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15 Jan 2004

How much energy am I REALLY consuming?
I have a Polar heart rate monitor what I use religiously but I am uncertain how to calculate my TOTAL energy consumption for a day. -- Lets say I expend 300 kcal during an 1 hour exercise (as indicated by my polar watch) and my Base Metabilc Rate is 2,000 kcal - how much egenrgy did I consume that day ? (a) 300+2,000 = 2,300 or (b) 300+2,000/24*23? (deducting one hour of BMR as it may be included in one hour exercise consumption)

- Meaning does the kcal showed by the watch show how much energy was burned during the hour, or how much over and above the BMR?

Answer 392 views

01 Jan 0001

This is precisely the problem with energy measurement - even if the watch is 100% accurate (which is certainly is not), you can't ever know your basal metabolic rate without a real time-consuming way of having it measured. I'm not sure where you found this value, but it is probably very generalised. Also, BMR refers only to your metabolic rate in a resting state first thing in the morning before a meal. As soon as you eat, as soon as you walk up a flight of stairs, as soon as you do any activity during the day, it is affected (technically, it's no longer your BMR, because you're active). So, it really is a mission impossible and not one I would even say is worth it.

If you think about it, someone who remains at a stable weight over a period of just 10 years, is probably eating an average of 8 or 9 million calories during this period. In order to remain at the same weight, the body is somehow balancing this amount by using about 8 or 9 million calories too! So, it’s staggering that the body is able to do this as efficiently as this, and for this reason, being very particular about counting calories all the time is probably a lost cause. It’s also the reason why sudden crash diets, where you cut right back on eating and live on lettuce every day, for example, will not work. The body simply adjusts its metabolism and so you use fewer calories. This also promotes weight gain when you do eventually start eating again.

So, rather than taking drastic steps, you have to realize that slow and steady progress is the key. It is a useful idea to become educated about what you are putting into your body, and then to be sure that it’s not excessive. The general recommendation is that for a sedentary, inactive person, you should aim for about 29 calories per kilogram (A 70 kg person, for example, would need about 2000 Cal per day. In your case, because you are exercising, you might need up to 3000 a day - it's anyone's guess what the exact amount is).

I hope that this has helped a little – I have tried to just give you a general idea.
Good luck
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