13.3 Fuel Use during physical activity Flashcards
What is the difference between aerobic and anaerobic activities?
Aerobic (With oxygen): moderate/steady exercise. Body can match the fuel needs with fuel delivery
Anaerobic (Without oxygen): High intensity/beginning of exercise. Body needs to figure out how to deliver oxygen.
What is the main type of fuel in anaerobic activities?
Glucose: C6H12O6 -> pyruvate -> lactate + ATP
Also a little bit of ATP that was pre-formed and CP-ATP (but only for a few seconds)
What is the main type of fuel in aerobic activities?
Glucose: C6H12O6 + 6 O2 -> water, CO2, and ATP
Can also use fats and amino acids
In aerobic activities, which types of nutrients does the body prefer to use?
Sugars and fats, not proteins (only 5-10%)
Why can we not sustain anaerobic activities?
The lactate acid that builds up is painful to our muscles
How do we measure fuel use against the duration of exercise?
First 2 minutes of PA are anaerobic (ATP (0-2 seconds), ATP-CP (3-10 seconds), and anaerobic glycolysis)
At moderate intensity after 2 minutes, aerobic metabolism is dominant (Aerobic glycolysis (2-20 mins), Aerobic fatty acid metabolism (21+ mins))
What is Creatine-Phosphate ATP?
A form of ATP made when creatine phosphate donates its phosphate group (Phosphate is part of ATP)
Where does the glucose for aerobic fuel come form?
Muscle glycogen and blood glucose
After 20 minutes of exercise, what is the main fuel source for aerobic activities?
Lipid metabolism. Comes from muscle triglycerides and adipose tissue lipid stores
As we exercise longer, energy comes more from ____ rather than glucose
lipids
How does exercise intensity determine what type of fuel we use?
Low-moderate PA = aerobic zone. Uses all fuels, but prefers lipids
High intensity activities = anaerobic zone. Can only use glucose, ATP, and ATP-CP. Some aerobic metabolism will still take place (with lipids)
