I'm just wondering if any larger busted ladies have problems using the Garmin HRM strap. I'm guessing my larger assets are moving the strap as they move (even though they are gagged by two sports bras) This is becoming more and more frustrating as I really like training for the marathon using a HR programme. I've changed from the original strap to the new softer one but still loses the readings into the run. Please any advice other than swapping running for glamour model...?!!