Yes it definitely does. Try looking up endorphins and exercise and you should find a lot.

More than drugs.

Particularly after a modest workout (unlike 2 a day hell week work outs for football) serotonin is flowing regularly through out the body and a nice constant rate. That’s all I know. That and I always feel positive about life after a 3 mile jog, or any jog for that matter. Typically, people with low levels of serotonin are classified, “depressed.” And that’s what those anti depressants do, is fill in the void of serotonin. However, since the body isn’t naturally releasing it, it isn’t always in sync and the blood flow isn’t always constant. This is why some anti depressants don’t work and leave the person feeling null and void, yet they are conscious of what’s going on, it just isn’t natural however. The negative effect of taking anti-depressants is that ones body becomes dependent on the substance and the brain part responsible for triggering the release of natural serotonin through out the body starts to slow down as it doesn’t need to be on much. So when an anti-depressed person gets off that stuff, they usually get back into depression or have a hard time seeing the light of day.

“According to the National Institute for Health and Clinical Excellence, of the United Kingdom, exercise increases brain serotonin function in humans. A study published in Neuropsychopharmacology revealed that there are two mechanisms by which physical activity increases brain serotonin. First, motor activity increases the rate and frequency at which serotonin is “fired” within the brain, resulting in an increase in both the release and synthesis of it. Secondly, regular exercise increases the level of tryptophan in the brain (an amino acid used to manufacture serotonin). The exact mechanism is not clearly understood; however, it is clear that aerobic exercise improves mood through increasing brain serotonin levels.

Source

The question I would ask is not whether if exercise affects serotonin levels, but if it does affect serotonin levels, then so what?

@Rarebear Perhaps you could elaborate as to why you’d ask it that way?

@Rarebear If I’m understanding you correctly, you’re wondering why people would care about levels of serotonin in the brain and how exercise effects those levels. Serotonin has been linked to depression, meaning that people with lower levels of serotonin tend to be depressed. If we take this as true, then it would be very advantageous to know what things effect serotonin levels in the brain, since this would also be affecting depression levels. It’s an interesting finding that exercise increases serotonin, since this would suggest exercise as being a remedy for depression.

@RedmannX5 One does not necessarily lead to another. SSRI certainly effect serotonin levels, but they’re local levels. Does serum levels of increased serotonin yield decreased depression? Would an IV infusion of serotonin decrease depression?

Let’‘s say for the sake of argument that exercise did increase serotonin levels.

A = serotonin levels
B = decreased depression
C = exercise.

If A then B? Not sure. Let’s say yes.
If C than A? Not sure. Let’s say yes.
Then if A yields B, and C yields A, does that mean that C yields B?

My point is to be scientifically rigorous, you need to test each arm individually, and not make assumptions.

Fair enough, and I guess that is what I’m wondering then. The truth. That is a better answer if there has been such a study. Are you aware of one?

No, I’m just musing and being an annoying skeptic. Sorry about that.

@Rarebear But many SSRIs are prescribed for depression. Are you questioning their effective or only natural increases?

@janbb No, you’re missing my point. There is no question that SSRI help depression. And they do increase local serotonin levels. See my post regarding the A,B,C above, read it closely, and if you still don’t understand my point I’ll try to elaborate.