Low resting HR translates to lower Metabolic rate? - anyone else have experience

As the title says… anyone else have any experience with low average HR and BMR and Daily MR

I have avg Daily HR of 41-43 BPM, and have just started wearing a Garmin Watch with HR tracking.
The unit states I am burning approx 2000- 2200 Cals daily NOT including training. This is just life/work/kids etc
Im 39 years old,
6 ft 1,
93kgs,
19% BF,
360w FTP,
42.5kgs Skeletal muscle mass from a recent body scan.

Always struggled to drop weight even with a good diet and training…, always had a very low heart rate even when not trained.

Could this be why?

41-43 all day hr?? I think unlikely to be honest. Resting possibly.

Re calories it is a guesstimate but personally I prefer to calculate my own to get the TEE which is bmr + pal + tef

1 Like

7 day daily rolling avg HR Is 41-43

Have had low HR, sometimes it gets up, when I’m asleep it goes down to 33-37 bpm

Your garmin is broken or you need to get to a doctor asap.

MY HR has always been super low since first noticing it in late teens.
Regular check ups, Blood pressure all good, nothing frightening, as with different HR monitors i can get it down under 40 bpm first thing in the morning with concentrated relaxation.

Currant Max HR is 186ish, Threshold is 165-170 bpm

I would have presumed that a low resting HR is more about cardiac efficiency than metabolic activity, but who knows.

The bigger question: if you knew the answer was yes, what would you do about it? You’d increase your estimated caloric deficit if you wanted to lose weight, right?

A low RHR does not imply a lower metabolic rate, only an efficient heart stroke. HR’s link to metabolism is relative – when you raise your HR to 100 BPM (say), you’ll be burning more calories than someone of the same size/BF who has an RHR of 70 (say).

Your Garmin is most likely underestimating your calories. Based on your body metrics, your RMR is around 1,960 kCal/day; if we assume you burned 2,200, per your Garmin, this gives you a PAL multiplier of 1.12, which is too low even for someone who literally lies on the couch and watches TV for all of their waking hours. Spend some time looking through the Compendium of Physical Activities: https://sites.google.com/site/compendiumofphysicalactivities/home

Even desk work has a PAL of ~1.5. Try making a hour-by-hour breakdown of your typical day per the one done here, and you may be surprised by your average PAL: http://www.fao.org/3/y5686e/y5686e07.htm . Even a modest average of 1.4 puts you north of 2,700 kCal/day typically.

If you’re actually eating 2,000-2,200 kCal and aren’t losing weight, it’s probably because you’ve tanked your metabolism.

1 Like

awesome… thankful for the response.

What Garmin again? I just don’t believe it sorry…

All good, you don’t have to believe it.
Ive had a Polar watch, Garmin edge 500,800,530, 3 different Chest straps, Garmin vivomove HR, used my wife’s forerunner and a had a doctor comment when i was younger before i had surgery say “your the kid with the low HR”,

so not new to me in anyway, just investigating and trying to learn about how my body works.

My RHR fluctuates between 38-42. Usually low 50’s when at rest in the day
I’ve always struggled to lose weight, although I’ve never really stuck to a rigid diet for too long.
I started using My FitnessPal at the beginning of August and saw good results in the first month.
September has slowed down quite a bit even tho I’ve kept to the same calorie intake (1800+ 50-75% exercise calories) I still complete all my workouts so will consider dropping the percentage in October if things don’t progress. I should try and improve my diet a bit too.
I’m more determined this time but have always thought I lose weight slower than expected.

What is your height/weight/approximate BF? Unless you’re very short or older, your weight loss most likely stalled after a month because you’re drastically underfeeding.

1 Like

Currently 104kg , 180cm. Haven’t a clue what my BF is.
I did think I was not eating enough, had a week or so of eating more (but still within MFP target) and gained weight.🤷
I’m not always 100% accurate with my counting so usually err on the side of caution regarding my intake.

I think you meant to say in your initial post your average resting HR is low 40s not your average daily HR(for the entire 24hrs).

I was thinking you were averaging low 40s for the entire day, workouts included

I’m a similar build 6’3" and 90kg - down from 92 3-4 weeks ago. My scales tells me I’m 12% but I’d think that isn’t a million miles off you considering the scans tend to report higher percentages. My RHR is low 30s, I’m usually mid 40s during the day. Max is 188 but threshold is low at ~160.

The main difference for me has been sleep quality. I’ve had a few months of longer runs and bikes over the last 2-3 months and have seen some body composition changes. But the real drop has only come in the last few weeks where I’ve been a lot more disciplined with my sleep regime.

Lack of sleep plays havoc with your metabolism, hormonal release gets thrown out of whack - can make it very difficult to shift weight.

2 Likes

That will be my problem then, I never get more than 6-7 hours plus a snooze mid afternoon.
I am still losing weight, just slower than I would like.

1 Like

You’re eating far, far too little. Any weight you “gained” in just one week’s time of eating more is undoubtedly water weight or scale error, unless you were genuinely binging.

Seriously, your body will quickly go into starvation mode with that kind of intake coupled with training rides for any consistent length of time. You’ll sabotage your fat-loss because your body is hanging onto every calorie, and you’ll also bury your metabolism and probably hit a hard wall in your training. Decent chance of nuking your Testosterone levels too.

1 Like

I too have a “low” resting heart rate and the week average with Garmin is usually in the 36-40 range.

I do not think this effects metabolism however because the amount you move is more important than your heart beats for resting metabolism. Otherwise without movement in the equation basic metabolic functions of the body don’t have a huge difference.

One thing to mention that Amber always is so good about is never dieting on the bike, or around training. This is where your body needs extra and will use so as fuel, not for fat. Use zone 2 rides for fasting and getting into a caloric deficit but you are severely under training if otherwise you aren’t feeding.

One common phenomenon is someone who is in a caloric deficit from training subconsciously adapts for it by not moving as much the rest of their day. This will try to equalize the calorie deficit.

I have found better training and weightless when eating more whole foods and carbohydrates to replace what I burnt in a training session. A bowl of oatmeal, a smoothie, etc.

Prior to a training session restore the deficit you have been in with a quick carbohydrate snack like a bar, a sandwich, etc. and feel good about training hard, there will be an opportunity here to get more fit.

1 Like

Thanks for taking the time to provide advice. I will definitely take it on board and focus more on the accuracy of my diet.
I’m not suffering with hunger as I have done with previous diets, I’ve also been performing well on my workouts so don’t think I’m too far away from a decent balance.
On workout days I’m consuming well over 3,000 cals, is that seriously under eating? Doesn’t feel like it.
Thanks again for your input.

1 Like

Depending on your age and approximate BF%, your RMR is probably in the vicinity of 2,100-2,200 calories based on your height and present weight. This puts you at around 2,700-2,800 calories per day with a highly sedentary lifestyle (I’m talking 8-9 hours of desk work followed by 5-6 hours of TV watching). I don’t know your FTP or intensity, but if you’re doing TR workouts you’re probably doing at least ~500 kJ of work in each, which will converts to about 80% of your calorie burn (the standard convention of kJ = kCal does not quite account for the correct general metabolic efficiency of cycling, which is closer to 20% than 25% for most individuals).

So, 3,000 kCal/day is not a difficult barrier for you to break. If you’re genuinely eating 1,800 kCal/day + 50-75% of workout calories, this puts you at a regular caloric deficit of well over 500 kCal/day, which is a recipe for all kinds of trouble (including the stalling of your weight loss in the long run because you’re tanking your metabolism). The general rule of thumb for weight loss is not to exceed a 500 cal/day deficit, but bear in mind too that the stress of training will impose an additional recovery demand in your body.

2 Likes