Hi @digininja - great question! While on average, we typically see about a 10 beat/minute difference between cycling and running threshold heart rate…with running being higher than cycling. That being said, there are individual differences that can either decrease or increase that difference. If you have a very significant running background/history and are new to cycling, I’ve often seen closer to a 15 to even 20 beat/minute difference in LTHR - with cycling being lower. On the other hand, folks with a more significant cycling background/history and minimal run background can see just a 5 beat/minute difference in LTHR or even less. So, while 10 beats/minute might be average you can use your rating of perceived effort (RPE) to cross check…generally speaking your FTP should be at the same 0-10 effort (usually about 7.5 out of 10), so you can use that to compare. Also, in addition to the heart rate differences your breathing can also be a giveaway. Right at FTP/threshold your breathing should be fast but still controlled. If your breathing is beyond that level of control and you’re gasping, then you’re above threshold. Hope that helps you!