Xcel and Crowler
Xcel,
Sounds about right given energy expenditure.
For those who are interested, basal metabolic rate (BMR) is your lowest resting metabolic rate (baseline), i.e., when you are very relaxed or asleep and motionless. Usually measured in the morning upon waking. Resting metabolic rate (RMR) is a more general term for met. rate at rest and is higher than BMR during the day, as your moderate levels of arousal increase energy expenditure even when you're sitting still.
Total energy expenditure is a matter of RMR throughout the day, energy cost of activity, thermic effect of activity (e.g., energy expended after you've exercise) and thermic effect of eating (energy expended d/t digestion, etc.). The last 2 are pretty minor and usually ignored.
HOWEVER - this gets a Crowler's point - resting metabolic rate can be greatly changed by energy balance. This is the idea of the set-point theory. If you overeat, your body increases metabolic rate to keep you at a lower bodyweight. The opposite when you diet for fat loss - metabolic rate is adjusted to conserve energy. The degree to which your body "defends" its set point (body mass and fat) is highly variable.
Some very interesting studies were done up in canada using twins, both fraternal (DNA similar, like siblings), and identical (same DNA). In the studies, RMR, BMR and daily energy expenditure were determined at the start and the subjects placed on a diet to match expenditure (they were sequestered in a clinic - nowhere to run, nowhere to hide). After a period to assess if they were in caloric balance (no changes in wt., etc.), they placed them on a diet that was:
Experiment #1.) 1000 kcal / day in excess, 6 out of 7 days a week for around 3 mo.
OR
Experiment #2.) 500 kcal / day in deficit, 6 out of 7 days a week, and required 500kcal of exercise (6 out of 7 days a week) for about 3 mo. (1000 kcal / day *deficit*, 6 /7 days per week.)
Afterwards, the range in weight gain (exp. 1) was like 5kg to 15kg - HUGE!!! Same caloric excess given initial energy needs but a GIGANTIC difference in how well the individuals' metabolisms adjusted to prevent weight gain. Same thing was seen in experiment #2, except the rate was in weight loss, of course.
Even cooler - the fraternal twins were pretty close when looked at in pairs - within 3-4 kg wt. gain (exp. 1) or loss (exp. 2). The identical twins were DEAD on in terms of wt. gain or loss (~1kg difference). Those with pretty similarly DNA (fraternal twins) responded very similarly. Those with identical DNA (identical twins) responded identically, within experimental error.
So, Crowler, it sounds like you've got a body that really desires to be lighter. I'm the same way - 5000 kcal / day offseason and I won't gain an ounce.
-Randy
P.S. The studies were done by Claude Bouchard - big guy in genetics of obesity research.
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