Why am I burning less calories?

[lapis]

Originally Posted by Kathryn

As your fitness improves, your HR for a specific activity will not get as high, and since that's what a HR monitor bases it's calorie burn calculations on, it will show a lower calorie burn.

I learned something quite interesting about HR at a racewalking clinic I attended: the standard "220-age" maximum HR calculation (which is what most heartrate monitors and gym equipment is based on) is off for most people. It was developed based on 50 non-exercising cardiac patients (and based on their peak HR during testing, NOT their actual max HR.)

We did lactate threshhold workouts to get a better estimate of our max HR. I'm 54, but for machines and my HR monitor, I have to put in 39, which is my max HR based on the 220-age calc. An 80-year-old guy who was there had to use 29 years old!

This is interesting to learn.

[jerebo]

Originally Posted by Kathryn

We did lactate threshhold workouts to get a better estimate of our max HR. I'm 54, but for machines and my HR monitor, I have to put in 39, which is my max HR based on the 220-age calc. An 80-year-old guy who was there had to use 29 years old!

Kathryn, I agree with Ella that you look like you're in your 30s!

I'm interested in how to do the lactate threshold workouts and how you figure out what number to enter in the HR monitors.

TIA

[Kathryn]

Originally Posted by ellaenchanted

Wow! You two are awesome!

Also, judging by your avatar, you look 39 to me.

Well, that's a very good pic of me...and it's been up for several years! (I need to get a more recent one, but I don't have any).

[susan p]

According to the 226 (for females) - age calculation, my maxHR should be 178. Which is interesting, since I have hit 193 before (under very extreme circumstances, during the Half-Wit Half Marathon in Reading PA.)

[Kathryn]

Originally Posted by jerebo

Kathryn, I agree with Ella that you look like you're in your 30s!

I'm interested in how to do the lactate threshold workouts and how you figure out what number to enter in the HR monitors.

TIA

For the anaerobic threshhold workouts, Dave McGovern (our coach) did the calculations, so I'm not sure how the whole calculation goes.

But we did 3, 8 minute intervals, with a 2-minute break between them.
He took our starting HR (after we did short acceleration walks), then noted out heartrate after every 2 minutes, and also 40 seconds (?) into the recovery. (if the recovery HR was too low, we were not going hard enough on the intervals: mine was 110, which he said was just where it should be).

This was to get us to our aerobic threshold HR. After about the third interval, our HR tended to peak and stay at that level (mine was 163). Then he somehow calculated our max HR based on that (mine is 181).

I recently found this site that has calculators for Max HR and anaerobic threshhold (when I filled in my max HR as per Dave's calculations, I got my anaerobic threshhold number as 90%):
http://www.runningtools.com/heartrat...htm#bepalingAt


HTH!

[stacydan]

Thanks so much for all your helpful advice and comments! I had the battery in the watch changed last year (had to send it off, which was a pain because it took FOREVER to get back!) but maybe the battery in the transmitter thingy is going? I know my cardio endurance has improved alot, but not enough for that huge difference!

I will check out the links on the heart rate calculations, that was really interesting information! And Kathryn, you do look in your 30's! you look great!

Stacy

[bzar]

Originally Posted by PeakFitness

When you weigh less you burn less calories.
As you get used to an activity, you get more efficient at it and wouldn't burn as many calories.
That's all I can think of.

^3. absolutely totally agree w/this.

another by-product of losing weight: you need less food than what you were accustomed to at the heavier weight.

congratulations on your success, by the way!

[bzar]

Originally Posted by Kathryn

I recently found this site that has calculators for Max HR and anaerobic threshhold

sally edwards is also a good resource (she has several books on heart zone training) in using a field test to figure out your AT. another way you can do this is watch your HRM and notate the highest HR seen in the particular sport. your AT for step aerobics is not necessarily the same as biking, for example.

[Sue B]

Originally Posted by stacydan

Thanks so much for all your helpful advice and comments! I had the battery in the watch changed last year (had to send it off, which was a pain because it took FOREVER to get back!) but maybe the battery in the transmitter thingy is going? I know my cardio endurance has improved alot, but not enough for that huge difference!

I agree with the others about weight and efficiency affecting calorie burn, but if your numbers took a sudden nose dive, it probably is the transmitter battery. My HRM does the same thing when it's dying - starts giving out much lower numbers than usual even though the "beats" match my heart. A jeweler may be able to replace the transmitter battery.

[Sophie]

still on the road and in haste, but must clarify:

yes, being more fit may mean more efficient - but more efficient at what? it doesn't necessarily mean burning less calories, because

1) more efficient at delivering blood to muscles (more blood pumped per stroke)
2) more efficient at extracting fuel from blood
3) more efficient at mobilizing stored fuels for use by body

which is why "more efficient" doesn't necessarily mean using up less calories during a workout. Add on variation in body size, work intensity, biomechanical efficiency (also important) bla bla - just saying you can't assume that more fitness =>more "efficiency" => less calories expended. Maybe yes, maybe no - as usual, it depends - bottom line, HRM is not always the best way to assess it.