Home Chat General Chat

Heart rate

Dear readers,

I am a beginning to train train for my first triathlon. My height is 168cm and weight is 62 kg. I regularly run 5km under 20 min. However, during each training and/or race my heart rate drops after 15 min (consistently) from 165+ to around 120. I do finish my trainngs and races. I have no symptoms shortness of breath, chestpains, dizy or other cardiac symptoms

My hometrainer trainings consist of 1 hour trainings at around 160 to 180 watt. My heart rate does not drop below 160. I have no medical conditions (that I am aware of) and am a healthy 28 year old male.

Do other people have similar experiences?

kind regards,


  • I'm not a doctor (but am an engineer!).

    Initial thought is that your heart rate monitor isn't reading correctly, rather than 'real' hr drop.

    Are your figures from the HRM or checking your pulse 'manually' ?

    If a HRM using a chest strap, sometimes the contacts from the strap onto your chest can get dry and not work well. Alternatively if the strap is old the fine wires insideit can have corroded / cause errors reading.

    I've had both problems.

    Try wetting the contact points (where they contact your chest) on the strap before use.

    And hand wash after use to remove salts from sweating.

    If using an optical HR (eg on latest garmins like 735 and 935) then they too can have errors / inconsistencies. Just google something like 'optical HRM problems' and youll see more.

    Worth just doing a simple manual comparison of HR when it drops, (eg beats in 15 sec then x4) to see if its a real heart rate drop or just the device giving a false reading.
Sign In or Register to comment.