I am a 60 year old female, good health, exercise classes 3 x week, gluten & dairy intolerant, eat a well-balanced diet.
Occasionally I notice a fast heart rate. I purchased a Fitbit HR to track it. Resting/relaxed heart rate is 62-65. One night last week after being in bed about 10 minutes, I felt my heart racing. Heart rate was recorded at 125. After it calmed down, it went back down to 65. What does this mean?