It's a great motivator to see the "calories burned" light up on many of the electronic cardio machines, but realize it's not based on all the necessary facts to be accurate. The sad truth is that that number is usually inflated. If you think that you burned enough extra calories this morning to eat that cheeseburger for lunch, think again. Even when you specifically enter your gender, weight and age, your estimate (yep, it's just an estimate) could be off by tens to hundreds of calories. Hundreds! In fact, the majority of cardio machines manufacturers test their equipment on big, muscular guys and not your everyday person. Because of this, the estimated calorie burn that is programmed into the machine is based on a large man who burns tons of calories just breathing. If you're a female, this is specifically problematic. So, literally, tread lightly!
On average, most people burn about 100 calories per mile walked or ran. If your cardio machine’s calorie count registers way more than this, then err on the side of calorie caution when planning your meals for the rest of the day. In general, all machines and online calculators offer mere estimates of calories burned, so never take them as fact. A better and more accurate way to estimate your calories burned for any workout is to that estimates calories burned based on your actual workout intensity.
The built-in heart rate monitors on cardio equipment sure are handy. After all, they sense your pulse (heart rate) from your fingertips and hands! However, your pulse isn't as strong or accurate when measured from your hands as it is when it's measured closer to your chest. Plus, these displays rely on sporadic data, which is only available when you hold on to the console or handles. This is typically a bad idea, especially if you're running or walking fast or if holding on compromises your form or causes you to lean into your hands—a sure sign that you're not really working as hard (or burning as many calories) as you may think.
Remember that when it comes to exercise, using cardio machines or not, everyone is different and no machine can really be accurate for every work out.