Calories...

[PamNY]

Over and over the rule of thumb has been eat to feel only 80% full.

Shootingstar, I've never heard that rule of thumb -- is it to lose weight?

Catrin, good luck. I admire your diligence. No expertise here, but my common sense says "try it for a while."

[OakLeaf]

It's a Japanese proverb (maxim?) - the way I understand it, it's meant for everyone, to eat the correct amount for good health.

I guess my main question for Catrin would also be the accuracy of your calorie expenditure calculations. Have you used a power meter to calibrate your HRM results, or done a calorimetry where they collect your breath on a treadmill or stationary bike? Calories can be converted to watt-hours, but without measuring something, whether it's your power output or your O₂/CO₂ exchange, estimates are about as accurate as estimating your maximum HR based on your age - that is, not very accurate at all.

[Catrin]

I am unsure how accurate my Polar HRM is where calories are concerned, but I do know that it shows I burn far less than, say, a year ago. I know it isn't exact, I use it as a rule of thumb. I use that in combination with how my body feels and what my blood sugar says. It has been a combination that works well.

[limewave]

Can someone help me out, I cannot figure out where the calculation for "Net Calories" comes from. I've tried googling it, and the explanations I've read I do not understand. I am TERRIBLE at math. What is the basic calculation?

I see the "net calories" on my dailyplate page, but I don't get where it comes from.

[Veronica]

It's the calories you end up with after you factor in the calories you burned through physical activity. I think.

It's not a number that I personally would want to use since I don't think any of the numbers you get from HRM or internet calculators are very accurate. Each human is SO different and we all respond differently to different activities.

But the important thing is to find what works for you.

Veronica

[Catrin]

It's the calories you end up with after you factor in the calories you burned through physical activity. I think.

It's not a number that I personally would want to use since I don't think any of the numbers you get from HRM or internet calculators are very accurate. Each human is SO different and we all respond differently to different activities.

But the important thing is to find what works for you.

Veronica

This was how my nutritionist explained it the other day. I do pay attention to it. It isn't exact, but it gives me a ballpark figure. I have to use some kind of metric,'especially on those days when I exercise or ride for multiple hours.

[limewave]

Okay, so if I'm understanding this correctly:

RMR is approx 1650 calories.
80 min run + 40 min yoga = 1000 calories burned
TOTAL 2650
I ate 1800 worth of food
Net calories are: 2650-1800 = 850

So, to reach the recommended 1200 Net calorie mark I should have eaten 1450 calories instead?

That doesn't seem to make sense to me. I'm showing my poor math skills.

*I agree that HRM overestimate calories burned, so I go with approx 80% of what my garmin tells me for calories burned during a workout.

[Miranda]

I am unsure how accurate my Polar HRM is where calories are concerned, but I do know that it shows I burn far less than, say, a year ago. I know it isn't exact, I use it as a rule of thumb. I use that in combination with how my body feels and what my blood sugar says. It has been a combination that works well.

Before I read this post, it was exactly what I was thinking in scanning your thread.

Have you re-set your HRM lately?

That's one of the things I check with my students in spin. If their weight has changed, re-set that. Plus, their fitness level. And diff types of exercise, impactive vs non-impactive, run diff heart rate efforts compared to perceived exersion.

The "stock numbers" in the HRM as usually set for 220 - ur age = Max HR... then the percentage of effort... which should match your perceived exersion... which from there gives you a total calories estimation burn.

As regular exercisers, we are generally fitter than the 220 - ur age theory. The fitter you become, the higher your threshold becomes.

Best way is to compare your perceived exersion with what that number should be for your HR percentage. You can take that number you see and work backwards to re-set Max HR.

For me, 220 - age42 = estimated Max HR 178. So, 75% max would be 178 x .75 = 133bpm. HOWEVER... say my Garmin stats when riding chatting w my partner outside... still working, but able to speak short sentence etc. (roughly endurance about 75% effort) is 155bpm. When I re-set my hrm, I took 155 divide by .75 = 206mhr.

Where my students get in trouble is that they leave the monitor settings, assume they are burning all these calories, keep eating them, and it's falsely high.

Sorry that's a long blab on... hope makes some sense, though.

[Catrin]

I reset the weight on my HRM periodically...I make certain that it is within 5 pounds of my current weight, and closer when I remember to check it. I remember when it told my I burned 700 calories for 80 minutes of spinning class, and now - for the same time period, I am lucky if it breaks 400...

Great example though, and a good illustration of why we need to be careful to reset it.

[Catrin]

My dietitian sent her final calorie recommendations to me last night, and she actually didn't change them overly much. She raised my non-ride day calorie budget to 1,600 and to aim for 2,200 on days I ride. Outside of the really long ride days, of course, where I can burn that many calories or more on the bike. Not to concerned about that, but more importantly she helped me nail down how I need to divide my carbs throughout the day. I am going to ask her for references regarding the 50% carbss recommendation. I will post any references she provides here.

She did provide other information that will be helpful, I will give her suggestions a shot.