Hi Thank you for asking HCM. I have gone through your query. Tread mill test also should be done to rule out exercise induced ischaemia. If that is also clear then it can be most likely due to costochondritis. Palpation on rib area will be painful for this. For such condition applying anti inflammatory gels containing ketoprofen, methyl salicylate and capsaicin locally will be helpful. Oral ketoprofen can be taken if pain is more. Modifying the posture of your cycling will be helpful also. If still pain is there then local injection of corticosteroids or anesthetic will be helpful. Hope this may help you. Let me know if anything not clear. Thanks.