2012 Motobecane Fantom CXX, 2012 Motobecane Fantom CX, 1997 Bianchi Nyala, 200? Burley Rock 'n Roll
Originally Posted by Wesley36
While technically true, this implies that there is some degree of accuracy with calorie estimation that does not involve a power meter (ie HR). HR-based calorie estimation is based upon so many dodgy assumptions that it is not just basically meaningless, it is totally meaningless. In fact, it is worse, because it appears to actually be measuring something, when it has only taken a stab in the dark and given a nice valid looking number.
I don't regard the calorie estimates by my Polar FT7 to be accurate numbers, but I suspect that they're better than you would give them credit for. I've been estimating calories burned on my Kurt Kinetic trainer by finding the average power I produced using their published power curve, and then using the typical formula for converting power into calories (although to use that you need to make an assumption about your own personal efficiency at converting food calories into power at the pedals). I acknowledge that using a calibrated power meter is generally going to more accurate than the Kurt Kinetic power curve, but the power curve number is probably a decent estimate.
I'm finding that the Polar FT7 estimates calories about 25 - 35% higher than my calculated calories. The Polar estimate is higher when my average heart rate is higher during a given session, even if the average power is the same. The Polar appears to be estimating calories per heartbeat, and it doesn't have a way to know that my HR was higher or lower during a session as a result of my average cadence during the session or other variables that can affect HR.
One thing I'm wondering about about: do calories calculated from power output include calories burned during that time due to other bodily processes? As noted above, it's necessary to use an efficiency factor of 20 - 25% when converting power into calories. (i.e., 20 - 25% of the calories went to mechanical power and 75% - 80% was lost as heat, etc.). Say you calculated 500 calories burned per hour based on power output, did your body just burn 500 calories during that hour, or was it 500 calories plus base metabolic rate, which for me is probably around 100 calories per hour for a total of 600. If I was able to add 100 calories per hour to what I calculate from power, and compared that to the Polar estimate, the Polar would still be high but not by a whole lot.
It's not necessarily about how many calories you eat that causes weight gain, but it's the type of calories you eat that will determine how much fat your body will gain. Different nutrients provoke different hormonal responses from your body and those hormonal responses determine how much fat you gain. Sugar is metabolised differently from fat and protein. A 2000 calories diet which consists of mostly fats, protein with low carbs will have a different effect on your body then a 2000 calorie diet of mostly sugars, refined carbs, with little protein.... Low-calorie starvation diets are dangerous in the long run because they put your body into "survival mode" and your body gets a signal to conserve as many calories as possible and store as much fat as possible to prevent starving itself to death.
Living a sedentary lifestyle is the worst. Exercise is the most important thing. OP needs to push himself and get active. Cycling, walking, running is ok but I think what OP needs is some serious weight training/strength/conditioning program.
If you sit at a desk all day you need to be more active more often. Being active once a day is better than not at all, but it's not going to do much to reverse weight gain. Go for a short walk in the morning, do at least 10-15 minutes at lunch, then ride in the evenings. Add those short periods of exercise right after you eat, never before. Also you need to eat more, better and more often. The farther you go into starvation mode, the more your body will resist by slowing down your metabolism. If you are eating 3 times a day, make it 4-5 times a day. Finally, eliminate the sugar, sugar substitutes and eat balanced meals (veggies, protein, complex carbs). Time spent counting calories is better spent preparing healthy meals and being active. I tend to think the coffee is a non-issue, unless you are drinking so much that you are chronically dehydrated.
Hmm, I have a Garmin Edge 510. As I said earlier, I'm 135 pounds. My Garmin estimates about 300-350 cal/hr for cycling at around 15 mph. That seems right to me, as in when I count calories & use the Garmin numbers, I lose weight as I would expect.
For OP at the same intensity of exercise but a higher body weight, that would be about 425 cal/hr.
I also ride my bike 10-14 hrs/wk, yoga 1 hr/wk, and swim 0-1 hr/wk. Maybe 1-2 hrs walking per week. So maybe 15 hrs exercise per week. Plus I don't have a desk job.
For me, there's only so far I can go with calorie restriction. Exercise is my only hope.