how long does it takes for our body to improve stamina?

Question: how long does it takes for our body to improve stamina?
- Keywords:
  body,
  stamina,
  time
Asked by rafi8 to Gavin on 12 Mar 2012.
- Gavin Devereux answered on 12 Mar 2012:
  
  It can happen very very quickly.
  
  Some studies using exercise training have shown that just a week or two can have a positive impact (exercising 3 to 5 times per week).
  
  It tends to depend on how highly trained the individual is before they start trying to improve stamina. The quickest changes tend to happen in people who are untrained (called sedentary) before they start an exercise programme to improve stamina.

Question: how long does it takes for our body to improve stamina?