how do I calculate calories properly?

Question

I go on the stationary bike on resistance level 15/ 250 watts / 80-110 RPM (it fluctuates) at about 30km/h and the machine says I burn 1800 calories in 80 minutes. I don’t know if it is completely accurate. I do feel like I put in a lot of work, my legs burn and I am dripping in sweat by the end of it. It was very hard at the start but now i feel it is a lot easier and can do 30 minutes much easier, at the start I couldn’t even do 15 minutes without getting out of breath. If someone could tell me if what I’m doing is right and if the calories I’m burning is correct. I have been doing 30-60 minutes daily for the past month and eat around 2000 calories a day. One day out the week I do 90 minutes along with intermittent fasting. I have lost 9kg in a month, so I do feel like it is working but I don’t want to over estimate what I’m burning and eating too much.

Answer 1

Hi I'm Linda and my degree is in Exercise Physiology and P.E. The answer is tricky because your current weight must be added to he equation and what the exercise machines don't tell you is that usually what their formula says you burn may be somewhat accurate, but usually at rest you would burn about half of what they say you are burning. It may seem confusing, but you are probably only burning about 900 additional calories or half of what they say. When I personal train someone, I never try to set up exercise program by calories burned as this can vary so much. This goes hand in hand with the weight loss you have experienced so far. If you were really burning 1800 3-4 days a week while only eating 2000 calories per day...you would not be functioning well probably mentally and physically. Hope this helps.