I did some weights for the first time in about a year. I m a smoker and I ve noticed that I sometimes feel palpitations. My heart will beat irregularly even after masturbating. Basically my heart just feels really weak for about 2-4 hours after I exercise. It felt like it was beating fast, but wasn t quite getting the job done. I also felt really aware of how it was beating, if that makes any sense at all (probably doesn t). Pretty strange feeling. It still feels kind of tender, but I can t tell if I m just making it up, or if it really does still feel like that. I couldn t sleep at all last night, so the fatigue may have something to do with that. I m also still fairly short of breath, which does have me a little concerned.