Training & Nutrition - I got ATL, CTL, TSB.... now... BMR, RMR, AMR... help

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04-24-07, 02:42 AM
Alrighty, so I'm trying to do a better job of managing the weight. I'm "hovering" around the 77kg mark, but want to stop "hovering" just above and get to hovering just above 75-76 kg so I don't wake up some mornings at 79kg. I dropped about 15 pounds over the winter base season as much as from eating more sensibly as from riding a lot more.

Anyway... I got the RMR measured (Cosmed Fitmate) and it's in the mid-1900's, which corresponds to all the typical calculators which show 1800's on the low side to 2100 (using the lean body mass calculators). I'm considering it to be right @ 1900 for round number usage.

I just want to confirm my calorie output formula.

Calorie output = BMR or RMR * Activity Factor + Exercise Calories?
Or is it just Calorie output = BMR + Exercise Calories

The difference is significant - assuming RMR of 1900 :

Calorie output = 1900 * 1.725 (activity factor, McArdle et al 1996) + 1800 kCal = 5077 kCal / Day
or
Calorie output = 1900 + 1800 = 3700 kCal / Day

(edited to add: yes, I average around 13500 kCal per week of expenditure on the bike)

Does the activity factor basically act as a "coverall" for people who aren't measuring calorie output in an objective method per day? If I were to aim for a 1 pound per week weight loss program (3500 calorie deficit per week), and shot for 3200 kCal per day intake when I should be shooting for 4500 intake, I'd eventually begin to suffer muscle mass depletion - no good. Likewise, Aiming for 4500 intake instead of 3200 intake would result in rapid weight gain.

I'm just concerned about is OVER estimating the calorie expenditure as well as UNDER estimating calorie requirements to continue positive fitness gains.

If I over estimate the calories, I'll undoubtedly begin to gain weight. If I under estimate, and cut to a healthy deficit amount, I'll actually be cutting too many calories out and end up suffering fitness loss.