Crazy calorie burns for P90X? Can this be right?

NateDad

I've been using my HRM during P90X for a couple weeks now, and from what I've read on here, I'm burning a lot more calories than average.... or my HRM is reporting high. I have a brand new Polar FT4. I'm 6'1", 174 pounds, 34 years old, and before P90X I was nearly completely sedentary... my exercise mainly consisted of carrying around a 20 pound baby, and a 0.7 mile walk between the train station and work (desk job).

For example, last night I did legs and back and ab ripper X, and my HRM said 1085 calories burnt. My average heart rate was 137, max was 173, and time in zone 1:06:03. I push pretty hard in these exercises, and the pull ups always get my heart rate up there (I'm sure that's where I hit 173).

But... really, 1085?

For comparison, doing C25K Week 2 Run 1 the other day (walking @4mph, running @6mph, 1% grade on the treadmill), I burned 385 calories in 30 minutes, according to my HRM. (average HR 137, max 165, Time in zone: 18:23)

Does this sound right to anyone else?

-Nate

neverstray

No. P90X, in their own literature, mainly in the nutrition information, they discuss that on average, you will burn 600 calories on each exercise. However, it varies quite a bit. The Plyo and Kenpo and the biggest burners I think with most people reporting numbers around 600 - 800 calories. Some of the other exercises burn more around 300 - 400.

Have you tested your HRM to make sure it's accurate?

Then again, maybe you're just a baddass.

Cwilliams8676

Maybe turbo jam says it burs 1000 per hr

NateDad

Last time I did Plyometrics it was 820, Kenpo X 720. Badass, or badly out of shape?

GonnaBeAFitMom

Last time I did Plyometrics it was 820, Kenpo X 720. Badass, or badly out of shape?

Can't it be both?

aweightymatter

IMHO that sounds a bit high... I'm decently in shape but not super woman or anything, and on average for legs and back I got a burn according to my HRM of around 400 or 500 an hour. I'm 5'6" and fairly sturdy -- can't tell from your pic but I doubt I'm "tiny" or anything compared to you.

As the program progressed and I got in better shape, the burns decreased even more -- by the end I was only rating like 275 per hour for things like shoulders and arms. I never bothered with Kenpo (ran instead), but I always got the highest burns from the Plyo video, but again, those were similar to a running session over the same time period -- maybe 600 or 700 calories, nothing too outlandish.

I found the program helpful to get back into strength work though and to get a bit of a cutting effect. It's definitely great and you should stick with it -- just maybe don't eat back all the calories your HRM says you burned.

dadoffo

Last time I did Plyometrics it was 820, Kenpo X 720. Badass, or badly out of shape?

The Kempo was kinda high. Last time I did Plyo it was 701 and for Kempo 490.

kendra0224

I just got an FT4 and have had no issues with it calculating calories incorrectly. If you want to check the calories burned you can go to this link http://www.braydenwm.com/calburn.htm and put the info in. It is what I did when I was using a pyle HRM that calculated way off. Doing P90X for an hour is a lot of work, so I would say that it is more than likely correct. That is an awesome burn though!

erickirb

HRM's are not accurate for calories burned for any activity other than cardio. This is because the calculation embedded in the watch assumes a certain oxygen uptake and bases intensity on your HR, to see where you are relative to your max oxygen uptake (V02Max). But the reason your HR elevates due to strength training is different then that of cardio which makes that portion of the equation wrong, typically will over shoot your actual burn).

It may be a little more accurate if you pause between sets for the duration you are not actually doing any exercise, but even then it may be way off.

bobbybdoe

Plyometrics burns the most out of all the DVDs, but all the DVDs have a generally high calorie burn. I'm usually anywhere from 300-800 whenever I do P90X and the same goes for when I'm doing Insanity.

kendra0224

IMHO that sounds a bit high... I'm decently in shape but not super woman or anything, and on average for legs and back I got a burn according to my HRM of around 400 or 500 an hour. I'm smaller than you naturally but not tiny or anything

As the program progressed and I got in better shape, the burns decreased even more -- by the end I was only rating like 275 per hour for things like shoulders and arms.

I found the program helpful to get back into strength work though and to get a bit of a cutting effect. It's definitely great and you should stick with it -- just maybe don't eat back all the calories your HRM says you burned.

I agree. Leave a pretty large deficit to make room for error.

erickirb

Last time I did Plyometrics it was 820, Kenpo X 720. Badass, or badly out of shape?

There is no way you would have burned more then during Plyo,

dcgonz

Last time I did Plyometrics it was 820, Kenpo X 720. Badass, or badly out of shape?

This looks about right for these two workouts. To me your strength work out was a little high, to burn over 1000 calories you must have been really working those pull-ups! :laugh:
If you are out of shape, you will burn more calories because you are working harder. As you progress through the progam building your endurance & strength you will see your calorie burn decrease

Diana

ladybug1620

It does sound high, but it makes sense. You spent over an hour in your fat burning zone with the P90X and only 18 minutes in the zone with C25K, meaning you would burn way more calories doing an hour of P90X than an hour of C25K. If you do the math it pretty much evens out. Great job

aweightymatter

HRM's are not accurate for calories burned for any activity other than cardio. This is because the calculation embedded in the watch assumes a certain oxygen uptake and bases intensity on your HR, to see where you are relative to your max oxygen uptake (V02Max). But the reason your HR elevates due to strength training is different then that of cardio which makes that portion of the equation wrong, typically will over shoot your actual burn).

It may be a little more accurate if you pause between sets for the duration you are not actually doing any exercise, but even then it may be way off.

This is interesting, and from what I've read, true... I wonder how that relates to a program like P90x though which is somewhere in the middle. It's not your typical strength training where you do slow or steady reps -- but it's not exactly cardio where you're flailing around.

dcgonz

HRM's are not accurate for calories burned for any activity other than cardio. This is because the calculation embedded in the watch assumes a certain oxygen uptake and bases intensity on your HR, to see where you are relative to your max oxygen uptake (V02Max). But the reason your HR elevates due to strength training is different then that of cardio which makes that portion of the equation wrong, typically will over shoot your actual burn).

It may be a little more accurate if you pause between sets for the duration you are not actually doing any exercise, but even then it may be way off.

Very interesting! I did not know that, thanks for the info!

Diana

erickirb

HRM's are not accurate for calories burned for any activity other than cardio. This is because the calculation embedded in the watch assumes a certain oxygen uptake and bases intensity on your HR, to see where you are relative to your max oxygen uptake (V02Max). But the reason your HR elevates due to strength training is different then that of cardio which makes that portion of the equation wrong, typically will over shoot your actual burn).

It may be a little more accurate if you pause between sets for the duration you are not actually doing any exercise, but even then it may be way off.

This is interesting, and from what I've read, true... I wonder how that relates to a program like P90x though which is somewhere in the middle. It's not your typical strength training where you do slow or steady reps -- but it's not exactly cardio where you're flailing around.

It would still be off, but closer then traditional strength training. When doing pull-up and the like your HR spikes for a completely different reasons then with cardio, so it would still be off.

fasttrack27

sounds high to me. I'm not too far from your age/weight, but have been working out a little longer. I have a Polar FT40. When my average HR is in the 130's like that, I'd show maybe half that amount of calories burned. I get to that 1000/hr range when I average 160bmp with a long hard run. At least for me, the 130'ish average is a nice midpoint workout. Feels like I'm working but not too crazy hard. Once I get to 150 and up, the effort and calorie burn really seems to jump way high. But thats just me....

jram70

The highest I saw on P90X with my heart monitor was on Legs & Back Day about the 2nd or 3rd week in and I burned 985. I was really busting it so I say it is possible. What I did is went with what my monitor said, even if it was low, that way I am consistent in recording and any overs/unders should balance out.

alj322003

doing the math while running you burned around 12 calories per minute doing px90 you burned around 16 per minute heart rate was higher during px90 so sound reasonable to me

gafrausto

FT4 may just be defective or needs to be reset...not sure if resetting is possible on all HRMs.

rides4sanity

My hr and cal burns are always higher than I think they should be. For instance I can teach a spin class and talk the whole time with an average hr in the 160's max'ing in the 190's. According to the charts this shouldn't happen in your late 30's, but it does and I'm perfectly fine. Because the calorie burn is based primarily on hr, I feel is not completely accurate for me. Because of this I tend to only eat back about 60% of the calories I record. Heart rates and such are based on an average, and its possible you are just a bit outside of that. You can easily verify your HR monitor by doing a 15 second pulse count and multiplying by 4, if the monitor is good but you are higher than you think you should be talk with your doc just to make sure things are good. Otherwise keep on busting out the workouts, good luck!

heybales

I've been using my HRM during P90X for a couple weeks now, and from what I've read on here, I'm burning a lot more calories than average.... or my HRM is reporting high. I have a brand new Polar FT4. I'm 6'1", 174 pounds, 34 years old, and before P90X I was nearly completely sedentary... my exercise mainly consisted of carrying around a 20 pound baby, and a 0.7 mile walk between the train station and work (desk job).

For example, last night I did legs and back and ab ripper X, and my HRM said 1085 calories burnt. My average heart rate was 137, max was 173, and time in zone 1:06:03. I push pretty hard in these exercises, and the pull ups always get my heart rate up there (I'm sure that's where I hit 173).

But... really, 1085?

For comparison, doing C25K Week 2 Run 1 the other day (walking @4mph, running @6mph, 1% grade on the treadmill), I burned 385 calories in 30 minutes, according to my HRM. (average HR 137, max 165, Time in zone: 18:23)

Does this sound right to anyone else?

The HRM calorie calc's are only accurate for aerobic type activities - a lot of that is like weight lifting - anaerobic.

So while the HR is getting up there because of the effort involved, it is anaerobic and therefore very inaccurate estimates.
Because it thinks you are hitting those highs aerobically, which would be massive burn then.

That being said for calorie burn estimate during the workout - if you include the fact anaerobic burns much more after the workout for hours with increased metabolism and repair/recovery of muscles - in total, that is probably closer to the truth.

If you are wanting to know in an effort to feed your workout correctly so you'll benefit from it fully, I'd say go for P90X estimate of burn, because you'll soon reach that as you get more aerobically fit, and if you start seeing difficulty with workout, like your body is just not recovering enough, then eat them all back.

KissesHugs2

I am interested to know the same thing. I also do P90X sometimes and also Zumba. I purchase a Sportline SX HRM a few weeks ago and it told me that I burned 835 calories for an hour and 15 minutes of Zumba. My maximum heart rate was 206. It was a hard workout but I am not sure what to compare these numbers too ???

heybales

I am interested to know the same thing. I also do P90X sometimes and also Zumba. I purchase a Sportline SX HRM a few weeks ago and it told me that I burned 835 calories for an hour and 15 minutes of Zumba. My maximum heart rate was 206. It was a hard workout but I am not sure what to compare these numbers too ???

It's really not a matter of what your max was, because that could have been reached 1 time for 2 seconds, and your avg was actually 120.

That's what is closer to fact, your AHR.

And there are a bunch of responses in this thread mentioning what you can compare it to or the recommendation - not sure if you read them or not.

heybales

My hr and cal burns are always higher than I think they should be. For instance I can teach a spin class and talk the whole time with an average hr in the 160's max'ing in the 190's. According to the charts this shouldn't happen in your late 30's, but it does and I'm perfectly fine. Because the calorie burn is based primarily on hr, I feel is not completely accurate for me. Because of this I tend to only eat back about 60% of the calories I record. Heart rates and such are based on an average, and its possible you are just a bit outside of that. You can easily verify your HR monitor by doing a 15 second pulse count and multiplying by 4, if the monitor is good but you are higher than you think you should be talk with your doc just to make sure things are good. Otherwise keep on busting out the workouts, good luck!

Sadly the HRM setup and default values for women make it more of a chance for inaccuracy. Men luck out.

Women are also more likely to slow their metabolism down by underfeeding too far compared to men, and a slower metabolism also burns less calories than even the correct stats would indicate.

http://www.myfitnesspal.com/topics/show/459580-polar-hrm-calorie-burn-estimate-accuracy-study

Depending on the values you can manually adjust, probably at least MHR, perhaps VO2max also, you can correct it if you test for those values.
http://www.myfitnesspal.com/topics/show/466973-i-want-to-test-for-my-max-heart-rate-vo2-max

dreweth

I've been using my HRM during P90X for a couple weeks now, and from what I've read on here, I'm burning a lot more calories than average.... or my HRM is reporting high. I have a brand new Polar FT4. I'm 6'1", 174 pounds, 34 years old, and before P90X I was nearly completely sedentary... my exercise mainly consisted of carrying around a 20 pound baby, and a 0.7 mile walk between the train station and work (desk job).

For example, last night I did legs and back and ab ripper X, and my HRM said 1085 calories burnt. My average heart rate was 137, max was 173, and time in zone 1:06:03. I push pretty hard in these exercises, and the pull ups always get my heart rate up there (I'm sure that's where I hit 173).

But... really, 1085?

For comparison, doing C25K Week 2 Run 1 the other day (walking @4mph, running @6mph, 1% grade on the treadmill), I burned 385 calories in 30 minutes, according to my HRM. (average HR 137, max 165, Time in zone: 18:23)

Does this sound right to anyone else?

-Nate

Sounds right to me, if you are really "bringing it" during Legs and Back. My HRM says I have burned even more than that during that workout, though I have more weight to lose and am more out of shape than you may be.

Anyone that is saying "no, too high" may be jealous, but running (unless extreme HIIT) is not as hard as Legs and Back at full intensity. That is a monster burn, cardio and resistance workout, and one of the hardest of P90X for me, harder than plyo.

That said, I still don't eat all of those calories back, typically on big days like that. I usually subtract a few hundred calories because I don't feel like eat all of it back.

Lastly, do the math. You said ~385 calories with an in-zone time of 18 minutes, around 21 calories per minute of in-zone time. Your P90X workout was 61 minutes of in-zone time, which is only 18 calories per minute. How does that not make sense if you have the same average heart rate for in-zone time?

aweightymatter

I've been using my HRM during P90X for a couple weeks now, and from what I've read on here, I'm burning a lot more calories than average.... or my HRM is reporting high. I have a brand new Polar FT4. I'm 6'1", 174 pounds, 34 years old, and before P90X I was nearly completely sedentary... my exercise mainly consisted of carrying around a 20 pound baby, and a 0.7 mile walk between the train station and work (desk job).

For example, last night I did legs and back and ab ripper X, and my HRM said 1085 calories burnt. My average heart rate was 137, max was 173, and time in zone 1:06:03. I push pretty hard in these exercises, and the pull ups always get my heart rate up there (I'm sure that's where I hit 173).

But... really, 1085?

For comparison, doing C25K Week 2 Run 1 the other day (walking @4mph, running @6mph, 1% grade on the treadmill), I burned 385 calories in 30 minutes, according to my HRM. (average HR 137, max 165, Time in zone: 18:23)

Does this sound right to anyone else?

-Nate

Sounds right to me, if you are really "bringing it" during Legs and Back. My HRM says I have burned even more than that during that workout, though I have more weight to lose and am more out of shape than you may be.

Anyone that is saying "no, too high" may be jealous, but running (unless extreme HIIT) is not as hard as Legs and Back at full intensity. That is a monster burn, cardio and resistance workout, and one of the hardest of P90X for me, harder than plyo.

That said, I still don't eat all of those calories back, typically on big days like that. I usually subtract a few hundred calories because I don't feel like eat all of it back.

Lastly, do the math. You said ~385 calories with an in-zone time of 18 minutes, around 21 calories per minute of in-zone time. Your P90X workout was 61 minutes of in-zone time, which is only 18 calories per minute. How does that not make sense if you have the same average heart rate for in-zone time?

I can assure you I'm not jealous I still think it's better to err on the side of NOT eating back all those calories when you get a really high burn calculation, since we can never really get an accurate count of either calories burned or, really, eaten.