bill0996. I have a Boston Scientific. The newer ones have sensors. Mine had a motion sensor (newer ones have different type sensors) and when motion went up heart pacing would increase. It can be set how sensitive it is and how much it rises.

I did not get any benefit from it meaning I did not feel any different during exercise. It was working as they could see it from my pacemaker checks. On the negative side I started having some episodes right after they turned it on. I had them turn it off and the episodes (knock on wood) stopped. Can's say it was the cause but stopping it stopped the episodes.

I have tons of PVCs, my heart is paced to 70 (resting pulse 54) to help reduce PVCs and told a very strong sinus mode (natural pacing of heart). What I worried about was so many electrical signals coming in was causing heart to go awry. Again not a EP but since it was not helping me exercise (I am very active and do Sprint Triathlons) had it turned off and episodes stopped.

Your EP and Pace Clinic should have advised you of this function if you have it in yours. If you have a pacemaker you can always go on their web site and put in your model and date and can get a lot of information on your pacemaker and ICD if you have both (I do).