Heart Rate

Does anyone have any good websites explaining why you need to stay in a target heart rate with cardio? I can't manage to get mine below 140 yet I'm supposed to be closer to 120. I don't see how that'd happen while I'm moving.

When running outdoors, mine will be anything from 150 to 180bpm.

The figrue of 120bpm is ideal if you are doing interval training. You do, say 400m and then walk or jog and when your heartbeat dips to 120bpm you do your next 400m etc.

Personally, there is no way I would be able to keep mine at 120bpm when running though.

The best heartrate for you to run at (for your age) for overall aerobic fitness and maximum burning of fat calories is around 140 to 150 bpm.

While you will burn a higher percentage of fat at 120 the overall calorie expenditure will be lower with less total fat burned.

At higher than 150 you will be building aerobic fitness less efficiently and will start burning predominantly sugar.

The whole fat burning zone is a myth, go for the gold and work it hard.

The whole fat burning zone is a myth, go for the gold and work it hard.

oh thats why she is asking. Yeah that is totally bogus. Get that HR up and keep it up for 20+ mins or do HIIT

The fat burning zone is a bit of a myth. Yes in this zone you burn a greater % of calories from fat BUT in the same time you will burn more total calories working a higher heart rate and this will give you greater weight/fat loss in the long run.

I.e. in the same time at a lower HR you might burn 200 calories with 60% of these being from fat (so 120 from fat) while at a higher intensity you might burn 300 calories with 45% of these being from fat (so 135).

So at a higher intensity in the same time you've burned more total calories and more caloreis from fat and you'll also improve your cardiovascular fitness.

Edited to add that you shouldn't get hung up on burning calories from fat anyway. The other main source that you burn calories from when exercising is carbohydrates. Nothing wrong with burning these off either. Remember it is essentially calories in vs calories out so focus on the total caloire burn for better weight loss

This page gives some good general info about burning calories, burning fat, etc.
http://www.revabsblog.com/2011/02/how-to-use-your-heart-rate-monitor-for-maximum-fat-burn/

What it does not say is where those other calorie burns come from at the higher intensity levels. It is my understanding (from my very limited research) that the calories burned which are not fat come mostly from carbohydrates and just a tiny bit from protein.

I am extremely out of shape and my cardio endurance is pathetic. Within three to five minutes of starting to exercise (brisk walking) I enter the aerobic zone.

Some people use an HRM to count their exercise calories (and one day I hope to do the same). Others use it to push themselves into certain exercise zones. I use mine to make sure that I don't exceed my limits and I hope to use it to find a good pace where I can increase my endurance without giving myself a heart attack. :-)