3 Reasons To Never Trust Estimated Calorie Burn On Cardio Machines

 by Pat Koch, CSCS, CISSN | March 4, 2013

If you are among those who constantly worry about how many calories you burn, you’ll learn two important ideas in this article:

1. You can’t trust estimated calorie burn on cardio machines, because they are likely inaccurate, and
2. Worrying about calorie burn is not the path towards fitness success over the long term

Here are 3 reasons why estimated calorie burn on cardio machines is likely inaccurate:

Reason #1 – Estimated Calorie Burn Includes Your RMR

Everyone has a unique amount of calories they need to ingest to maintain their body weight. This is referred to as your resting metabolic rate (RMR), meaning that if you lay down all day and didn’t move you would still be burning calories just by being alive (breathing, organ function etc.) Your RMR is a huge determinant of how many calories you need to consume each day.

Treadmill and other cardio machines include RMR within their calorie estimates. So the calorie estimate you see on display is not just how many calories you have burned during your activity, but also how many calories you have burned just being alive during that time. This leads to an over inflation on how many calories you burned from exercise.

For example, if a 175 lbs man exercises for a half hour at a moderate pace, he will burn around 270 total calories…according to his machine. For an accurate count, he’d need to subtract around 40 calories from the 270 for the calories he used just by being alive for the half hour.

The greater your workout time and the heavier you are, the more overinflated the number becomes. If you rely on exercise to create a large caloric deficit, you’ll want to consider this over estimation.

Reason #2 – Cardio Machines Assume You Are A 180lb Man

Calorie estimations are very difficult because individuals vary so widely. In order to correctly estimate caloric expenditure, many factors need to be considered: total energy cost of exercise depends on weight, gender, age, height, amount of muscle, and disease state.

Treadmills rarely take the aforementioned into account. If you are exercising on a cardio machine and fail to give it any input such as your height, weight, or age, your estimates will be very off. The cardio machine will use a default runner based off a typical man weighing 160-180 lbs. If you weigh less then a typical man your calorie estimates will be over inflated, and vice versa.

Reason #3 – Cardio Machines Do Not Take Into Account Exercise Efficiency

Efficiency can be described as how easily your body uses calories to do work. Someone who is highly efficient would be able to do more exercise using fewer calories.

There are many factors that effect exercise efficiency1 that may also throw off the estimated calorie burn shown on a machine:

1. Muscle Fiber Composition – Fast twitch fibers are less efficient then slow twitch fibers. Thus your efficiency and potentially calories burned will depend on your genetic disposition and your overall training history.

2. Exercise Technique – Improved technique produces fewer extraneous body movements and increases efficiency.

Take for example, a competitive swimmer vs. a person who rarely swims. If asked to travel the same distance at similar speeds, the experienced swimmer would burn less calories due to smoother strokes and an understanding of buoyancy that make the activity require less effort.

The same applies to cardio machines. Although they are less technical then swimming those who improve their form will have different energy cost then those who are unfamiliar.

A relevant example is holding up your body on the handrails on a machine like the Stairmaster. Bracing yourself with your arms makes the activity easier, yet the machine fails to adjust for this measure.

3. Fitness Level – More fit individuals perform a given task at a higher efficiency because of decreased energy expenditure from non-exercise tasks such as temperature regulation, increased circulation, and waste removal.

The above is not meant to bash using cardio machines in your quest to lose fat. Increasing efficiency is not necessarily a bad thing for fat loss. With an increase in efficiency also comes with an increase in ability. More efficient exercisers can push themselves harder.

In fact, best fat loss practices encourage you to increase the intensity of your cardio workouts, not necessarily the duration.

How Do You Accurately Estimate Calorie Burn From Exercise?

Over all, there’s too much variation to get an accurate estimation of how many calories you burned if you rely on the number calculated by a cardio machine. If you really need the number of calories burned, it may be more accurate (and more time consuming) to calculate manually, or to rely on a calorie burn tracker like BodyBugg, which has its own limitations.

At the end of the day, it is important to get your diet in check so you don’t have to rely on the “burn it off” mentality. Understand that no amount of exercise will get you shredding fat if you’re not maintaining it with a proper diet. Attempting to out-exercise a bad diet is a losing proposition.

Consider weight training, followed by interval training, as your preferred method of burning fat. Throw in steady state cardio if you don’t want to limit your workout to strength training, but remember…don’t trust the machine.

Fuck. So I'm fat and my cardio machine lies to me. D:

I don't get this part...

"For example, if a 175 lbs man exercises for a half hour at a moderate pace, he will burn around 270 total calories…according to his machine. For an accurate count, he’d need to subtract around 40 calories from the 270 for the calories he used just by being alive for the half hour."

Why would you need to subtract 40 calories from the 270 for being alive? Wouldn't being alive burn calories instead of add calories. It isn't like he just ate a couple of nuts while working out.  edit- I suppose I get it now.  The machine is adding 40 calories to the overall work out due to him being alive?  So the work out burned 230 and being alive burned 40 calories...  Big deal.

Simple. You would have burnt those cals anyway. But people are assuming wow I burned 270 Cal more through the workout because the machine said so. But infact those cals were not burned additionally to the BMR. People on diets will mess up their calorie counting (if they do it). Or some people think 1 hour on the machine thats 540 Cal now I can eat this 500 Cal product additionally to my daily foodintake and I will still have a 40 Cal deficit and lose weight longterm. But they actually have a 40 Cal surplus due to not knowing that the calculation accounts for your BMR too.

Yea, I see how it could throw some people off.  I just can never get into the total calorie counting mode nor would I ever want to.  First I would assume perhaps that my daily intake would be around 2,500 (because I am a big guy).  Sure I sometimes look how much calories are in food but I usually just try to do it the "right" way through controlling portion sizes and eating actually healthy food.  I just started working out again and I do enjoy using the eliptical machines.  I am going to rotate between cardio and weight lifting.  I guess I'll take some of this to heart and just subtract about 50-100 calories from what the machine says to get a more accurate total.  I already had the mentality that the totals are inflated a little / not accurate.

I get that the cardio machines are off on those estimates, as my sister who is a fitness guru constantly reminds me. I mainly use them as a ballpark measurement of how hard I've gone, not so much how many calories I actually burned. 

With regards to proper diet, that definitely helps, but since I've started my fitness regimen over a year ago, I've lost a nealy 30 lbs and I really didn't change my eating habits that much, and I haven't exactly been eating healthy. I think my main change was more water, less soda, and cutting the huge late night snacks. But the point being, I don't think you have to drastically change your eating habits or go on these crazy diets, as long as you keep your workouts consistent.

Instead of using cardio machines... do Hindu squats like a real man.

I know, counting calories exactly has this obsessive feel and not many do it. But alot of people seem to fail for that reason. 

I think people should try it more often. Whats important is to do it once for a prolonged timeperiod. You will automatically develop a more precise sense for the calorie contents of food and this can help to keep your goal weight. Even when you stop after a few weeks or months. With the Basics like 1g proteine = 4 Cal 1g Carbs = 4g 1g fat = 7 Cal (Actually its 9 but the body needs 2 Cal to for making ketones out of fat or else its not usable) its possible to see caloric contant by looking at stuff with experience.

Cardio and weightlifting for weightloss ist actually an interesting topic, maybe you already know all of this maybe it will help you:

 Weightliftings is a very good way to lose fat cells. 1 pound muscle burns 4 times more cals than one pound fat and this 24 hours even while you sleep. So effectively you raise your BMR longterm and it actually forces you to eat to keep your weight from a certain point onwards. Since muscles are denser and heavier than fat your scale will not necessarily reflect the progress you made. You can build alot of muscle weight before its visible that you do weightlifting which some people, especially women are afraid of. The act of weightlifting will not burn as many cals as the same time cardio activity. It will however stimulate a muscle tissue growth phase after a while which repairs and strengthens the muscle fibers. This process will use up alot of energy and take a day or longer. Additional weightlifting in this phase will slow down the growth process since your body will have less tme building tissue and spend more time repairing tissue. That effect is known as overtraining the recovery phases will decrease when you keep training for long. 

It can be accelerated beyond natural limits with certain hormones. This often has consequences and can permanently change the level of natural hormones and leads to aromatization of testosterone which increase the Oestrogenlevels. In males it will cause problems like gynecomastia. It can lead to milk production in a male and pain at this stage surgery is often the only option. It stops production of testosterone in the gonads. Shortterm at first but can lead to a complete permanent shutdown. Also an increase in DHT levels can occour. DHT is toxic for hair follicles. This was just a sidenote incase someone reading this by chance gets a wrong idea.

 I think the potential weightlifting has for weightloss is massively underrated. 

Cardio burns cals fast and keeps your metabolism from decreasing on a caloric deficit if you target your heartrate sweetspot long enough but won't help building musclemass which inturn increase your daiily caloric needs longterm even without constant training. Obviously muscle will shrink without activity but very slowly if you do nothing in the right way.

 This helps with the rebound people experience after diets since they can get back to eat more again and have on and off periods of weightlifting.

Muscle building takes very long but once you are there its much easier to maintain the mass. It requires a certain level of stimulus but regrow way faster than the firsttime. Nutrition is key and regular/enough protein also enough calories and limiting certain habits.

Cardio is an excellent way to strengthen your cardiovascular system and health but as soon as you stop it your weight will go up or you have to decrease food intake again.

If you are already big and aim for weightloss. You have a certain advantage. The muscles are already there. Big people train all day every day just by walking around and doing something and  have significant amounts of muscle tissue. Its  easier to lose fat than to gain muscle.

 But sadly without actually doing anything except restricting calories your body tents to burn muscle before it uses fat reserves so more than half of the weight people lose is actually muscle this inturn leads to a  lower BMR and you need to eat less and less to keep losing weight. 

The trick is to keep the muscle tissue while losing fat and its an extremly fine line to go. But its possible the start is hard once on track its easier. Here some general stuff:

First of 1kg body fat equals 7000 cal  available. To lose 1kg bodyfat you need to consume 7000 cal less than you burn. Seems simple however >50%  of that are usually muscle. So you actually need to burn 11000 cal and lose 2kg weight to lose 1kg fat. But there is still waterweight. You don't need to lose more than 11000 cal to lose water weight but if your scale shows 3-5kg less after a few weeks you haven't actually lost that much, its still just 1kg fat the other kg is dense muscle tissue the rest is water which can be, depending on your food, 1-5kg or even more.  Less salt less carbs and alot of fluid intake make your body let go of water.  Just by doing that and not changing anything else you will lose a lot of weight. But it comes back just as fast as it went away. Numbers on a scale must be interpreted correctly and are not a sign of progress. On the other hand its easy to gain 5kg but its mostly water it takes time for the body to build fat or lose it

It also takes time to start burning fat. The Body first uses up all the readily available nutrients after a while, when its all depleted it takes the glycogen storage. This  keeps you running for days without any food before its depleted. The majority of the weightloss people experience at first is glycogen and water  this will go fast its actually quite benefital to start eating very little for a few days and be hungrwhen trying to lose weight. Aslong as there is easy access to glycogen your body will not start losing fat in substantial amounts. After glycogen comes muscle fibers and fat.

Its possible to get your body to burn more fat and not mostly muscle . Its important to get enough protein (About 100g) and keep your muscles periodically regenerating (aka train/rest/train) but still have a deficit of BMR-500. Guided movements like machines provide are not actually a good thing it forces your body into an unnatural movement and targets a certain muscle while the muscles which would have stabilized your movement will not be needed. Without them also getting stronger the strength gain will be not effective and your muscle proportions will suffer. So freeweights with gradually increasing weight targeting all muscle groups within a week and giving a targeted muscle 24-48 hours time to recover with additional cardio and a 500 cal deficit, should let you lose weight for a long time,  before food readjustments must be made. Once at the goal you would need to increase your caloric intake to 500 + BMR and increase the weights at a faster pace. Losing 1kg fat a month + X  of water is the upperlimit to whats possible without bringing the metabolism to the knees. The muscle gaining process goes slower 500g a month weight gain is the upperlimit anymore and its water significantly more and its fat. Now all you have to do is gain muscl and up your calories while seeing 1kg weightgain month. 

Once build fatcells will never go away just shrink, its easier to replenish existing fatcells even though it still takes a while. They also produce a certain hormone called leptin which spikes appetite so once overweight people can easier get back into old habits. This is why I believe that the best way to keep unwanted body fat of is to raise your BMR permanently in order to end up eating normally. Its easy to forget that in order to keep weight and get the possible health benefits later. People need to keep running like on a diet and eating like on a diet for the rest of their lifes. Also BMR decreases naturally with age. An example: If you are 20 and ideal weight and get lets say 2500 Cal the exact amount you burn. Now you do every day the same things and keep eating 2500 cal every day for 20 years you will be overweight with 40 because your internal biochemical processes slow down with age. But these processes burn calories so if they slow gradually down you will just need 2000 cal instead of 2500 even if nothing else has changed. 

Why I even wrote all of this: 

Well this thread reminded me of an Article I read that long term weightloss is impossible to achieve for more than 9 out of 10 people . I think its because the underlying factors and mechanisms are simply unknown or just partially known and people just won't know which particular mistake they made or what problem they didn't pay attention to. And spend too much time doing stuff which is harder or not effective enough so they get frustrated and see not enough progress or lose it all very fast . But I think its possible to customize a certain food and trainings routine according to personal needs which allows after 3 years to gradually go back into old habits andkeep the weight down through random but regular traingsphases.  

The things I described above are just rough descriptions but it basically works that way for everyone , adjusting it to certain conditions, a few tweaks in nutrion and a proper trainingsplan to make it achievable should be done. It should be possible to exactly pinpoint the personal sweetspot  between weight time foodamount and workout intensity.

 When I think about it  there can be so many things customized with data about the physiology, biochemistry,  daily routine and psychology of someone to work out the perfect way for quick healthy and permanent weightloss if you have total control over the environment. It could be done like the care pro athletes get (without the drugs) but with focus on easy and efficent weightloss.

Would be an interesting long term study to follow and see if people still fail after 15 years

people shouldnt be running just to burn calories in the first place. burning 300 calories is a cookie lol

If you are roughly a 180 pound man give or take say 10 pounds, cardio machines are a fair accurate indicator of calories burned. If you are say 160 pounds and below or 200 pounds and above cardio machines can be inaccurate to measure how many calories you have burned. A person who weighs more travelling at the same speed as a person who weighs less will burn more calories.