Depends on two things:
1. Quality of instruction
2. How much you practice
Things to remember that may help speed things along:
- Relax with intent - not wet noodle relaxed. If you feel tension building, STOP, do something to loosen up and then start again. Relaxation cannot be over emphasized. If you move with tension it's like trying to drive with an emergency brake on.
- Make sure that the body structure is properly aligned - the less muscular force used = more free circulation of chi
- DON'T RUSH - it will take a while to correct your posture and open channels in which chi flows
- All in all, w/ good instruction and practice you may begin to 'feel' things within at least 6 months to 1 year. Be diligent and RELAX RELAX RELAX. After a few yaers in kung fu, relaxation has been the most difficult thing for me to acheive.