Roadie,
Thanks for the post.
I think you are focuising too much on your heart rate. First, there is no set criteria on exactly what your heart rate should be when you exercise. I generally advise my patients to limit based on percieved effort and not target heart rates. Also, if you are using a heart monitor to measure your heart rate, they are notoriously fickle when exercising.
Im not sure what your target weight is. If you are exercising as much as you state and eating appropriately you may be at target weight. I would discuss any weight loss program with your physician.
good luck
My heart rate does exactly the same thing. Immediately when I start my jog it jumps to 135 bpm. Then it stays in 170's or 180's for my jog. I have been checked by cardiologists. I am fine.
Don't let people frighten you unnecessarily especially when they don'y know what they are talking about, get checked by your doctor or cardio before assuming the worse, I have a similiar problem that has responded to a beta blocker. I have what might be called a mild case of IST(inappropriate sinus tachycardia) other than that my heart is normal. While the fast heartrate can be uncomfortable and even exhausting at times it is only a rare case that IST causes cardiomyopathy.Check with your doctor, a beta blocker might be worth a try in your case.Good luck.
The doctor's comment is well taken about the accuracy of heart rate monitors, but I have found them to err only when some arrythmia is present. My experience is when I get PVCs, the monitor cannot determine a stable average beat to beat, so it refused to update until it sees 4 or 5 beats in a row without a PVC. I don't think you are dealing with this and would guess the monitor is accurate. Its easy enough to check though by counting your pulse after come moderate exertion like climbing a flight of steps and comparing to the monitor.
One error I have found with most of the monitors is that the wireless ones tend to pick up the transmissions from wireless fences for pets. That error tends to be a static type of thing though where it will suddenly read like 234 while you pass by a certain house and then go back to normal.
I am an experience rider with over 30 years and find that I cannot maintain of pulse rate of over 140 or so for an extended time (my legs are screaming). Sprinting or significant climbing takes me to max of 180 or so but only very briefly since it is very anaerobic.
Without being judgemental, my guess is that you are not in as good of shape as you would like to be yet. Exercising at a pulse of 190 to 200 is not a good way to gain aerobic fitness. I think the concensus is that you should be at 60 to 80% of max heart rate for aerobic gains.
I should mention that I have seen atrial fibrillation result in the kind of heart rates you are talking about. I have had it myself and know of other riders also. Normally though people seem to have normal rates at rest and early on in a ride or during exercise but suddenly experience the high rates when the Afib sets in. You suddenly start feeling really lousy with dead legs.
I guess there is a possibility that you are in Afib all the time and don't know it. An EKG could tell this immediately. I find that I can tell by how uneven my pulse is (and how lousy I feel and the inappropriately high pulse rates during exercise).
Have you had any thyroid testing done? People don't always lose weight when hyper thyroid and it can cause an elevated heart rate. It might be worth a shot.......