Having lost and kept off 125 pounds over the past 4 years I would like to make a few observations.

1. As has been mentioned, trying for a calorie deficit of in excess of 500 calories a day is unrealistic in the long term. Your body will very quickly go into starvation mode wherein in saves fat and starts burning muscle leading to not only feeling hungry but feeling lousy as well. It is far better to focus increasing your variety and level of activity, adding weights and resistance training to increase your lean muscle mass-remembering that muscle burns fat- and dropping your total fat intake to less than 25 %. No you will probably not lose 2 pounds a week every week but what you lose is more likely to stay lost, you will retrain your eating choices and your mind food set, and your general health should increase with the increased activity and decrease of in your diet and on your body.

2. I would not trust the computer programs that a mass produced data bases for calorie burn for activities. Especially in a semi passive non impact exercise like biking there are so many variables. Are you fit or not, how much weight are you moving, are you riding on the flat or hills, are you riding with a tailwind or a headwind, how much are you sweating, how hot is it, what is your metabolic rate, and how fast are you going?

For example, today I did a 70 miles charity ride at an average speed of 14.9 mph. In occasional glances at the speedometer I noted speeeds as low as 8 mph on the14% hills and 40 mph on the down hills The terrain was rolling with some pretty long steeper climbs. 25 miles of the ride was against the wind. The total in saddle time was 4 hours 45 minutes and I burned 1475 calories- I weigh 145 pounds now. At this point because I have trained in at distances above 55 miles, my average calorie burn is about 300 calories an hour. A year ago the same ride would have burne somewhere between 400-450 calories an hour when I weighed 160.

It's all relative.

3. I wear a monitoring device (bodybugg.com) recommended by a sports trainer/dietician that measures my skin temperature, pulse, and sweat % and works it against a logarithmic formula that includes ambient temperature to give me a calorie burn. It has a dieticians food data base that is extremely accurate for calorie content, as well as micronutrient breakdown of fat, protein, carbs etc. Between that and caliper measurements of body fat once a month as well as monthly body measurements, I think I am getting a pretty good breakdown of how much I burn, how much I eat, and where my weak spots are and what my trigger points are. There are several different types and brands out there. I just happen to have started with this one and like it.

4. It is a given point among most dieticians that people unintetionally underestimate their calorie input by 15-25%

5. It is also a sad fact that the machines at the gym are not accurate as far as cardio burn unless you are wearing a chest band, so if you are using a cardio workout as part of your resistance training, a good investment is a polar chest band. the one I use has a watch type monitor which can be preset for cardio rates and to beep or not when you drop below and various other features. (polar.com)

6. At my age, 61, my metabolism is probably slower and lower than that of a younger person. This means that I have to pretty much monitor everything I eat. It's all a matter of lifestyles I guess.

Anyway, yay for you for doing the ride, and good luck with your continued exploration of riding and weight loss. Take it day by day and if you ride, give yourself a small treat but keep it within your daily calorie limit or ride a few extra miles You're out there, you're hot and sweaty anyway, have your treat then ride another mile to keep the post ride burn going.

smooth roads and good tailwinds.

marni