Are you a gym user? As much as I like to get fit outside, indoor cardio machines are a convenient way to exercise – especially on wet days in winter. It can be a good way to get in shape and improve your fitness level.
But which are the best cardio machines for calorie burn and weight loss? How long should you spend at the gym and how accurate is the calorie estimate provided on the machine readouts?
What Cardio Machine Burns The Most Calories
According to Harvard Medical School, here’s a rundown of popular cardio machines and how many calories they burn in 30 minutes, based on a 155-pound person.
- Treadmill (12 min/mile): 288 calories
- Elliptical machine: 324 calories
- Stationary Bike (moderate effort): 252 calories
- Spin Bike (12-14 mph): 288 calories
- Rowing Machine (moderate): 252 calories
- Stair Stepper: 216 calories
The elliptical machine wins easily but before you rush off for your workout, keep on reading!
These figures don’t give the full story. There’s no mention of effort level for the elliptical trainer and running at 12 min/mile pace on the treadmill could be really easy for one gym-goer and extremely hard for the next. It all depends on fitness levels.
Differences in the effort level, machine setup, and how you use the machine, will make big differences in calories burned.
How To Calculate Calories Burned For Cardio Machines
In nutrition, the unit typically used is Calories with a Capital C. It’s a measure of energy where 1 Calorie is actually 1 kcal or a thousand little calories.
Originally, a calorie was defined as the energy required to raise the temperature of one gram of water by 1°C. It’s not a very reliable measure and the definition has been improved over the years to the more scientific value of 1 kcal = 4.18 kJ
Metabolic Equivalents (METs)
To calculate the number of calories you’ve burned during a given activity, scientists use a unit called the metabolic equivalent for task (MET). This unit measures how hard your body is working.
✅Find the MET value of cardio activities in this table and use my Calorie Burned Calculator to find the total number of calories you’ve burned in the gym.
One MET is defined as the amount of oxygen consumed while sitting at rest and is equal to 3.5 ml O2 per kg body weight x min.
Different tasks and exercises will clock different METs; for example, running can be anywhere from 7 to 13 METs, depending on speed and effort. This is the science behind those calorie-burned displays on your cardio machine.
Find your METs and you can find out how many calories you’re burning. You can refer to the Compendium of Physical Activities which is a giant list of activities and how many METS they “cost”.
Use METs To Calculate Calories
Cardio machines calculate calories from METs using the following formula:
Calories = 1.05 * MET* T * W where T = time measured in hours and W = weight measured in Kg.
For example, let’s say you weigh 155lb and you used an elliptical trainer at a moderate effort for 30 minutes.
The Compendium of Physical Activities lists an elliptical trainer (moderate effort) with a MET value of 5.0.
155lb is approximately 70 Kg
30 minutes = 30/60 = 0.5 hours
Enter these values in the calorie-burning formula and you get:
Calories = 1.05 * 5 * 0.5 * 70 = 183.75
Using an elliptical trainer for 30 minutes, you would burn approximately 180 calories.
Differences In Calories Calculated
Hold on – the Harvard results give 324 calories! Why the big difference?
These are the calculated values for each cardio machine activity based on MET values:
- Treadmill (12 min/mile) MET value 8.3: 305 calories
- Elliptical machine (moderate effort) MET value 5.0: 180 calories
- Stationary Bike (moderate effort) MET value 6.8: 250 calories
- Spin Bike MET value 8.5: 312 calories
- Rowing Machine (moderate effort) MET value 7.0: 257 calories
- Stair Stepper MET value 9.0: 330 calories
Some results are very similar to the Harvard results and some are completely different.
It all depends on the MET values used and the accuracy of calculating MET values for different cardio machines and different intensities.
Calories Used On The Elliptical Trainer
Estimating calorie burn is all about the data. The problem with elliptical machines is the lack of information. The machines don’t replicate natural motion so the available data is limited.
It doesn’t help that elliptical machines differ from one manufacturer to the next so there are a huge amount of variables to consider.
A recent study by Stanford University looked into the accuracy of wrist-worn devices for calculating data. These were reasonably good at measuring heart rate but terrible at measuring energy expenditure – don’t expect your cardio machine to be any better.
That doesn’t mean you won’t get a good workout on an elliptical machine – it’s a good way to raise your heart rate without pounding your joints and will give you a full-body workout. It’s my go-to piece of equipment for a HIIT workout to challenge my aerobic system, especially when recovering from an injury.
The pitfalls of the elliptical trainer for calorie-burning are mainly because it’s less weight-bearing and isn’t a natural motion. The cardio machine will work your entire body but the increase in heart rate from working your arms as well as your legs doesn’t translate as well into burning calories.
But don’t avoid the elliptical trainer just because the number of calories used tends to be overestimated. It’s still a great machine for a low-impact full-body workout – good for cross-training and recovery days.
Calories Burned On The Treadmill
The treadmill is a great cardio machine and the calorie counter is pretty accurate. There’s a lot of data for the natural motion of running so as long as you input your weight, you should get a reliable reading.
The treadmill is one of the best ways to burn calories in the gym. Even at the relatively slow running pace of 12 min/mile, a 155-pound person is still burning about 300 calories in a 30-minute session.
It won’t take into account your fitness level, (if you’re unfit you’ll be working harder to maintain a 12 min/mile pace), and make sure you don’t use the handrails – these will make dramatic differences to your calorie burn.
Calories Burned On The Stationary Bike
Bikes support your body weight so readouts of calories used can be accurately based on your power output in Watts. This makes the readouts from the exercise bike highly accurate.
The only way you’re going to start throwing the results will be by standing up on the pedals. This can underestimate your readings by about 15%. Why? Because of the extra effort of no longer being weight supported.
Calories Burned On The Spin Bike
A spin bike class is a great way to get fit – high intensity with a huge amount of time spent out of your seat. The spin bike is less upright than a stationary bike and it’s better at replicating a normal cycling position.
Again, calories used will be based on your power output in Watts so expect a good degree of accuracy although time spent out of the seat makes it harder to measure.
Cycling is a sport with a high degree of data to draw on and compares well to using a spin bike. But if you’re in a spin class and doing a lot of arm exercises while you cycle, you may get a tougher workout than the calorie counter suggests.
Cyclists are some of the fittest people on the planet, so get on that spin bike if you want a good calorie-burning workout.
Calories Burned On The Stationary Rowing Machine
Rowing is another activity that supports your body weight and power output is measured in Watts. Expect accurate readings!
It’s a terrific exercise for working your entire body and uses multiple muscle groups – working your upper body and building a strong core, back, and legs.
You’ll get more bang for your buck on the rowing machine than on many other cardio machines. It’s low impact, so there’s little stress on your joints, and it’s a natural motion.
The only downside is that you need a certain level of fitness to be able to row effectively. If you’re new to the gym, this might not be the best machine to start with.
Calories Burned On The Stair Climber
I find the stair climber is a great option and always incredibly hard work, especially on your lower body but the calories used really depends on the intensity and how you use it.
Double over and put all your weight on the console and you’ll burn fewer calories – so make sure you’re using the climber properly if you’re looking for good results.
METs will vary from 4 to 9 depending on your pace. That’s a difference of between 140 and 330 calories burned for a 155-pound person. So make sure you keep that intensity up for maximum calories burned.
Related post: Stairmaster vs. Treadmill: Which is better for weight loss?
Which Cardio Machine Is Best For Hitting Your Fitness Goals?
All of these cardio machines burn calories and will give you a good cardio workout. It’s just that calorie counting isn’t always accurate. A high-intensity interval training (HIIT) session on a cardio machine will give you the best results for burning calories in the shortest amount of time – it’s just that if you’re new to exercise you’ll find it hard to maintain intensity for long enough and you could end up burning fewer calories overall.
The best way to get fit for beginners and burn fat is to maintain a moderate pace for 30 minutes. This way you’ll burn a significant number of calories. Your best option is using the treadmill or spin bike.
When you’re trying to lose weight, include strength training for the best workout – it’s a way of increasing your metabolism and caloric burn. For better results, work with a personal trainer to make sure you’re using the equipment properly and getting the most out of your workouts.