Calorie expenditure is unique per person as you would expect. One of the cheaper and more accurate ways to approximate how many calories you burned is to monitor your heart rate. I don't have any scientific proof to back this up, but my Polar heart-rate monitor and my bike's Garmin unit both measure calorie expenditure based on my heart rate. There is a formula that these devices apply to a few data points such as your maximum heart rate. HRmax, as it is more commonly known, is usually estimated based on age, but it can be determined experimentally. The formula also figures out which heart rate "zone" you are working in and applies a calorie burning rate for each zone. For example, my HRmax is approximately 190bpm, if my exercise was done at 160bpm I worked at about 85% HRmax. This percentage is one primary factor in the calculation, but other factors such as age, weight, and possibly even gender are also considered.
I have been monitoring my calorie expenditure using such a device (Garmin Edge) with a heart-rate monitor strap and I typically average about 1,000 calories an hour maintaining an average of 14mph and 160bpm. I am a 24 year old male weighing 193lbs. Here are links to some of my rides in the past few weeks which show all the details:connect.garmin.com/activity/395229connect.garmin.com/activity/592042connect.garmin.com/activity/615009
Your calorie rate estimated by SP seems a bit lower than I would expect but it probably isn't too far off. Perhaps my calorie burning rate is more rapid because I am somewhat new to road cycling. Another obvious reason is because I have been averaging a very low cadence. I realize that I need to bring this up from my current average of 70rpm to at least 80rpm to in order to salvage my knees in the long run.
You don't need an expensive cyclocomputer to get this kind of data, there are fairly inexpensive versions from vendors such as Cateye and Polar which can give you this information.
Even without this kind of data you should be able to lose weight fairly easily by cycling. A method I used prior to getting this equipment was just eating until I wasn't hungry. Sounds simple doesn't it? When making smart choices with food its pretty tough to intake too many calories when you cycle frequently. Plus remember that even while you are not exercising your metabolism will still be burning calories at a higher rate so your body will be ready for your next ride.
You could also monitor your body weight and waist measurement just to be extra sure that you have the right balance. Just make sure you look for trends rather than daily swings. After 20 mile rides my body weight has fluctuated as much as 8 lbs. I measure daily when I first get up in the morning just so I have consistent data points. In the past week I gained 6lbs even though I have been riding twice as frequently as I used to for a few weeks now. In the past few days I have already dropped 4 of the 6lbs. This is most likely explained by my heightened intake of food as well as muscle mass gain (remember I am new to road cycling).
Some people recommend only weighing in once a week but I feel that this can be even more misleading than weighing in daily. Remember your body can fluctuate in weight dramatically over a few days so if you happened to measure on a low point in week 1, but a high point in week 2 you could be mislead into thinking that you gained weight over the week. SP can graph your weight for you which is a pretty good way to find the actual trend. It will take at least a few weeks of measuring to get accurate results.
I got a little sidetracked there... now to answer your remaining questions.
To compensate for your calorie expenditure you should try to consume enough food to cover the calories burned within a few hours of the ride. Optimally you want to get at least half of the calories back as soon as possible, and the remaining half within the next few hours. If I understand your question correctly you said your normal calorie intake range is 1200-1550? If this is the case you will need to dramatically increase your intake if you plan to ride multiple times a week. Your body is constantly burning calories, especially when digesting food! If you burned 1250 calories and only eat 1550 then you have 350 calories left for your body just to survive. That is not enough to allow your body to recover in a healthy way and it will actually hurt your attempts at long term weight loss.
I quickly checked out my Resting Metabolic Rate (RMR) here, www.shapeup.org/interactive/rmr1.php
, but there are plenty of websites that can estimate this for you. It says I burn about 1,900 calories on a daily basis and this does not include my exercise! If I burn 5,000 calories a week cycling then I must eat 18,300 (1,900 * 7 + 5,000) calories a week or 2,614 calories per day just to maintain my current body weight. This calculation is actually lower than what I really need, because as I stated earlier an active body also burns more calories even at rest. I probably require about 2,900 calories per day to maintain my current weight.
You should use these tools and make sure you are not going too far negative or else you will start losing energy and motivation as your body starts to feel deprived of nutrition. I hope this helps!
| current weight: 174.0