The stimulant you are describing is methamphetamine aka meth.
Because you want to keep the momentum and tempo of your arms with the drive and finish of the kick
Stiff muscles are related to low joint movement/flexibility. They respond slower than loose muscles.
Answer:
1. vagina
2. period
3. sperm
4. divides
5.
6.
7. fetus
8. placenta
9. umbilical
10. belly button
I'm not sure if this is correct, but I think for the most part it is. hope this helps :)