HELP! How do I log this?!

JenMarie8781
JenMarie8781 Posts: 377 Member
in Fitness and Exercise
I just started taking a water aerobics class. Today was my second class. I use a Polar FT4 HRM and I read online that the transmitter wouldn't work underwater. Well, I decided to test it out and mine did work... I didn't get the "Error" message like other people had said they got. BUT.... I'm almost positive it is not giving me an ACCURATE reading. I was getting pretty winded and I felt like I was working hard yet my HRM never went above 115. Then today, I noticed that before I got into the pool it was reading 118 and then AS SOON as I got into the water, it went down to 103. So I don't think it is reading accurately while I'm in the pool.

So now I have no idea how to log my exercise for the Water Aerobics class. Today I did 47 minutes and my HRM says I burned 210 calories but I know that isn't right... it's too low. BUT then if I go by the MFP calculations for "Water Aerobics, Water Calesthenics" and put in 47 minutes it says I burned 430 calories which is double what my HRM says and I'm pretty sure that is too HIGH.

So how the heck do I know how many calories I'm burning?!!! Grrr!

Replies

  • JenMarie8781
    JenMarie8781 Posts: 377 Member
    Anyone....?
  • JenMc14
    JenMc14 Posts: 2,389 Member
    Honestly, I'd take an average of the two, 320, and round down to 300. I wouldn't eat back anymore than 200 unless I was netting below 1200.
  • trogalicious
    trogalicious Posts: 4,584 Member
    Both are gonna be an estimate, but I'd trust the HRM more than the website/app. At least the HRM is set for you. Maybe you've been overestimating how much you've burned for a while anyway.
  • srslybritt
    srslybritt Posts: 1,618 Member
    Just remember that no matter how "high-tech" something is, it's still just an estimate for calories burned. There is almost no way to know "exactly" how many calories we burn. I would say taking an average and rounding up/down to the nearest 50 would be about right. When it comes to my exercise log, I log it with MFP's figures and eat back about 35% of the calories it tells me I burned, unless I'm netting higher than 1200. Good luck! :)
  • CeCe_711
    CeCe_711 Posts: 35
    when my HRM was on the fritz I would stop every 10/15 min and take my heart rate for 10 seconds. after my workout i'd take the average of those numbers to find average heart rate per minute and then i'd stick it into this online calculator... it's not the most efficient or effective but for me it was better than nothing. ---> http://www.shapesense.com/fitness-exercise/calculators/heart-rate-based-calorie-burn-calculator.aspx
  • ze_hombre
    ze_hombre Posts: 377 Member
    I just started taking a water aerobics class. Today was my second class. I use a Polar FT4 HRM and I read online that the transmitter wouldn't work underwater. Well, I decided to test it out and mine did work... I didn't get the "Error" message like other people had said they got. BUT.... I'm almost positive it is not giving me an ACCURATE reading. I was getting pretty winded and I felt like I was working hard yet my HRM never went above 115. Then today, I noticed that before I got into the pool it was reading 118 and then AS SOON as I got into the water, it went down to 103. So I don't think it is reading accurately while I'm in the pool.

    So now I have no idea how to log my exercise for the Water Aerobics class. Today I did 47 minutes and my HRM says I burned 210 calories but I know that isn't right... it's too low. BUT then if I go by the MFP calculations for "Water Aerobics, Water Calesthenics" and put in 47 minutes it says I burned 430 calories which is double what my HRM says and I'm pretty sure that is too HIGH.

    So how the heck do I know how many calories I'm burning?!!! Grrr!

    The reason the HRM isn't recording properly is because Bluetooth does not transmit well in water. You can get some of it through shallow water, but not more than a few inches below water. That is why you are not seeing consistent measurement and why it dropped as soon as you got in. Some of the signal is getting through, but not all of it. HRMs work by transmitting a radio frequency pulse each time a heart beat is detected. Radio does not transmit through water effectively.
  • ze_hombre
    ze_hombre Posts: 377 Member
    I just started taking a water aerobics class. Today was my second class. I use a Polar FT4 HRM and I read online that the transmitter wouldn't work underwater. Well, I decided to test it out and mine did work... I didn't get the "Error" message like other people had said they got. BUT.... I'm almost positive it is not giving me an ACCURATE reading. I was getting pretty winded and I felt like I was working hard yet my HRM never went above 115. Then today, I noticed that before I got into the pool it was reading 118 and then AS SOON as I got into the water, it went down to 103. So I don't think it is reading accurately while I'm in the pool.

    So now I have no idea how to log my exercise for the Water Aerobics class. Today I did 47 minutes and my HRM says I burned 210 calories but I know that isn't right... it's too low. BUT then if I go by the MFP calculations for "Water Aerobics, Water Calesthenics" and put in 47 minutes it says I burned 430 calories which is double what my HRM says and I'm pretty sure that is too HIGH.

    So how the heck do I know how many calories I'm burning?!!! Grrr!

    The reason the HRM isn't recording properly is because Bluetooth does not transmit well in water. You can get some of it through shallow water, but not more than a few inches below water. That is why you are not seeing consistent measurement and why it dropped as soon as you got in. Some of the signal is getting through, but not all of it. HRMs work by transmitting a radio frequency pulse each time a heart beat is detected. Radio does not transmit through water effectively.

    PS - this is going to be the case for all HRM's, even the ones that are designed for triathlon runners. The transmitters (the part that goes on the chest strap) will read the heart rate fine and they are all water proof (or at least resistant to 1 atmosphere), but getting the data to the phone will require either a wire or a different means of transmitting the data (I know of no radio frequency that works in water so that eliminates ANT+, Bluetooth, and BLE (the only wireless frequencies I know of in use today).
  • JenMarie8781
    JenMarie8781 Posts: 377 Member
    I just started taking a water aerobics class. Today was my second class. I use a Polar FT4 HRM and I read online that the transmitter wouldn't work underwater. Well, I decided to test it out and mine did work... I didn't get the "Error" message like other people had said they got. BUT.... I'm almost positive it is not giving me an ACCURATE reading. I was getting pretty winded and I felt like I was working hard yet my HRM never went above 115. Then today, I noticed that before I got into the pool it was reading 118 and then AS SOON as I got into the water, it went down to 103. So I don't think it is reading accurately while I'm in the pool.

    So now I have no idea how to log my exercise for the Water Aerobics class. Today I did 47 minutes and my HRM says I burned 210 calories but I know that isn't right... it's too low. BUT then if I go by the MFP calculations for "Water Aerobics, Water Calesthenics" and put in 47 minutes it says I burned 430 calories which is double what my HRM says and I'm pretty sure that is too HIGH.

    So how the heck do I know how many calories I'm burning?!!! Grrr!

    The reason the HRM isn't recording properly is because Bluetooth does not transmit well in water. You can get some of it through shallow water, but not more than a few inches below water. That is why you are not seeing consistent measurement and why it dropped as soon as you got in. Some of the signal is getting through, but not all of it. HRMs work by transmitting a radio frequency pulse each time a heart beat is detected. Radio does not transmit through water effectively.

    Well that sucks. Why is it waterproof if it doesn't actually WORK in the water? lol
  • ze_hombre
    ze_hombre Posts: 377 Member
    I just started taking a water aerobics class. Today was my second class. I use a Polar FT4 HRM and I read online that the transmitter wouldn't work underwater. Well, I decided to test it out and mine did work... I didn't get the "Error" message like other people had said they got. BUT.... I'm almost positive it is not giving me an ACCURATE reading. I was getting pretty winded and I felt like I was working hard yet my HRM never went above 115. Then today, I noticed that before I got into the pool it was reading 118 and then AS SOON as I got into the water, it went down to 103. So I don't think it is reading accurately while I'm in the pool.

    So now I have no idea how to log my exercise for the Water Aerobics class. Today I did 47 minutes and my HRM says I burned 210 calories but I know that isn't right... it's too low. BUT then if I go by the MFP calculations for "Water Aerobics, Water Calesthenics" and put in 47 minutes it says I burned 430 calories which is double what my HRM says and I'm pretty sure that is too HIGH.

    So how the heck do I know how many calories I'm burning?!!! Grrr!

    The reason the HRM isn't recording properly is because Bluetooth does not transmit well in water. You can get some of it through shallow water, but not more than a few inches below water. That is why you are not seeing consistent measurement and why it dropped as soon as you got in. Some of the signal is getting through, but not all of it. HRMs work by transmitting a radio frequency pulse each time a heart beat is detected. Radio does not transmit through water effectively.

    Well that sucks. Why is it waterproof if it doesn't actually WORK in the water? lol

    Mainly because people tend to sweat a lot when wearing them. :)

    This is why submarines do not use RADAR and use SONAR instead. Water is a horrible transmitter of all electromagnetic frequencies, but its an excellent conductor of sounds. Sadly, I know of no HRM's that transmit by SONAR, though, but if any Polar or Zephyr reps stop by this thread <hint> <hint>.

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