Yes it does, but that does not mean it's bad. This weekend while cheering on Tani and watching runners come through the first aid station during TNF's half marathon in DC, I read the following quote on the back of a man's shirt.
I have not stopped thinking about it all week. I did a little search and apparently it was originally said by General Lewis B Puller who was a U.S. Marine. What he may have meant was, that if you work through the pain it is strength that will survive the pain.
I honestly don't know what that means to General Puller or anyone else for that matter. I do know this...
After I have run for a day, or even two
When the sweat has dried and nausea fades
My feet are swollen and blisters are full
And my legs feel beaten and stairs seem like Everest
I have washed the trail dust from my body
Life seems anew
The beer is crisp, the hugs are warm
I feel fresh, so incredibly empowered and stronger than I was before.
At these moments I am so aware of my body and my mind feels forever clear.
Perhaps all the weakness is gone. Maybe it was never there and I just need to run to remind myself the strength is right there where I left it.
Do what ever it is that reminds you of the strength you have.