Its the same thing haha there are two types indica and sativa. Indica makes you tired and want to sleep while on the other hand sativa relaxes your body.
As an energy source, To heal and build and repair tissue, To sustain growth, To help transport oxygen to the cells, To regulate body functions. hope this helped :)
Stretch your arms before stretching your chest and you might want to throw some joint rotations in there
The only guaranteed method is abstinence
Dual Energy X-ray Absorptiometry (Dexa)