Sports Nutrition Flashcards
What are the components of fitness?
Flexibility, muscle strength
How much physical activity should be done per week? Where does the amount come from?
150 minutes per week (minimum activity to have a positive impact on their cardiovascular system)
What is frequency?
3-5 sessions per week
What is the equation for maximum heart rate?
220-age
What is intensity?
50-90% of maximum heart rate
What is time (duration)?
30 minutes minimum
What are the three types of fitness?
- Resistance
- Endurance
- Flexibility
What is resistance?
moderate intensity strength training
What is endurance?
cardiorespiratory
What is flexibility?
stretching the major muscle groups
What are the 4 types of fuels used?
- ATP-CP (anaeorobic)
- ATP from carbs - lactate (anaerobic)
- ATP from carbs (aerobic)
- ATP from fat (aerobic)
What are the types of skeletal muscle cells?
1) Slow twitch fibers
2) Fast twitch muscle fibres
Define slow twitch fibres.
endurance muscle, lots of mitochondria
Define fast twitch fibres.
less mitochondria, fast response, high intensity, easily fatigued
Compare the twitch fibres of sprinters and marathon runners.
sprinters: fast twitch
marathon: slow twitch
What does phosphocreatine get converted to during exercise? What does it produce?
Converted to creatine
Produces ATP
Why do people take creatine supplements?
increase creatine in muscle to phosphocreatine, high intensity activity for a longer period of time (power lifting), good system to have for lots of energy
What are the nutrients used for energy during exercise?
Carbohydrate and fat
What is main source of energy during mild exercise?
Plasma free fatty acids
What is main source of energy during moderate exercise?
Muscle glycogen
Muscle triglycerides
Plasma fatty acids
What is main source of energy during heavy exercise?
Muscle glycogen ++
Muscle TG, FFA, plasma glucose are equal
Describe anaerobic processes to
yields energy quickly, not a lot though
During anaerobic metabolism, the energy provided by?
▫ Circulating glucose
▫ Muscle glycogen
How long does anaerobic metabolism support muscle contraction?
1-3 minutes
How does the rapid anaerobic metabolism occur?
Through glycolysis
When does anaerobic metabolism stop?
When lactate builds up, takes longer to be converted back to glucose in the liver
During aerobic metabolism, the energy provided by?
▫ Circulating glucose
▫ Muscle and liver glycogen ▫ Adipose tissue triglycerides
Which metabolism is faster? Which produces more ATP?
- Anaerobic
- Aerobic
How does the aerobic metabolism occur?
oxidative phosphorylation
Complete burning of oxygen to CO2 and H2O
How long does aerobic metabolism support muscle contraction?
Supports muscle contraction for >3 minutes ▫ e.g. 1500-meter run, marathon, etc.
Compare high carb, normal mixed and fat/protein diet in terms of endurance time.
High carb: 167 min
Normal mixed diet: 114 min
Fat and protein diet: 57 min
What is VO2 max?
- Measure of the max amount of oxygen that an athlete can use
- The higher, the more fit you are and the more aerobic capacity you have
What are factors that influence VO2 max?
Genetics, age, differences in response to training
After 20 minutes of exercise, what happens?
Use less glucose, more fat
What does hitting the wall mean?
- Glycogen depleted after 2 hours of vigorous activity (75% of VO2 max)
- Hypoglycemia + depleted glycogen stores = half nervous system function
How do you avoid hitting the wall (glucose exhaustion)?
1) Eat a high CHO diet,
2) Ingest glucose during the activity,
3) Eat CHO rich foods after the activity, and
4) Train your muscles to store as much glycogen as possible.
Define carbohydrate loading.
eating more than normal amounts of carbohydrate, while tapering (less training) the training or resting 2-3 days before the event.
How does glycogen concentration compare in trained and untrained people?
Glycogen stored in muscle is higher in trained people
Why do athletes use carbohydrate loading?
Athletes use this method to load their muscles with energy (glycogen) to improve performance in high intensity- endurance exercise bouts.
Who benefits from carbohydrate loading?
Benefits athletes who need to perform for >90minutes
What is Garbo-load?
Carbo-load is NOT garbo-load. The type of food chosen when loading with will have an impact on performance.
How do you carbo load?
Starting 3 days before event, cut back on workouts (tapering) and increase complex CHO to 70% of energy intake
What should you have during the high intensity endurance activity?
• Take glucose drinks during endurance activity
What do you need to train for high intensity endurance activity performance?
Train muscles to maximize glycogen stores and to adapt to use less glucose and more fat
What is the pre-event diet composed of?
- High CHO
- Moderate protein
- Low Fat
- Fluids
How much water should be drunk during the event?
1 cup of water for every 15 minutes
What should be done post-event?
• Rehydrate • Refuel
• Relax
• Eat CHO-rich foods within 15-30 mins of activity
(MAX 2 hours )
Why is there no blood sugar spike when consuming high sugar diet during exercise?
muscles have non-insulin dependant glucose uptake, using a lot more glucose from blood so no spike in blood sugar
How much carbs do athletes report eating?
8 grams per kg
55% (within AMDR)
What are the recommendations for athletes in terms of carb targets?
- Low intensity (3-5g/kg)
- Moderate - 1h (5-7g/kg)
- Endurance - 1-3h (6-10g/kg)
- Extreme - 4-5h (8-12g/kg)
What are the total CHO needs for endurance athletes?
8-12 g/kg/d 2-3 days before the event + exercise taper
What type of CHO should athletes eat during carbo loading?
- Focus on HI GI, compact sources of CHO
- Jams, juices, fruits, refined grains (white bread, pasta, rice) • Dairy: Flavoured yogurts/milks
- Vegetables: peas, tomato sauce, corn..
What are CHO rich foods to avoid during carbo loading?
- HI fiber (low GI) foods
- Bran cereals/breads
- Legumes (lentils/beans)
- Cruciferous vegetables (broccolis, cauliflower)
What are potential side effects of high fibre foods?
- Feeling heavy and bloated especially if having large meals in one sitting + high fiber foods
- Expect 2-4 lbs wt gain
How does fluid intake recommendation vary?
- Needs vary between sports
- drink more if you sweat heavily
- drink more if you are training in hot/humid conditions
What is the recommendation for food intake?
≥ 60-90 minutes : WATER + 30-70 g CHO/hour
What is the purpose of post workout nutrition?
↓ recovery time between sessions and improve the quality of training during subsequent sessions
Where is CHO taken to after exercise?
Rapidly stored in the muscle as glycogen
How does protein help post-workout?
the muscle recover from, and adapt to training
What is the carbohydrate to protein ratio that is best for muscle recovery? What are these recommendations best for?
- 2:1 to 4:1
- vigorous intensity
longer duration (at least 60-90 min) activities
How much carbohydrate (in g) to protein (in g) should be eaten post-exercise?
- ~1 – 1.2 g/kg carbohydrate
* ~ 0.3 - 0.4 g/kg protein
When should you eat after exercise? What is this called?
- Immediately
- 15-30 minutes after exercise : muscles most receptive to refueling
- Glycogen Recovery Window
What happens if you do not refuel over 2 hours after exercise?
rate of muscle protein synthesis and
energy storage is decreased by 50%
What is the RDA for protein for power athletes?
1.2-1.7g/kg/d
What is the RDA for protein for endurance athletes?
1.2-1.4g/kg/d
What is the RDA for protein for endurance athletes?
1.2-1.4g/kg/d
Name 4 nutritional related health problems in female athletes.
- Eating disorders or disordered eating (not a normal eating plan, not as severe)
- Body composition changes (ex: Amenorrhea)
- Bone loss
- Anemia
Is there any added beneficial effect if you eat more than 2 grams/kg/d of protein? What happens if you have too much protein?
NOPE, more than 4 grams per day = effects on kidney (needs to drain all the nitrogen), need to drink much more water
What do you need to emphasize in female athletes?
- Emphasize adequate E, protein, Fe and Ca
* Emphasize strength, stamina, and successful performance
What do you need to de-emphasize in female athletes?
De-emphasize body weight, dieting, and performance misconceptions
How does iron impair physical performance?
↓ Hemoglobin to carry oxygen
What is sports anemia?
- Not iron-deficiency anemia
- Loss of old blood cells
- “Diluting” the red blood cells
- To become more efficient at exercise
- Temporary thing, blood cells will eventually catch up
- Blood volume increases before your blood cells increase
What are the consequences of sports anemia?
- Expansion of blood volume
- Unaltered oxygen carrying capacity
What is the female athlete triad?
- Low Energy Availability/Disordered Eating
- Bone loss/Osteoporosis
- Menstrual disturbances/Amenorrhea
Define ergogenic aids.
substances or
techniques used in an attempt to enhance physical performance
Give examples of substances promoted as ergogenic aids.
Amino acids, plant sterols, sugars
Most aren’t effective
How can sodium bicarbonate be used as an ergogenic aid? What is the side effect?
- Reduces lactic acid and delays fatigue; enhances power and strength
- Explosive diarrhea
What does the International Society of Sports Nutrition say in terms of supplementations (creatine) for POWER athletes?
Proper supplementation can improve maximal power/strength and work performed by 5-15%
What are some advantages of exercising for weight loss?
• Eat more • Maintain lean body mass and muscle mass • Increase fat loss • Increase aerobic fitness
How does fitness affect the elderly?
- Increases muscle mass, strength, function, mobility, activity • Slows decrease in bone density
- Increases immune response
- With social interaction – improves SLEEP
How will fitness affect body composition changes?
↑ LBM and ↓ fat mass
What three chronic diseases does exercise influence?
- Type II diabetes
- CVD
- Osteoporosis
How does exercise improve type II diabetes?
- Improves glucose tolerance
* ↓ blood pressure
How does exercise improve CVD?
- ↓ serum lipids and cholesterol
* ↓ blood pressure
