kuan

I never knew how hard I was riding until I used my brand new Timex Ironman HRM today. 60-70% feels terribly slow, yet it's supposed to be the best for fat burning. I could stand to lose about 10lbs, but do I gain anything aerobic from exercising at such a low level?

Next question: If I have bigger muscles wouldn't that make it easier to move my bike? So if I build leg strength, would I find it easier to ride faster at a lower HR?

EricT

You will burn fat at that rate, but of course you have to do it for a long time. The idea with the slower heart rate is that you can do it longer, hence burning more total calories. And supposedly your body uses more fat for fuel at that range. But calories burned per hour is less than at a higher rate.

As you get more fit, you will be able to go faster at a lower HR. But it takes more than just leg strength. Your legs, heart, lungs, blood chemistry, muscle composition and other factors all contribute to your overall efficiency.

webist

60 - 70% of your real maximum is probably not all that slow or easy to pedal. HRM are set based on low averages to avoid hurting people. It is likely that your real max is a bit higher. You can find out with a stress test given by your doctor. Or, less formally, you could ride like a bat out of heck up a hill until you can't keep it up and check your monitor just before you collapse. I predict 60-70% of that number will be harder to pedal. Don't hurt yourself though. Medical supervision is always a good recommendation.

kuan

I'm 35, using 220-35 gives me 185.

60-70% is 129-148
70-80% is 148-166

But using the resting heartrate formula,

220 - (age 35) = 185
185 - (resting HR 59) = 126
126 * (intensity .70) = 88.2
88.2 + (resting HR 59) = 147.2

So this formula says 70% is 147, and 80% is 159 compared to 148-166 above?

Why is the top number off by so much and which should I use?

I'll try the bat out of hell method tomorrow if I can find a hill.

Edit, and 60% using the resting heartrate method is 134.6. Weird.

vindicator

Your math is wrong. 185 x .70 = 129, 185 x .60 = 111
your 60-70% range should be 111-129.

JavaMan

You will gain plenty! If you like to read, this is pretty good. It's based on a book by Dr. Phil Maffetone, who trained 6 time Ironman winner Mark Allen. (Mark Allen initially asked the same question - How can I gain anything from exercising at such a low level?)

https://www.teammudge.org/training/TrainingLogIntro2.pdf

operator

220 formula, might as well throw it out. It'd be more accurate if you did your own stress test.

Roody

If you are over 40 and sedentary, it would be a good idea to get the stress test before riding too much. And then you will have a more accurate approximation of your max HR.

Pat

Well, to put my oar into this one.....

When we exercise, we can burn either fat or carbohydrates (glycogen). Glycogen is fairly heavy and an inefficient way of storing energy so our stores are very limited about 2000-2500 calories.

The thing is that in burning glycogen, you generate twice the energy per oxygen molecule used over burning fat. So in circumstances where oxygen is limited such as in the muscles at hard exertion, your body will burn glycogen preferentially.

I have found that if I go out and do a hard ride with a fast group that when I get back I am completely ravenous. If I go out and do a ride at a more sedate pace, I come back with an appetite but I am not famished. I believe the difference is that under the hard exertion, I have greatly reduced my glycogen stores and my body wants to replace them right now.

Also our society tends to push a "no pain, no gain" approach to exercise. Less intense forms of exercise have their place too.

va_cyclist

60-70% is an "easy/recovery" pace. You might burn a higher percentage of calories from fat at low intensity, but the overall volume of calories burnt will be higher at higher intensities, and along with that, more fat as well. (Your highest percentage of calories from fat burns while you are asleep!)

velocity

WORD!

kuan

OK I printed and read the teammudge at breakfast. I believe it, all of it, at least the general principle of going slow and what it can do for you. I'm going to do it.

I'm off to the bookstore tonight.

Thanks all, you've all been a great help.

Doctor Morbius

Agree.


Kuan, the 220 formula is a statistical average for large cross sections of a population. Individual max heart rates can vary by as much as 15 beats per minute above or below the 220 - AGE results. Some people may even vary by as much as 20 BPM.

The 220 - AGE would have my MHR at a paltry 175 BPM. However, I've had it tested at 191 BPM.

Suggest you have a stress test done.

Doctor Morbius

Yup. Sitting on the couch watching TV is good for fat burning too.


Kuan, the fat burning zone is an exercise myth. There are many that persist BEYOND ALL REASON!! You'll no doubt read quite a few of them on this forum.

JavaMan

Yes, the fat burning zone is a myth. But so is burning fat watching TV, according to Dr. Maffetone. Unless you stimulate your aerobic system by easy exercise, your body will use glycogen for almost everything, including watching TV and sleeping. The book I just read is "The Maffetone Method". The guy is kind of ecclectric, but he makes sense, and then there's the Mark Allen factor...

kuan

Guys, I know you all have different opinions and you all probably know what works best for you, and I really appreciate all the help. It looks like I have two choices.

1) Find my max aerobic heartrate and subtract 10 to find my zone

or

2) Find my max heartrate and use a percentage.

Can a personal trainer do either for me?

Old Gammy Leg

I'm fairly new to using an HRM, and also found 60-70% ridiculously slow - like I wasn't putting in any effort whatsover.

I'm 26, so my max HR should be (220 - 26) = 194. However, riding as hard as possible up a nightmare hill I saw 210 on my HRM. I can believe that, because I normally ride at 170-180 and don't feel like I'm going anaerobic.

Is it normal or even possible to have such a high max HR, or could the HRM be faulty (Polar F5)??