Take the 2-minute tour ×
Physical Fitness Stack Exchange is a question and answer site for physical fitness professionals, athletes, trainers, and those providing health-related needs. It's 100% free, no registration required.

This question asked about using pulse as a measure of fitness. Resting pulse seems like a nice, simple way to do this. But I find that my resting pulse varies by a huge amount, from values as low as 63 per minute to as high as 83. How much does it normally vary based on time of day, posture (sitting or lying down), or caffeine? If it has this much variation that's hard to eliminate or account for, then it seems like maybe a different measure of fitness would be more appropriate, such as the time required to run two miles. Or if you do use heart rate, what is a better measure of fitness, the average of a series of measurements, or the lowest?

share|improve this question
add comment

1 Answer

Heart rate is extremely variable, and can go up or down with environmental factors such as heat or cold, foods containing stimulants like caffeine or depressants such as alcohol, standing up versus lying down/sitting, etc.

The two ways that I usually use to recommend for using pulse as a gauge of fitness and/or overtraining, is to take it every morning as soon as you wake up, and after workouts, take it immediately after the workout and again 3-5 minutes later.

The morning one should stay relatively the same, or even drop as your fitness gets better, and the one post workout should drop dramatically within a few minutes. If your morning pulse rate starts going up, or your post exercise rate stays elevated, then you have some factors influencing the rate. This could be dehydration, fatigue, overtraining, life stress, any number of factors.

As an example, my morning pulse rate varies between 45-55, and my working heart rate will usually drop 40-50 beats within 2 minutes (Depending on intensity of workout). As long as you are consistent about when you take it, and track it over time, the trend will tell you if something might be off.

References:

http://www.ncbi.nlm.nih.gov/pubmed/23477780

http://eurheartj.oxfordjournals.org/content/27/20/2387.full.pdf (Some discussion of extrinsic vs intrinsic factors)

http://www.sciences360.com/index.php/factors-that-affect-heart-rate-2-8360/

http://www.colorado.edu/eeb/courses/1230jbasey/abstracts/farah.html - Looking at an exciting picture raised heart rate

http://www.nature.com/jhh/journal/v16/n5/full/1001398a.html

share|improve this answer
    
This is a helpful answer, so +1. But it would be nice to have some more quantitative info from a more authoritative, published source. –  Ben Crowell Nov 26 '13 at 20:41
    
@BenCrowell - I have listed some references, but a simple google search for "external factors affecting resting heart rate" or "environmental factors" etc. gives quite a few. Emotional state, hydration, external temperature. altitude, sleep status all can have an effect. –  JohnP Nov 26 '13 at 21:05
    
Thanks for adding the references. The one by Farahmandifard does give a number: seeing an exciting image raised heart rates on average from 66 to 74 bpm. But the rest either seem to be paywalled or not very relevant. Schnell is paywalled, and the abstract doesn't give any numbers. Siribaddana doesn't give any numbers. Rabbia compares different people. Cook is interesting but not on topic. –  Ben Crowell Nov 27 '13 at 16:00
    
@BenCrowell - You're not going to find hard numbers. Even the farahm et al is an average. Heart rate is extremely individual, and extremely affected by environment. I can stand behind you and say "Hey, I'm going to randomly jab you with a pin" and your heart rate will rise. There's just no way to say "Ok, 10 degrees warmer will produce a 6 beat jump in HR". –  JohnP Nov 27 '13 at 18:03
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.