Hi,

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I was wondering whether anyone has been experimenting with purely nasal breathing and heart rate monitoring.

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I am 33y old, so my MAF heart rate is 180-33=147. According to the guys like Maffetone, Sisson etc, this is the heart rate I shouldn’t surpass during base building and the majority of my workouts. Now, in their books they also frequently say that an easy way to make sure one doesn’t slip over this heart rate is by purely nasal breathing during running.

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I tried that the other day and I was easily able to run at an average heart rate of 165 while only breathing through my nose. Even 169 was not a problem, a whopping 22 beats above my MAF rate.

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Any ideas what this signifies if anything? Am I a genetic freak?

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I am measuring the heart rate with a Garmin HR TRI chest strap, which is quite accurate.

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For context:

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• Right now decently fit (VO2 max 56). 5k = 20 min probably
• Ran Cologne marathon exactly 1 year ago in 2:48h, 5k sub 16:50. VO2 max back then was 66.
• have been on a ketogenic diet for 65 days, but no clue whether this would affect heart rate and breathing!?