1. Energy and Exercise
AP BIO

2. Energy in Humans What sort of activities cause you to use more energy?
Lets look at running

3. Human Body The human body has a limited amount of ATP stored in it
The reserve can last about 90 seconds of intense exercise (like sprinting)
What does this mean?

4. Intense Exercise Your body has 3 sources of ATP
Stored ATP
ATP’s from fermentation
ATP’s from cellular respiration
The stored ATP will only last about seconds
After that we begin to undergo lactic acid fermentation

5. Lactic Acid Fermentation
We can use the ATP’s in lactic acid fermentation for about 90 seconds
What builds up in our muscles when this happens?
Lactic Acid
The only way to break down and get rid of lactic acid is by using oxygen

6. Post Sprint Why do runners breath heavily after a race?
Runners breathe heavily after a race to get oxygen to our muscles to break down lactic acid

7. Running a Mile
We have just said that we can only generate ATP with lactic acid fermentation for about 90 seconds.
What if you were running a mile?

8. Long Term Energy
Lactic Acid releases energy very quickly (but can only last a short time)
When running a mile or more, your body will switch over to cellular respiration (instead of fermentation)
Cellular respiration releases energy much more slowly
This is why athletes must pace themselves during a race

9. Energy Sources
The body stores energy in a carbohydrate known as glycogen
After minutes of physical activity, the body will use other sources for energy
Fats
Proteins