Most people burn between 6 and 10 calories per minute on a sustained basis (6 on the moderate end, 10 is more vigorous). A fit person pushing themselves might burn 12-14 calories per minute.
I don't know how hard you were working, but on this basis, 400 calories in 40 minutes does not seem unreasonable.
Fitness Minutes: (6,042)
2/5/14 3:04 P
I've been doing spin classes for a little over a year (met my goal of 100+ classes for 2013). I have worked with a sports physiologist to have both my resting metatolism and my VO2 Maximum tested (I've had this done three times over the last few years.
With the results of these specific tests, he was able to give me a grid showing exactly how many calories I burn in a hour at various heart rates..
During a typical spin class I maintain an average heart rate of abound 140. At this rate I burn roughly 850 calories. My base metabolic rate is about 2350 a day or about 100 per hour. My NET calorie burn for a one hour class is, therefore around 750.
The bikes themslves always read much lower than this when showing calories burned (anywhere fro 350 to 500). The reason for this is that the bike only uses the Watts you generate to make a guess about your calorie burn. A heavier person for instance (I'm about 180), will burn many more calories when spinning in a standing position than a light one because they are moving their own weight as well as pushing the pedals. Likewise, doinng lots of jumps will burn more calories than just sitting although the watts will be the same.
Fitness Minutes: (10,640)
1/14/14 12:50 P
I do a 45 minute spin class 3 days a week and according to my HRM I burn anywhere from 260-300 calories per session. I weigh 125 lbs and am a marathon runner and triathlete.
I do think 400 calories is a little high. However, a lot depends on your current fitness level, the intensity you have the bike at, and your current weight. I do know there are people in my class that burn well over 400 calories (according to their heart rate monitors).
The best way to get an accurate number is to use a heart rate monitor.
1/13/14 7:12 P
It is on the higher end, but it also depends on how much you weigh. The more you weigh, the more you'll burn. A heart rate monitor is going to give you a more accurate estimate of calories burned based the intensity of your workout.
Hope that helps,
Fitness Minutes: (3,502)
1/13/14 6:25 P
I have recently gotten back into spinning. In the fitness tracker for a 40 minute spin class SP said that I burned over 400 calories. I worked very hard during the class, but I still feel like the amount of calories burned during the class seems very high. I do not know if adding the extra 400 calories to my daily food intake will be detrimental. I try to eat wholesome food from all my exercise calories such as fruit, veggies, and nuts. Does 400 calories seem like a lot for 40 minutes of exercise?