Question

Rmeikel

I am logging exercise. Do I log the number of calories it says on the machine, or do the number of calories it says here for a certain exercise. My example is the stationary bike. I averaged 14.3 miles per hour for 25 minutes. The machine told me I burned 193 calories. The information here told me I burned a lot more. Does anyone know how this works?

absie107

this is how it works: the system is not perfect. I would say average the two... just about everything you're recording or doing is a ballpark figure. you aren't going to eat exactly the number of calories you record because everything varies. food is not a commodity as people would have you think. it comes from that which lives, and thus nothing can possibly be the exact same as anything else. one banana is not exactly as big as another. again, just average the two and use that. you'll be fine.

abricklin

Based on my HRM at the gym on the elliptical, stairmaster, and bike (not treadmill) the machines overestimate by 25-30% (FOR ME!) so I, personally, would NOT average MFP and the machine. I would count the 193 for an even 150 calories. One of the biggest mistakes people make is underestimating food consumption and overestimating exercise burn. Err on the side of caution for both.

DrBorkBork

MFP tends to be pretty generous on calories burned. I would go with the machine until you can afford a heart rate monitor. Better to be under on cals than over

TrainingWithTonya

Calories burned depends on how much mass you are moving while you are using the machine. The standard for exercise equipment is that it is using a basic formula for the METs (metabolic equivalents or an estimate of how much times the normal metabolic rate of the individual each activity requires) needed for a particular activity multiplied by a standard weight of the participant of 70kg (154 pounds). If you weigh more then 70kg or 154 pounds, then you will burn more calories doing the same activity as someone who weighs 70kg or 154 pounds. The formula that is used here is based on the weight you entered in your profile, again multiplied by the METs needed for the activity. So, the most correct number for you specifically is what you get from MFP not what is on the machine.

abricklin

Calories burned depends on how much mass you are moving while you are using the machine. The standard for exercise equipment is that it is using a basic formula for the METs (metabolic equivalents or an estimate of how much times the normal metabolic rate of the individual each activity requires) needed for a particular activity multiplied by a standard weight of the participant of 70kg (154 pounds). If you weigh more then 70kg or 154 pounds, then you will burn more calories doing the same activity as someone who weighs 70kg or 154 pounds. The formula that is used here is based on the weight you entered in your profile, again multiplied by the METs needed for the activity. So, the most correct number for you specifically is what you get from MFP not what is on the machine.

But don't most machines require you to enter your age and weight/mass? Your explanation also would not make sense in that someone that weighs MORE should be burning MORE than the machine says yet, as I had noted, according to most peoples' HRMs calories burned are significantly lower than the machines (and these people, on average, weight more than 154 lbs)

TrainingWithTonya

Calories burned depends on how much mass you are moving while you are using the machine. The standard for exercise equipment is that it is using a basic formula for the METs (metabolic equivalents or an estimate of how much times the normal metabolic rate of the individual each activity requires) needed for a particular activity multiplied by a standard weight of the participant of 70kg (154 pounds). If you weigh more then 70kg or 154 pounds, then you will burn more calories doing the same activity as someone who weighs 70kg or 154 pounds. The formula that is used here is based on the weight you entered in your profile, again multiplied by the METs needed for the activity. So, the most correct number for you specifically is what you get from MFP not what is on the machine.

But don't most machines require you to enter your age and weight/mass? Your explanation also would not make sense in that someone that weighs MORE should be burning MORE than the machine says yet, as I had noted, according to most peoples' HRMs calories burned are significantly lower than the machines (and these people, on average, weight more than 154 lbs)

Yes, the machines ask you to put weight in, but it doesn't necessarily use it for the formula. They aren't very complex computers on those things so they aren't necessarily capable of the more complex calculations with different weights. Then you also get into the aspect of how trustworthy are the manufacturers of the equipment or how are they cutting corners to save on their costs. I have been taught by my professors (I'm currently in an Exercise Physiology Bachelors program.) to go by the METs and weight and that is what MFP uses.

As for heart rate monitors, they use heart rate and an estimate of stroke volume to determine cardiac output and calorie burn. Unfortunately, cardiac output can vary from person to person because of differences in age, posture, body size, presence of cardiovascular disease, and the level of physical conditioning. While these things can be great if you know you're in excellent physical health and input your information into the HRM, they are estimating calories based on how much blood is moved in the body, not how much mass is moved in the exercise. Basic physics says that you have to have the same amount of energy to move the same amount of mass. So a 200 pound fit person would need the same amount of energy to do the same amount of work as a 200 pound unfit person. The difference would be that the fit person has a more efficient heart so they are getting more blood to the body with less beats of the heart due to the fact that they have increased their hearts stroke volume through training. But while their heart rate is lower, they still need the same amount of energy (calories) to produce the movement, they are just more efficient at getting the oxygen to the muscles so that it can be used to burn fat as the fuel source. So, from all that I've been taught a heart rate monitor is more accurate for average people, not people who have been training for a while or people who have been severely deconditioned because it is using an average stroke volume to determine cardiac output.

All in all, though, they are all estimates. Pick one and stick with it so that it is comparable over the years as to what you've done and don't stress it. The stress of worrying about which one is best can cause increases in cortisol levels which will increase fat storage.

Azdak

Calories burned depends on how much mass you are moving while you are using the machine. The standard for exercise equipment is that it is using a basic formula for the METs (metabolic equivalents or an estimate of how much times the normal metabolic rate of the individual each activity requires) needed for a particular activity multiplied by a standard weight of the participant of 70kg (154 pounds). If you weigh more then 70kg or 154 pounds, then you will burn more calories doing the same activity as someone who weighs 70kg or 154 pounds. The formula that is used here is based on the weight you entered in your profile, again multiplied by the METs needed for the activity. So, the most correct number for you specifically is what you get from MFP not what is on the machine.

HRMs tend to underestimate caloric burn at lower intensity levels (esp Polar). Plus, many/most Polar users either do not put in accurate setup information into their profiles or never update it. As a result, the calorie amount for a specific workout intensity goes down over time, not because the person is burning fewer calories, but because that particular intensity represents a lower percentage of their HR max than before (due to training). The example I always use is running 6.0 mph. The energy cost of that activity is approx 10 METs--no matter who is doing the activity. A beginner who has a VO2 max of 12 METs running at the speed represents 83% of max, which is really hard work. A trained runner with a VO2 max of 18 METs will only be working at 55% of max, which will feel fairly easy. If the person with a 12 MET max increases their max level to 15 METs through training, running at 6 mph will then be only 67% of max, which is a moderate effort. Because this speed now represents a lower percentage of their maximum, the heart rate at this speed will now be lower than before--notably lower. However the person is still working at 10 METs when running 6 mph. The HRM does not know that--the HRM only knows that a certain HR is a certain percentage of that person's maximum. If the person does not update their HRM to show that their max fitness level is now 15 METs, the HRM will assume that they are now working at 67% of the previous max of 12 METs. Instead of calculating calories based on 10 METs, the HRM now calculates calories based on 8 METs (67% x 12).

HRMs do not measure anything except heart rate. They estimate calories burned based on heart rate and the user's profile. If that information is not accurate, then the HRM will be off to the same degree.
But don't most machines require you to enter your age and weight/mass? Your explanation also would not make sense in that someone that weighs MORE should be burning MORE than the machine says yet, as I had noted, according to most peoples' HRMs calories burned are significantly lower than the machines (and these people, on average, weight more than 154 lbs)

Rmeikel

Wow -- This is exactly why I love this site. So much information! The machine I was using did not ask me my weight, which is significantly higher than 154 lbs. Thanks for the advice every one. I did sweat, and I did work out for that 30 minutes(plus Shred, and walking the dogs), so both of those things are successes in and of themselves. I just want to make sure I am recording the right thing!

I try to stay under my calorie goal anyway so that if I am underestimating food, or over estimating exercise, I can still lose!