Does swimming really burn that many calories?

Most sites say that you burn a lot more calories swimming than you do walking or running, or really more than most any other exercise. So when I put in that I swam for two hours, even on light/moderate effort, it gave me 1200 calories burned. By contrast, if I'd walked at 3.5mph for two hours, I'd have only burned 600+ calories. I understand that it is the effort of going through the water, full body workout, etc.

But here's the question... if my heart rate is lower swimming for two hours than it is if I spent 2 hours walking on the treadmill (I'm a good swimmer, so this is the case for me), wouldn't it make sense given a lower heart rate that I burned fewer calories than my treadmill workout?

Replies

  • AliciaNorris81
    AliciaNorris81 Posts: 185 Member
    I was discussing this with my physical therapist once. I told him I went swimming for a couple of hours and burned a bunch of calories. He asked if I was casually swimming (like with family or kids) or was I actually SWIMMING the whole time? Two totally different things.

    IF you are actually swimming, yes it will burn a ton of calories. You have to think, you aren't just floating there. You are in a constant state of tension to keep your body above that water and moving. I don't think it burns as much as MFP says (I usually put in 3/4 the time) but I do know it burns a lot.
  • I am a swimmer from my high school days. When I go swimming, my heart rate gets up there, and I actually sweat while in the pool. If you aren't swimming that hard, then I don't think that you burn that many calories. You do need to consider that you are using all your muscles; legs, arms, core. It is a great calorie burner if you swim constantly at a decent pace.
  • No, I swim. Not play around with the kids, but actually swim. And usually at a pretty good clip. I sweat too. But my HR isn't any different than it is working hard (for me) on a treadmill. So I'd think that based on HR, the two would burn the same amount of calories. But that's never what comes up when you plug it in online.
  • concordancia
    concordancia Posts: 5,320 Member
    HRM s are not accurate for water exercise. Your heart works differently when it doesn't have to contend with so much gravity. If you were actually swimming, I am sure you got a good burn. If you were goofing off in the pool, you probably got an ok burn. If you were sunning in the lounger beside the pool, you may have gotten skin cancer.
  • DPernet
    DPernet Posts: 481 Member
    I swim about 3km per day, 5 days a week. It takes me an hour to swim the 3k. I just enter it as 'Swimming, Leisurely, General' to be on the safe side. Seems to be working for me that way :smile:
  • 3dogsrunning
    3dogsrunning Posts: 27,167 Member
    Heart rate does not affect calories burned. There is a relationship between VO2 and heartrate during moderate intensity exercise that allows for an estimation of calories burned. So I would not discount it based on HR alone.

    As for the question about swimming, I am pretty skeptical myself. I usually log at the lowest insanity and under estimate my time.
  • But doesn't your heart rate give you some idea of how many calories you burn? Why else would all kinds of people be using their HR monitors to help them determine calories burned?
  • Heart rate does not affect calories burned. There is a relationship between VO2 and heartrate during moderate intensity exercise that allows for an estimation of calories burned. So I would not discount it based on HR alone.

    As for the question about swimming, I am pretty skeptical myself. I usually log at the lowest insanity and under estimate my time.

    You say heart rate doesn't affect calories burned and then say that there is a relationship... During exercise your muscles must burn calories to fuel their contractions. The conversion of calories from their stored nutrient state to the form that can be burned by your muscle cells is achieved, during aerobic exercise, through the process of cellular respiration, which requires oxygen, and the delivery of oxygen through your bloodstream to your active muscle cells is directly related to your heart rate. It is this relationship that allows you to predict your energy expenditure (i.e. calorie burn) from your heart rate. Essentially, with increased exercise intensity your muscles must burn more calories, and so your heart must beat faster to provide the oxygen necessary to convert those calories to the form of energy that can be burned by your muscles.

    Back to the question in hand, which is swimming. It depends on lots of things, including technique and speed. A friend of mine swims faster than me but burns fewer calories (measured with hrm) because she has miles better technique than I do. She burns more calories cycling than I do because I am technically a better cyclist and more efficient at getting up hills. All databases are based on averages of averages, which is why I wear a hrm for all my exercise. Might not be exact but will be better than any online databases, including MFP
  • 3dogsrunning
    3dogsrunning Posts: 27,167 Member
    Heart rate does not affect calories burned. There is a relationship between VO2 and heartrate during moderate intensity exercise that allows for an estimation of calories burned. So I would not discount it based on HR alone.

    As for the question about swimming, I am pretty skeptical myself. I usually log at the lowest insanity and under estimate my time.

    You say heart rate doesn't affect calories burned and then say that there is a relationship... During exercise your muscles must burn calories to fuel their contractions. The conversion of calories from their stored nutrient state to the form that can be burned by your muscle cells is achieved, during aerobic exercise, through the process of cellular respiration, which requires oxygen, and the delivery of oxygen through your bloodstream to your active muscle cells is directly related to your heart rate. It is this relationship that allows you to predict your energy expenditure (i.e. calorie burn) from your heart rate. Essentially, with increased exercise intensity your muscles must burn more calories, and so your heart must beat faster to provide the oxygen necessary to convert those calories to the form of energy that can be burned by your muscles.

    Back to the question in hand, which is swimming. It depends on lots of things, including technique and speed. A friend of mine swims faster than me but burns fewer calories (measured with hrm) because she has miles better technique than I do. She burns more calories cycling than I do because I am technically a better cyclist and more efficient at getting up hills. All databases are based on averages of averages, which is why I wear a hrm for all my exercise. Might not be exact but will be better than any online databases, including MFP

    It can be used to predict calories burned but heart rate itself does not burn calories. Yes, if your heart rate is up you are probably burning more calories. There are many situations where am elevated heart rate is not related to calories burned.
    If two people, one with a higher heart rate and one with a lower, that weigh the same do the same exercise at the intensity for the same duration they both burn the same amount of calories regardless of the difference in heart rate.
    People around here get too wrapped up in heart rate with regards to calories being burned.

    Calories burned is weight and intensity. Heart rate can be an indicator of intensity
  • dynamiteshell
    dynamiteshell Posts: 2 Member
    You burn more calories at a lower heart-rate when swimming because of the water pressure...

    "The pressure of water causes a shift of blood volume from the periphery of the body to the thorax. This increases venal pressure and so leads to a decrease in heart rate of up to 20bpm lower in water than on land. The same intensity of exercise at a lower heart rate. Only in the pool!"
    Source: www.swimming.org/swimfit

    So forget about heart-rate when swimming. Just swim continuously so you you feel like you're working hard and getting out of breath, and not just gliding up and down the pool or resting!