Running avg HR too high according to Polar = no fat lost?

cummingscb

So, in a former life (20+ years ago), I was a varsity track and cross country runner - although I was never really built like one (stereotypically for distance runners, they were always long and lean, whereas I was shorter and more muscular - at my peak, when my mile splits were about 6 minutes per mile, I was 5 ft, 5 inches, and 135 pounds). It was the only "sport" that I excelled in. I wasn't "elite" enough to continue running competitively in college, so I eventually just stopped running. Then stopped exercising. Then started gaining weight, got married, had babies, gained more weight. I finally decided enough was enough around 235 lbs. I started exercising again and watching what I ate, thanks to MFP, and I've gotten down to 181, so over 50 lbs lost. I have done enough cardio and strength training over the last 6 months, that I decided to make my next challenge to start running again, and gave myself a goal of running a half marathon in February. So, I've been running for 7 weeks now. My pace is much faster than I expected it to be (I average a 10 minute mile), but I am not overexerting, in my opinion, because I am able to catch my breath after just a couple of minutes of being done, and I don't have any muscle soreness the next day.

For Christmas, I got a Polar FT4 monitor, because I've noticed that I've sort of stopped losing weight. Despite still exercising almost daily....despite watching my calories (I average around 1500), so I wanted to more accurately monitor my calorie burn. I have noticed, since wearing the Polar, that for nearly every run, which goes between about 30 minutes for 3 miles to 71 minutes for 7 miles, I'm only staying in my "target heartrate range" for 2-3 minutes TOTAL. I was floored. And thinking that I wasn't working hard enough, even though I certainly felt like I was. Then my husband did a little further inspection, and the epiphany hit us that the reason I wasn't in the "target range" was because my average heart rate, when running, is really ABOVE the "target range". The range the Polar has set for me is between 119-157 bpm. My average is 166bpm. And my max is registering about 184 bpm. So, apparently, I'm doing more than enough - in fact, too much. Here's my dilemma. It doesn't feel like I'm doing too much. It FEELS like I'm exercising just right - pushing myself, but not so hard that I'm feeling repercussions during or after the run. But could this explain why I'm not losing any more weight? The whole goal of starting running was to do something different in this next phase of weight loss. I'm still easily 30-40 lbs from where I'd like to be. 181 is not probably an awesome weight for a short-ish person like me to be pounding the pavement with. I don't want to hurt myself and jeopardize the hard work that I HAVE accomplished, although my knees have held up pretty well - no need yet for any braces, wraps, etc. Should I be slowing it down to maybe a 12 minute mile, so that I'm staying in that target heart rate range? Is that why I'm not losing weight, because I'm going so hard that I'm not burning fat, but rather sugar instead, and muscles are breaking down? I could use some educated advice on this, because the internet tells me about 360 degrees of information about this, so I don't know what's true and what's not. Just keep in mind that I am still technically classified as "obese" as BMIs go, but definitely have the athletic build of short and compact, and that my end goal is really to be lighter (while getting more heart-healthy in the process).

hilts1969

If you are running between 30 mins and 71 mins you will be burning plenty of calories, wouldn't worry about getting your heart rate in a certain range, for a start this range is a general guide you may have a slightly higher heart rate, with regards to not losing weight as fast as previously this happens to most people

I lost 10llbs first month 6 the next 2 after then 8 after that and my calorie intake and exercise length was pretty much the same

Try not to think too much, exercise and eat right and you will be fine

As you get lighter and fitter you will naturally lose less weight anyhow

acpgee

I manually changed my max heart rate in the settings of my Polar FT4, because I got annoyed with it beeping when my heart rate was too high. This might have implications for the calorie burn estimate though. I figure no harm done, as I am in pretty good cardio nick for my age.

Mr_Knight

As long as you are meeting the biomechanical definition of running, you will burn the calories, regardless of which heart rate zone you're in.

net burn calories running = 0.63 * miles run * body weight in pounds

Can you give an example of distance/burn produced by your HRM? Are you eating back running calories?

Alexandria1213

You could always run slower, but maybe put your incline higher? that way you can slow down comfortably but still working a sweat

FrauMama

I am the same way; if I went for what Polar said my "fat burning" HR was, I'd not even break a sweat. My workouts average around 160-175 HR, up to 180, and almost never lower than about 150. (That is working hard; plyometrics, HIIT, stair-running etc).

As long as you don't have any heart or other health issues, just change your settings on Polar. The "fat burning" zone is fairly obsolete...you are still burning more fat burning more calories TOTAL. Go for the higher heart rate (within relative comfort) and don't worry about what Polar recommends.

JohnDowding

Sounds like me too. To be on the safe side, talk to your doctor, and maybe get a stress test, but an average is just that, lots of people will be above it.

FrauMama

It doesn't feel like I'm doing too much. It FEELS like I'm exercising just right - pushing myself, but not so hard that I'm feeling repercussions during or after the run. But could this explain why I'm not losing any more weight?

I think this is key...your workouts sound great. You are definitely not "working too hard" to lose weight. I would not lessen intensity, though you may want to consider using some HIIT principles and, say, running HARD for 30 seconds and then more mellow for 1 or 2 minutes, etc, if you are at a weight loss plateau. Again, UNLESS you have any health issues, don't lessen intensity; those recommended HRs are sort of arbitrary and pretty old-school. They are very, VERY safe numbers that don't necessarily work well in the real world.

cummingscb

As long as you are meeting the biomechanical definition of running, you will burn the calories, regardless of which heart rate zone you're in.

net burn calories running = 0.63 * miles run * body weight in pounds

Can you give an example of distance/burn produced by your HRM? Are you eating back running calories?

Yes, for instance, yesterday, I ran 2.88 miles. It took 27 minutes (so just under 10 minutes per mile) and calories burned registered at 316. That seems right for me. The calorie burn seems pretty accurate, but there's nothing happening on the scales or with measurements either. So that's when I thought that maybe I was overexerting, based on the average heart rate being above where Polar was saying it needed to be, and maybe that was why I wasn't getting anywhere with the weight loss. I've lost 2 lbs in the last 5 weeks (granted one of those weeks I was on vacation/Christmas), but with the running 7 weeks in, I expected that I would have burned enough calories to make up for any dietary indiscretions (which are few these days).

bushidoxsh

To the OP, your current situation is nearly identical to mine in workouts, including weight. The big difference is that I am male and 6", ran two years in HS and 2 years in college, and I am now 36. I have started back working out, including running since September and was 235 lbs when I started. Having done a fair bit of research to determine where I should be in workouts, I have found a ton of varying information. I then talked to two separate physical therapists (yea for having relatives in medicine) and got their opinion. They said that the target heart rate is just that, a target, and a goal to go by for what is considered medium exercise. Vigorous exercise will obviously put you above that as well. They said that for an overweight to obese person, aka a BMI of 22 to 35% that your heart rate should never exceed 300% of your at rest heart rate. My typical heart rate at rest is about 68, so I would be fine up to 200 BPM, and when running for 35 to 40 minutes I hit about 185. While high, it is not dangerous. In your case, I would assume you are hitting the 170 to 180 range regularly, and as long as your resting heart rate is above 63 or so you should be fine. acpgee has a great suggestion, that should help with the Polar.

As far as your concerns about your workout, my personal evidence suggests that as long as you follow the basics of weight loss you should be fine. Those obviously include regular exercise 3+ workouts a week at a medium rate for 30+ minutes at a time, cutting out empty calories (limiting alcohol, limiting soda etc), avoiding really bad for you foods (typical fast food fare), staying hydrated, and in general finding ways to stay less sedentary. This typically will result in .5 to 1.5 pounds of weight loss a week, more if you exercise and watch your diet better, less if you don't. For running, especially when you hit 35 years or more in age, your body handles weight loss differently. Running will first build your stamina and endurance, and that includes building muscle and some body changes. It is only after your body adjusts to the exercise that you will begin to see weight loss. I personally found it very frustrating that I could run 3.5 miles in 35 minutes and see little to no weight loss, but get a much bigger result form 32 minutes on an elliptical and burning, according to the machine, 420 calories. It took me a full 12 weeks before the running saw real weight loss associated with it. Your body type, being more stocky, than say a gazelle like runner, will in general, just be harder to keep burning weight. Our body types are similar, so I feel the frustration, we have a bigger hill to initially climb to see results.

Everything that you posted seems to be a great step in the right direction. Do not let the fact that you are not losing weight quickly, or as fast as you'd like discourage you, being able to run for an hour at a time makes me envious. The most important thing you can do is be honest about how the exercise is acting on your body. If you feel comfortable while working out at your level, are not having nagging injuries or pains, especially in the joints/back, and feel better for exercising then you are doing it right. Keep up what you are doing, and remember that muscle is a lot denser than fat, and your body will take time to change. Good luck.

snowmaniac

You may want to try upping your calorie intake. Based on the information you provided, using one of the popular TDEE calculators you should be netting around 1800 if you sedentary. You said you are averaging around 1500 calories. Is that net or gross?

cummingscb

You may want to try upping your calorie intake. Based on the information you provided, using one of the popular TDEE calculators you should be netting around 1800 if you sedentary. You said you are averaging around 1500 calories. Is that net or gross?

That's a good question. My 1500 is gross, which I know means that I'm probably not eating enough calories, considering I burn 300-600, depending on how long I run (and I run about 4-5 days a week since I'm training for a half marathon). Before I started running, and was still exercising in the gym with group exercise classes or elliptical/stairmaster workouts, I did experiment with adding more calories (quality calories, like baked potato with cheese or chicken with pasta), but found that I gained weight on the weeks where I experimented with that. So, I decided that it must be one of the dietary suggestions that doesn't work for my metabolism/body type, etc. MFP suggests I net 1200 calories per day in order to lose 1.5 lbs per week, so I'm close to that with my workouts, but still a little under on certain days. Since I'm running now, I might think about trying to add some extra calories back in, to see if that makes a difference.