# Low heart rate during FF test **URL:** \ **Category:** Fitness Tests\ **Created:** [February 10, 2023, 1:43pm UTC](https://wahoox.forum.wahoofitness.com/t/low-heart-rate-during-ff-test/21673 "2023-02-10T13:43:04Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![Henk-Jan\_Kloosterman](https://sea2.discourse-cdn.com/flex020/user_avatar/wahoox.forum.wahoofitness.com/henk-jan_kloosterman/32/386_2.png) [@Henk-Jan\_Kloosterman](https://wahoox.forum.wahoofitness.com/u/Henk-Jan_Kloosterman)\ **Post date:** [February 10, 2023, 1:43pm UTC](https://wahoox.forum.wahoofitness.com/t/low-heart-rate-during-ff-test/21673/1 "2023-02-10T13:43:04Z")
After a longer period biking, I did my FF test again this week. What really was strange was my low heart rate during the 20 minute FTP. I am sure I am not overtrained, (Perhaps undertrained? If that is possible) ![IMG_0242](https://us1.discourse-cdn.com/flex020/uploads/thesufferfest/original/2X/3/3e1b96a23638a0e82b9f7da47d040bef2ce21fb8.jpeg) ---
**Author:** ![attaquer](https://avatars.discourse-cdn.com/v4/letter/a/dc4da7/32.png) [@attaquer](https://wahoox.forum.wahoofitness.com/u/attaquer)\ **Post date:** [February 10, 2023, 1:56pm UTC](https://wahoox.forum.wahoofitness.com/t/low-heart-rate-during-ff-test/21673/2 "2023-02-10T13:56:24Z")
How confident are you the data is correct? This is just a stab in the dark, but did you happen to do the test on a TT/Tri bike? ---
**Author:** ![Henk-Jan\_Kloosterman](https://sea2.discourse-cdn.com/flex020/user_avatar/wahoox.forum.wahoofitness.com/henk-jan_kloosterman/32/386_2.png) [@Henk-Jan\_Kloosterman](https://wahoox.forum.wahoofitness.com/u/Henk-Jan_Kloosterman)\ **Post date:** [February 10, 2023, 2:03pm UTC](https://wahoox.forum.wahoofitness.com/t/low-heart-rate-during-ff-test/21673/3 "2023-02-10T14:03:20Z")
No, MTB mounted on a Wahoo Kickr Core Had a Wahoo Tickr X hr sensor, and also a Wahoo Rival bowht showd about the same values ---
**Author:** ![devolikewhoa](https://avatars.discourse-cdn.com/v4/letter/d/ba9def/32.png) [@devolikewhoa](https://wahoox.forum.wahoofitness.com/u/devolikewhoa)\ **Post date:** [February 10, 2023, 2:16pm UTC](https://wahoox.forum.wahoofitness.com/t/low-heart-rate-during-ff-test/21673/4 "2023-02-10T14:16:22Z")
Other question, how much different was the test he off of your “normal” max hr, and how did the test go otherwise? Did you feel like you were going hard and was the power there? ---
**Author:** ![JGreengrass](https://sea2.discourse-cdn.com/flex020/user_avatar/wahoox.forum.wahoofitness.com/jgreengrass/32/2628_2.png) [@JGreengrass](https://wahoox.forum.wahoofitness.com/u/JGreengrass)\ **Post date:** [February 10, 2023, 2:19pm UTC](https://wahoox.forum.wahoofitness.com/t/low-heart-rate-during-ff-test/21673/5 "2023-02-10T14:19:47Z")
How did you feel during the 20 minute effort? What was the limiting factor, breathing, legs, fatigue? ---
**Author:** ![Henk-Jan\_Kloosterman](https://sea2.discourse-cdn.com/flex020/user_avatar/wahoox.forum.wahoofitness.com/henk-jan_kloosterman/32/386_2.png) [@Henk-Jan\_Kloosterman](https://wahoox.forum.wahoofitness.com/u/Henk-Jan_Kloosterman)\ **Post date:** [February 10, 2023, 2:54pm UTC](https://wahoox.forum.wahoofitness.com/t/low-heart-rate-during-ff-test/21673/6 "2023-02-10T14:54:26Z")
![IMG_0250](https://us1.discourse-cdn.com/flex020/uploads/thesufferfest/original/2X/0/03de0c3a82532e3177f576f803dd601669e3fff0.png) This was my previous FTP test. As you can see, much higher HR. > [@JGreengrass](#): > > What was the limiting factor, breathing, legs, fatigue? Fatigue, Legs (in that order) ---
**Author:** ![devolikewhoa](https://avatars.discourse-cdn.com/v4/letter/d/ba9def/32.png) [@devolikewhoa](https://wahoox.forum.wahoofitness.com/u/devolikewhoa)\ **Post date:** [February 10, 2023, 4:06pm UTC](https://wahoox.forum.wahoofitness.com/t/low-heart-rate-during-ff-test/21673/7 "2023-02-10T16:06:25Z")
Gotcha. Thanks! Definitely can see the HR is a lot lower What I would look at is: - was your power for the five min higher or lower than last time? - was the power for the 20 min higher or lower than last time by how much? If power was lower for both, and you were trying hard, then yeah, sounds like you were fatigued. But if the power was equal or higher it’s maybe different story. IMHO if you’re actually riding at FTP, legs shoukd start complaining but your breathing and Hr shouldn’t be getting away from you. If it does, likely means you’re above FTP (that’s why doing a standard 20 minute test and taking .95 sucks so bad, bc it’s by definition above FTP) ---
**Author:** ![attaquer](https://avatars.discourse-cdn.com/v4/letter/a/dc4da7/32.png) [@attaquer](https://wahoox.forum.wahoofitness.com/u/attaquer)\ **Post date:** [February 10, 2023, 5:48pm UTC](https://wahoox.forum.wahoofitness.com/t/low-heart-rate-during-ff-test/21673/8 "2023-02-10T17:48:05Z")
Ok, weird. Reason I asked was that I‘ve seen HR values get all wonky when people assume an aero position and the strap was too lose. Am I seeing it right that the HR shoots up during the recovery after the 20 min effort? Could the watch have paired itself with the tickr? ---
**Author:** ![TTDragon](https://sea2.discourse-cdn.com/flex020/user_avatar/wahoox.forum.wahoofitness.com/ttdragon/32/11633_2.png) [@TTDragon](https://wahoox.forum.wahoofitness.com/u/TTDragon)\ **Post date:** [February 10, 2023, 10:37pm UTC](https://wahoox.forum.wahoofitness.com/t/low-heart-rate-during-ff-test/21673/9 "2023-02-10T22:37:03Z")
Something is off with that data. The heart rate jumps back up after you had the break after the 20 min effort but before the 1 minute effort. Equally your HR never went up when you started the 20 min section. The 20 min section looks wrong. Does the battery need replacing in your HR monitor? Could there have been interference in that section? Did you turn an extra fan on for that part?