Sports Nutrition Flashcards
ATP-CP energy system
Quick source of ATP
The ATP–creatine phosphate system transfers a high-energy phosphate from creatine phosphate to adenosine diphosphate (ADP) to regenerate ATP.
This anaerobic system can provide ATP for approximately 30 seconds for activities such as sprinting and weightlifting.
Lactic acid energy system
Breakdown of glucose (glycogen) to lactic acid (lactate)
Doesn’t require oxygen (anaerobic)
Rise in acidity triggers muscle fatigue
Oxygen energy system
Breakdown of carbohydrate and fat for energy
Requires oxygen
Produces ATP more slowly
Teamwork in energy production
Anaerobic systems
Aerobic systems
Glycogen depletion
Steady drop for first 1.5 hours
Entirely depleted ~ 3 hours
Endurance training
Decreases reliance on anaerobic systems
Extends availability of glycogen
E.g of activities:
Brisk walking or jogging, Yard work (mowing, raking), Dancing, Swimming, Biking, Climbing stairs or hills, Playing tennis or basketball.
Muscles and muscle fibers
Slow-twitch fibers
Fast-twitch fibers
Relative proportion determined by genetics
Slow twitch VS Fast twitch muscle fibers
The two types of skeletal muscle fibers are slow-
twitch (type I) and fast-twitch (type II).
Slow-twitch muscle fibers support long distance
endurance activities like marathon running.
While fast-twitch muscle fibers support quick,
powerful movements such as sprinting or weightlifting.
Optimal Nutrition for Athletic Performance
Consume adequate energy and nutrients
Maintain appropriate body composition
Promote optimal recovery from training
Maintain hydration status
Energy Intake and Exercise
Fuel for training
Maintain healthy weight
Support growth (if adolescent)
May require frequent meals and snacks
High-carbohydrate diets
Increase glycogen stores
Extend endurance
Carbohydrate loading (CL
60–70% of calories from carbohydrate
CL done the week before a high-endurance activity.
One to three days before the event, increase your carbohydrate intake to about 8 to 12 grams of
carbohydrate per kilogram of body weight.
Cut back on foods higher in fat to compensate for the extra carbohydrate-rich foods.
Decrease exercise intensity prior to competition
Carbohydrate and Exercise
During exercise
Sports drinks (4–8% carbohydrate)
After exercise
Replenish glycogen stores
1 to 1.5 grams carbohydrate per kg both 30 minutes and 2 hours after exercise
Fat
Major fuel source for endurance activities
High-fat diet not needed
Recommendations
i) Moderate fat intake: 20–35% of calories
ii) Limit saturated fat to less than 10% of energy
iii) Avoid trans fat as much as possible
Protein and Exercise
1) Protein recommendations
Adults: 0.8 grams per kg body weight
Endurance athletes: 1.2–1.4 g/kg
Resistance-trained athletes: 1.6–1.7 g/kg
2) Protein sources
Foods: lean meats, fish, low-fat dairy, and egg whites
3) Protein intake after exercise
Helps replenish glycogen
Dangers of high-protein intake (dehydration, urination frequency)
