- maintaining high complex carb intake WHILE also tapering off severity of physical activity days before
What is better for hydration during exercise, water or Gatorade? Use specific examples to support your answer.
SHORT distance/exertion = just water
LONGER/extensive exercise = gatorade
End of the game energy drinks help keep stamina and hydration levels up
(ex. at bench hockey games)
Sport drinks provide energy, give electrolytes(Na and K)
Long Answers
1. An athlete may dehydrate during an endurance event causing blood pressure to drop. Explain why blood pressure drops and what the body can do to raise blood pressure once it drops below homeostatic levels (be sure to include multiple hormones in your answer).
When an athlete becomes dehydrated during an endurance event, blood pressure may drop due to several physiological mechanisms. Dehydration reduces blood volume, which in turn decreases cardiac output—the amount of blood pumped by the heart per minute. As a result, less blood is available to circulate throughout the body, leading to a decrease in blood pressure. Additionally, dehydration can cause electrolyte imbalances, such as low sodium levels, which can impair the body’s ability to regulate blood pressure and fluid balance.
Once blood pressure drops below homeostatic levels, the body initiates several compensatory mechanisms to raise blood pressure and restore circulation. These mechanisms involve the activation of hormonal and neural pathways to increase vascular tone, cardiac output, and fluid retention. Here’s how the body can raise blood pressure in response to dehydration:
Activation of the Renin-Angiotensin-Aldosterone System (RAAS):
Dehydration triggers the release of renin from the kidneys into the bloodstream. Renin acts on angiotensinogen (produced by the liver) to convert it into angiotensin I, which is then converted to angiotensin II by the angiotensin-converting enzyme (ACE) in the lungs.
Angiotensin II is a potent vasoconstrictor that constricts blood vessels, increasing peripheral vascular resistance and raising blood pressure.
Angiotensin II also stimulates the secretion of aldosterone from the adrenal glands. Aldosterone acts on the kidneys to increase the reabsorption of sodium and water, leading to expansion of blood volume and restoration of blood pressure.
Sympathetic Nervous System Activation:
Dehydration activates the sympathetic nervous system, leading to the release of catecholamines (epinephrine and norepinephrine) from the adrenal glands and sympathetic nerve terminals.
Catecholamines stimulate the heart to increase heart rate (positive chronotropic effect) and contractility (positive inotropic effect), resulting in an increase in cardiac output.
Catecholamines also cause vasoconstriction of peripheral blood vessels, redistributing blood flow to vital organs and tissues and raising blood pressure.
Antidiuretic Hormone (ADH) Release:
Dehydration stimulates the release of antidiuretic hormone (ADH), also known as vasopressin, from the posterior pituitary gland.
ADH acts on the kidneys to increase water reabsorption, reducing urine output and conserving body fluids.
By increasing water retention, ADH helps to expand blood volume and raise blood pressure.
In summary, when an athlete becomes dehydrated during an endurance event, blood pressure may drop due to reduced blood volume and electrolyte imbalances. To counteract this drop in blood pressure and restore circulation, the body activates compensatory mechanisms, including the renin-angiotensin-aldosterone system (RAAS), sympathetic nervous system, and release of antidiuretic hormone (ADH). These mechanisms work together to increase vascular tone, cardiac output, and fluid retention, thereby raising blood pressure and maintaining perfusion to vital organs and tissues during exercise.
