I am a 55 yr. old woman. Three days ago I did several sit up crunches and reverse crunches. I then went in a took a bath. I noticed it was it was very hot, but did not think it would bother me as long as it was not hot enough to burn you. I was in for about 10-15 min. and since that evening I have had off and on heartbeats that I can feel inside my chest . If I go up or down the stairs it starts, even last night relaxing in bed it was off and on. Today, I am feeling better. It did not bother me at all this am but it is now 3pm and if I do too much it starts to beat harder. (It reminds me of the 1and only time I was in a hot tub ) and I felt weak and my heart felt like it was beating in a fluttery sort of thing. This is now the 4th day with this on and off feeling, with no other symptoms. I do not have insurance, but hope to soon, when my husband starts a new job. Could these prior activities have anything to do with how my heart has been?