Is it me, or my HRM, or only me pretending?

Do you have a natural abnormally low heart rate?

No. I am at the risk group for hight blood pressure (145/90) Not taking for it any medications yet. But do taking medications for high cholesterol. Maybe that?

What are you taking for your cholesterol? Are you taking any other medications besides your cholesterol medication? Depending on what you are taking, there can be a heart rate effect, especially if your doctor was trying a combination therapy to lower your high resting heart rate at the same time.

I'm taking Crestor 5 mg every evening, and two soft gel capsules of fish oil (Omega defend). That's all.

Okay, just double checked and Crestor isn't one of the antilipidemic agents that can effect heart rate.

I've got the same issue and also use a Garmin Forerunner. But I had the same issue when I used a Polar too. I always assumed it's because I'm not that heavy to begin with. Sometimes, I still wonder if the calorie readings are low, but I figure that's better than having readings that are too high.

if it helps you to help me :flowerforyou: , (I hope photos will show up correctly):

1. this one bellow is from my interval running training few days ago (40 min, av. HR 120, max HR 157, 236 cals total) => I ran 500 m fast + 2 min rest








2. here is my HR from yesterday (2 hours, av. HR 100, max 143, 422 cals total) => first hour is weight lift, second is cardio.

Okay, looking at the first graph, this looks like a standard HR response to interval training, with the exception of the drop at the 8:20 mark. I'm guessing here, but it looks to me like there was some interference in the monitor reading your heart rate at that point. If it is having trouble reading a heart rate at one point, then the other data become questionable. If we were to superimpose an oxygen consumption graph over the top of it, the oxygen consumption would be more stable and have fewer hills and valleys because it is interval training. A HRM is really inaccurate for Calorie estimation of interval training because of that.

Looking at graph 2, you can clearly see the delineation between the weight training and cardio, although you can also see some places where it clearly drops out and isn't accurately reading the heart rate, most notably at about 5 minutes, 1 hour 30 minutes, and 1 hour 56 minutes. The sharp saw tooth pattern is typical of the weight training where heart rate goes up and down with each set. The oxygen consumption graph overlaid on this part of the graph would demonstrate working above your VO2 max and creating a very high oxygen deficit that is made up for after the exercise is completed. The latter part of the graph demonstrates that you were either doing another interval type cardio workout or the HRM was dropping out and not reading your heart rate about half the time. Either way, it makes it impossible to get an accurate Calorie expenditure estimate.

Personally, instead of using this HRM, I'd use the METs compendium and estimate the Calories based on the activity and duration. You can find the compendium we used in my classes at: http://prevention.sph.sc.edu/tools/docs/documents_compendium.pdf

To estimate Calories, you multiply your weight in kilograms by 0.0175 and the MET level to get Calories per minute. Then multiply by the number of minutes to get the Calories for your workout.

So, as a guide, saying you were weight training for 60 minutes and it was standard weights not heavy enough to be considered body building, then I would use the MET level for weight lifting, light or moderate effort, which is 3 METs. Followed by 60 minutes of interval training, which is on the compendium as circuit training and 8 METs.

Weight Training:
kcal/min = 0.0175 x 3 x 58.96761317 = 3.095799692 kcal/min

kcal/hour = 3.095799692 x 60 = 185.7479815 kcal

Interval Training:
kcal/min = 0.0175 x 8 x 58.96761317 = 8.255465844 kcal/min

kcal/hour = 8.255465844 x 60 = 495.3279507 kcal

185.7479815 + 495.3279507 = 681.0759322 Calories burned for the whole workout.

And for your running, I would use the ACSM running formula to get an estimate to verify the HRM numbers. If you have an estimate of miles per hour and the % grade of your running surface, I'll be glad to do the math for you.

Last time I ran 5.6 miles per hour and the running surface was totally flat +/- 1 m. does' it help to calculate? i ran 60 min total, 5.7 miles.

Okay, here's the math.

VO2 (ml/kg/min) = (0.2)(5.6)(26.8) + (0.9)(5.6)(26.8)(0) + 3.5
= 30.016 + 0 + 3.5
= 33.516 ml/kg/min

METs = 33.516 / 3.5 = 9.576 METs

kg = 130 / 2.2046 = 58.96761317 kg

kcal/min = 0.0174 x 9.576 x 58.96761317 = 9.881792615 kcal/min

kcal/hour = 9.881792615 x 60 = 592.9075569 Calories burned from this run.

Now, I may be biased because I'm an ACSM Certified Clinical Exercise Specialist, but I trust the American College of Sports Medicine estimations over a heart rate monitor. So, based on this, I'd return your HRM because it isn't accurate for your runs.

Tonya where you been hiding? How did you pull Vo2Max from that? I don't see where you would get the mL of oxygen to calculate the VO2 max...

I'm not hiding. I'm just up to my eyeballs in books because I still have the NSCA CSCS test this month.

And that isn't the VO2 Max. That is the VO2 (volume of oxygen consumed) for this particular exercise. VO2 Max can't be extrapolated from this because it is not a standardized test, just a workout. This is an estimation of the volume of oxygen that is used during this activity. From that you can get the Calories by dividing by 3.5 ml/kg/min to get the MET level and then plugging the MET level into the kilocalories per minute formula of 0.0175 x METs x weight in kilograms.

I have two things to say to the OP.

One: some people that are burning mega calories are extremely overweight and therefore it burns at a much higher rate. Some people log that they burn 800+ calories doing Zumba. According BOTH my Fitbit and my HRM, I only burn around 325. But I only weigh 135.5

Two: Most people are full of *kitten* when they say they burned these incredible numbers and are only fooling themselves. They overestimate or rely upon the treadmill only to tell them what they've burned, which is notoriously WRONG.

agree

Since I got my HRM (Garmin Forerunner 110, I think the good one), I noticed that actually I burn far less than I thought.

But not THAT less:

Yesterday I did almost two full hours of very heavy exercises (1 hour of workout with all of the squats, side and walking lounges with weights, 30 pushups and back pushups, etc + 1 hour of cardio interval training), I was socking wet, didn't give my self rest, I mean it was REALLY hard workout for a day, and I got ONLY 422 burned calories for that???

My highest HR was 148, average is 100. But, only 422 cals for two hours?!

Few days ago I was running for an hour, with highest HR 154, average was 120, and got only 234 cals... What is wrong with me? Am I just pretending that I workout hard?

or it is just my HRM?

I see people are burning up to 800 for one hour, geez, I should do 4 heavy hours for that...

What do you think? can you see anything from these data about my HR?

one more thing, is that you in the photo? if so why do you really care? YOU ARE SKINNY!!!

True, the formulas could be completely wrong. But, at least the ACSM will site the research where their formulas were derived and will give you the formulas to determine your own numbers. Not so of heart rate monitor manufacturers who site them as "proprietary". Proprietary is suppose to mean that it is their own special formula that no body else can use, but in actuality it ends up being a secret that no body else can verify as accurate. Speaking of accuracy, the talk test is notoriously inaccurate. It's a general estimation for when there are no other methods to estimate intensity. For example, I did a metabolic test in our Ex Phys lab where I was having VO2 and respiratory exchange ratio measured and was at the lactate threshold while still at an RPE of 8 on the 6-20 scale (RPE being the standard scale used to estimate intensity level similarly to the ability to talk). Not only could I still talk, I could have still sung had I not had the mouthpiece for measuring O2 and CO2 in my mouth. I wasn't out of breath or having even the slightest loss in ability to talk until after I had surpassed the 2nd lactate threshold. If they had gone by the talk test, I wouldn't have been at my 1st lactate threshold until I was almost at my VO2 Max.

I am confused by this...as you know Lt zone boils down to the ability to use oxygen. When Lactate can't fully be buffered it starts to build up, which also increases the the need for O2. This as you know is your LT. If you're not in oxygen debt you're not in your LT zone. That's really the difference from aerobics and anerobics. If you can sing, you have enough oxygen, you're not really in oxygen debt so you're not really in your LT zone. You'd probably tell me about some physiological adaptation, but I can't see that working either.This will probably end up in to a kreb cycle discussion. So i'll start it now...

Fatty acid's require oxygen for break down to pyruvic acid, then the kreb cycle converts the pyruvic acid to CO2 and H2O. Fatty acid's won't break down without oxygen as you increase your intensity more glucose will be used oxygen will be limited and the glucose converts to pyruvic acid and turns in to lactic acid if there is no oxygen. So as I said to produce Lactate acid oxygen won't be available.

Not saying the test is wrong, what i am saying, RPE is your own perception... it could easily be misperceived. The Lt test you did was it based on CO2, or actual blood work? If it was based on CO2 you could be well adapted to oxygen consumption, work well with limited oxygen, but that doesn't mean you're in oxygen dept which implies you're not at your LT.

If the test was based on blood work, then... i really don't know what to say, maybe you can explain that.

The first lactate threshold was estimated based on the respiratory exchange ratio, which is an estimation of substrate usage based on the ratio of VCO2/VO2. At 0.7 the primary substrate is fat and at 1.0 the primary substrate is carbohydrate. Therefore, an RER of 1.0 is the lactate threshold because it is where the body is burning primarily carbohydrate for the exercise and carbohydrate is the only substrate that can be burned anaerobically. It's not necessarily the amount of oxygen that you have (IE: ability to breathe) but the amount of oxygen that the cells are using (VO2) for substrate conversion to ATP. At the beginning of cardiovascular exercise, the body switches over from primarily fatty acid oxidation to primarily anaerobic glycolysis (The first Lactate Threshold) because the increased intensity will require faster ATP production then waiting on the Kreb's cycle. With adequate warm-up prior to the high intensity exercise, the body will not have a lack of ability to breathe, but the muscle cells won't be using the oxygen because of working anaerobically. After a while then it will switch again, backing down the anaerobic glycolysis and ramping up the fatty acid oxidation, which is when the Kreb's cycle plays a bigger part. Because this was a maximum effort test, the Kreb's cycle doesn't come into play because the intensity is too high and the duration too short.

... I do have to wash my Polar chest strap after every 5 uses because the salt in it from sweating throws off the readings.

The instructions on my Polar say to rinse the band after every use and to remove the transmitter because the presence of moisture causes it to run down.

Not wishing to shove the broscience aside too heavily in favour of, you know, actual science, but.... :-)

There's at least some evidence that the rosuvastatin you're taking has a depressing effect on HR, and it certainly impacts on BP. Apart from being used to reduce cholestrol, it's also used to prevent heart attacks and strokes in people at risk. You might want to get some proper advice from the prescribing medical practitioner on the impact these meds might have on your exercise, particularly on your heart rate. For people who are taking, for instance, beta blockers and similar meds, it's likely that HRMs aren't a good measure of calorie burn at all, and that you're better off relying on things like distance travelled and estimates based on effort.

I found that when I was on beta blockers, it was hell getting my heart rate over 125-130. I suspect you might be having the same issues.

I hope that's genuinely helpful.

Yeah, right. Don't bother with the doctor. Listen to Pu.... It's very, very important that he be right.