00:01
A sprinter would experience muscle fatigue sooner than the marathon runner because of anaerobic metabolism in the sprinter's muscles, anaerobic metabolism in the marathoner's muscles, aerobic metabolism in the sprinter's muscles, or glycolysis in the marathon runner's muscles.
00:19
So what causes muscle fatigue? so fatigue is caused when the muscle cells just can't contract any, they just don't have the energy.
00:28
So it's a lack of atp.
00:37
So how do cells usually get atp? well, there's the respiration pathway.
00:43
So they have glycolysis as the starting point.
00:47
And then there are two options.
00:50
The first one is the krebs cycle, or citric acid cycle, and the electron transport chain.
00:59
And these are the pathways of aerobic respiration.
01:03
So this is in the presence, of oxygen.
01:08
If there is no oxygen, instead, there's fermentation.
01:15
And in animals like us, that's lactic acid, fermentation.
01:23
So this is in the anaerobic conditions.
01:30
So first, glycolysis.
01:33
Lycolysis is happening in both of them.
01:35
It's not responsible fatigue.
01:38
Lycolysis is the first step of either pathway.
01:41
And if oxygen is unavailable, glycolysis is the only.
01:44
Way to get atp out of the glucose.
01:48
So these two pathways, especially the electron transport chain, produce a lot more atp per molecule glucose.
01:55
The glycolysis makes a little bit.
01:59
So which of them would have aerobic, which one would have anaerobic metabolism? well, they will both have aerobic.
02:05
Aerobic is preferred because it produces more atp...