Heart Rate Variability

I'm a 39 year old male and have been riding my mountain bike on the road and hike and bike trails consistantly for about 9 months. I got an HRM a few months ago. My resting heart rate gets down to about 50 bpm. I ride for about 45 min 2 to 3 times a week in a target zone of about 130-150bpm. I've noticed though that on a given day I can ride the exact same ride at about the same pace and one day I'll average around 140bpm and another day I'll average about 120bpm. My perceived effort feels around the same and if anything on the days that I average 120bpm I may feel a little more winded than on the other days.(Though not really by much) Is this variation normal, or can there be some explanation for it? Thanks.
 
I'm a 39 year old male and have been riding my mountain bike on the road and hike and bike trails consistantly for about 9 months. I got an HRM a few months ago. My resting heart rate gets down to about 50 bpm. I ride for about 45 min 2 to 3 times a week in a target zone of about 130-150bpm. I've noticed though that on a given day I can ride the exact same ride at about the same pace and one day I'll average around 140bpm and another day I'll average about 120bpm. My perceived effort feels around the same and if anything on the days that I average 120bpm I may feel a little more winded than on the other days.(Though not really by much) Is this variation normal, or can there be some explanation for it? Thanks.

I have a Polar HRM that I think is quite consistent. I can go indefinitely at 130, until my legs give out, and that is my lower target rate. From 135 - 145 I am struggling for air and cannot hold a conversation but can go on for an hour or so and I cannot go faster than 145 for any sustained period. My results are fairly consistent, although there are days that I get winded at a slower heart rate.

Exercising in the 130 - 150 bpm range is very reasonable for your age.

And, are you measuring the heart rate with the heart rate monitor? 50 resting bpm at age 39 is quite low.
 
Measured with an HRM, I get 52 consistantly and as low as 48 on occasion. Though only after laying down and relaxing as completely as I can. I guess my real question though was if it is normal to have such a variation in average heart rate while trying to do the same exercise.
 
Your heart rate varies much more than mine with the same exertion. Mine only varies by maybe 5 beats.
 
Your heart rate can vary for a number of reasons:
Illness, lack of sleep, caffeine, stress, too hot, too cold.

20 bpm seems like a wide variance. One thing i notice is that a por connection to skin (lack of sweat / moisture) can cause my monitor to jump around. I use little lotion on the strap and usually solves the problem.

Also, your resting HR is fine for your age. I am 37 and mine will get in the 40s when totally relaxing, esp. in the a.m. My max is 188 (although I almost fell over "testing" this).
 
Yes, depending on the condition of your body your heart rate will respond to exertion differently.

Caffeine will cause the HR to increase with relatively less exertion.

As your fitness increases the same exertion will cause a lower heart rate.

However, should your heart rate be sporadically different with no rhyme or reason such as those listed in the first half of this post or in other posts, I would make sure that you are exerting yourself to the same extent.

Bike riding can tricky because you can easily cheat on the exertion through body positioning and form and still feel like you are at a relatively high aerobic level.

For instance, bouncing up and down on the seat makes riding much easier than if you were statically moving with and exerting a constant force on the pedals. The two can seem aerobically similar since you are pedalling at the same speed.

If you are exerting the same amount of force and your body is in a similar state in all workouts then I would ask a your GP for his/her opinion.
 
Back
Top