Sports Nutrition Flashcards
What is essential during high-intensity and/or long-duration training?
Energy!
Calculating energy needs depends on…
- Types of exercises.
- Duration and frequency.
- Intensity of exercise.
- Sex of athlete.
- Prior nutritional status/conditioning.
- Age, Body size, free-fat mass.
Formula for calculating energy needs?
*Mifflin St. Jeor equation:
Men: BMR = 10(wt/kg) + 6.25(ht/cm) - 5(age) +5.
Women: BMR = 10(wt/kg) + 6.25(ht/cm) - 5(age) -161.
Then…Multiply by the pt’s physical activity level.
- 2: sedentary lifestyle.
- 3: lightly active (1-3 days/wk).
- 5: moderately active (3-5 days/wk).
- 7: very active (6-7 days/wk).
- 9: ultra active (very hard exercise/sports).
What are the 3 energy systems utilized in exercise?
- Phosphagen
- Anaerobic
- Aerobic
What is happening when your muscles feel the burn?
The anaerobic energy system is exhausted.
Identify all the components - metabolism, max rate of ATP production, capacity to make ATP, lag time to increase ATP production - of the Phosphagen system?
- Metabolism: LOW; ONE STEP.
- Max rate of ATP production: VERY FAST.
- Capacity to make ATP: VERY LIMITED, 10s.
- Lag time to increase ATP production: NONE, INSTANTANEOUS.
Identify all the components - metabolism, max rate of ATP production, capacity to make ATP, lag time to increase ATP production - of the Anaerobic system?
- Metabolism: MODERATE; 12 STEP.
- Max rate of ATP production: FAST.
- Capacity to make ATP: LIMITED.
- Lag time to increase ATP production: SECONDS.
Identify all the components - metabolism, max rate of ATP production, capacity to make ATP, lag time to increase ATP production - of the Aerobic system?
- Metabolism: VERY HIGH, MANY PROCESSES.
- Max rate of ATP production: VERY LOW.
- Capacity to make ATP: UNLIMITED.
- Lag time to increase ATP production: MINUTES.
Macronutrient average recommended need and why does it vary?
It varies depending on training intensity and they type of exercise.
CARBS: 50-60% total caloric intake; 6-10 g/kg BW.
PROTEINS: 10-35% total caloric intake; 1.2-2.0 g/kg BW.
FATS: 20-35% of total caloric intake.
What is the most important source of energy in the body and why?
CARBOHYDRATES (CHO)
- CHO must be present to metabolize fat.
- Primary energy source for the nervous system.
- The only nutrient source for anaerobic activity.
- *Helps maintain muscle tissue, helps w/protein digestion.
Performance is __% physical and __% mental?
90% physical and 10% mental.
What is not recommended for high-performance athletes?
Low-carb diets.
What is important to increase if needs increase due to training volume?
CHO up to 70-75% of caloric intake; 5-10 g/kg of CHO allows for variation in exercise intensity.
Which type of complex carbs is the most important?
COMPLEX
-beans/peas, whole grains, vegetables/fruit, milk or milk alternatives.
What is the main source of energy at rest and moderate activity? Intense activity?
Fat at rest and moderate activity, CHO with intense activity.
What is the crossover effect?
As exercise intensity increases, the body prefers to use carbs for energy.
The crossover point is the intensity, typically a % of VO2max (-65%), where fat and carbs intersect w/the energy from fat decreasing and the energy from carbs increasing; some people do not reach this point during exercise.
What is Glycogen and the storage capacity?
Glycogen is the storage form of glucose.
*about 400g of glycogen stored in muscle and 100g in the liver.
What is important about glycogen storage in the muscles? Liver?
Muscles - can increase glycogen storage capacity w/conditioning (up to 600g). Muscles don’t share it’s glucose.
Liver is the last reserve when you “hit the wall.” DM1 have limited capacity in the liver.
Why is important to replace/maintain glucose in the blood during exercise?
So they glycogen in the liver doesn’t need to be used.
How much carb supplement is needed for replacement for 1 hour of exercise?
None.
How much carb replacement is needed for exercise exceeding 1 hr?
CHO should be replaced at a rate of 30-60g/hr of exercise.
CHO consumption during exercise is determined by what 2 factors?
- Rate of CHO utilization/oxidation rate (est. at 1-1.1 gm of glucose/minute).
- Rate of gastric emptying and intestinal absorption of CHOs.
But remember….not all glucose is the same!
What is the preferred or ideal CHO supplementation during exercise?
Ideally, 6-8% CHO or 14-20g per 8 oz.
Preferred - glucose, sucrose, glucose polymers/maltodextrin and starches metabolized at high rate (gatorade, hard candy, powerbar, etc).
Why are fats important?
- Plays a role in satiety – why in low fat diets, we are hungry.
- Essential element of cell membranes.
- Facilitates absorption of fat-soluble vitamins (K,A,D,E).
What is protein’s role and function?
- Has a role in almost ALL major body functions.
- Provides structure to muscle and other tissue.
- Regulates cell function.
- Maintains fluid and acid-base balance.
- Helps transfer substances throughout the body.
- Energy source.
Which of the amino acids does the body make?
Non-essential; essential comes from our food.
What is the recommended protein consumption before, during and after training?
Before:
- Ideally, 3 hrs before depending on individual to allow AAs to enter blood stream.
- Increase of muscle synthesis and decrease muscle catabolism.
During:
- BCAA supply energy to active muscle when CHOs are low.
- Endurance athletes.
After:
- Increases intracellular availability for muscle synthesis.
- Whole proteins vs hydrolyzed (broken down) proteins vs free amino acids.
What is the recover benefit of combining PRO+CHO?
- Enhanced recovery and protein synthesis.
- Beverages elicit greater insulin release, which increased insulin assists w/better absorption rates.
- CHOs increased uptake.
- Enhanced glycogen restorage.
- Recommended 6-20g PRO w/a 1:4/1:3 ratio w/CHO.