Thanks for all your tips, its until last week that I actually decided to start training my core. Never been a fan but now that I really want to get fit ( I know I'll never look like a pro bodybuilder since I put more time riding than resistance training) the core will help out. As for the stretching you are absolutely right. Thank you for reaffirming my thoughts. @Lexi01 you might also be right, My left knee always gives me some problem but that is mostly because I am prone to getting a tight IT band often so I guess I need to take out my foam roller and work on the stretching. Thank you all for your tips and help!