exercise - target heart rate to reduce body fat

shimmergal

I am confused about the target heart rate to burn fat. I generally tend to push myself and workout at target heart rate of 85%+ during my cardio training sessions. I want to burn more calories (400cals +/45 min session)

But I met a nutritionist who said that I was not doing it right. I was losing muscle and not fat by working out at such high heart rate.

How do you burn 500+ cals by working out at a lower heart rate ? please help

mistyb47711

I am confused about the target heart rate to burn fat. I generally tend to push myself and workout at target heart rate of 85%+ during my cardio training sessions. I want to burn more calories (400cals +/45 min session)

But I met a nutritionist who said that I was not doing it right. I was losing muscle and not fat by working out at such high heart rate.

How do you burn 500+ cals by working out at a lower heart rate ? please help

When I do my cardio I keep mine at 60 to 70 % and burn like crazy......I burn about 400 to 550 in 60 mins.

gbell4

A higher percentage of the calories burned will come from fat, rather than carbohydrates, when you exercise at a moderate steady pace. However, by doing high intensity cardio you will burn a lot more overall calories and end up burning more fat calories total, even though the percentage is lower. Does that make any sense? I may not be saying it very well. I'm sure others will chime in.

bjshooter

I don't get it either :S

My HRM is always beeping at me toslow down, I have a heart problem though and I can't get it down, does that mean I am going to struggle?

jimmy_jenkins

yeah gbell is correct. Heres some numbers that explain to it, even though ive completely made them up, just for an example.

60 min cardio at 60 % - 500 Calories burnt (400 fat calories (80%), 100 muscle calories (20 %))
60 min cardio at 80 % - 700 Calories burnt (525 fat calories (75 %), 175 muscle calories (25%))

shimmergal

yeah gbell is correct. Heres some numbers that explain to it, even though ive completely made them up, just for an example.

60 min cardio at 60 % - 500 Calories burnt (400 fat calories (80%), 100 muscle calories (20 %))
60 min cardio at 80 % - 700 Calories burnt (525 fat calories (75 %), 175 muscle calories (25%))

hmm...can I know how you arrived at the 80/20 versus 75/25 rule ? still not clear....

Azdak

This is becoming one of the most annoying things I hear when it comes to fitness.

There seems to be this mass hysteria taking place--either that or human physiology has just radically changed in the past year while I wasn't looking.

The fuel substrate you burn during exercise--whether it is carbohydrates, fat, or amino acids--has virtually no effect on body composition.

Depending mostly on the duration and intensity of a workout session, the body will utilize a different (and changing) mix of fuel substrates. It does that to meet the physical demands of the workout. During extended, higher intensity cardio workouts, the percentage of energy derived from amino acids can increase modestly.

Does that mean you are "burning muscle". No. No more than using fat as a fuel substrate means you are "burning" stored body fat. Exercise is a temporary condition. The body mobilizes the resources it needs to meet the work demands being imposed. Afterwards, as part of recovery, it works to restore homeostasis. Anything that was "used" is replenished.

There seems to be this persistent idea that if you use a gram of amino acid, first of all it comes directly out of a muscle cell, and, secondly, a giant vault door slams behind it and it can never be replaced. Amino acids are used for much more in the body than for muscles--it's not like there is a severe shortage under normal conditions. And even if it is true that amino acids are being used for fuel, we are talking about a tiny amount--burning 1000 calories in an hour might result in the use of 1 oz.

Does that sound like something worth worrying about?

Our metabolism is very dynamic. Catabolic (breaking down) and anabolic (building up) processes are occurring constantly. Whether the net effect of these processes is pushed in one direction or another depends on numerous factors--not just exercise. For the average person, the effects are too trivial to even think about.

The main downside to pounding away at longer duration, higher intensity workouts day after day is you diminish your ability to use fat as a fuel during exercise. This will likely not affect your weight loss, but it can ultimately impair your overall training. It's best to follow a balance approach that includes easy, long endurance day, the higher-intensity steady-state tempo days, and high intensity interval days. The workouts will work together to increase your fitness level, which will enhance your weight loss program as well.

Azdak

yeah gbell is correct. Heres some numbers that explain to it, even though ive completely made them up, just for an example.

60 min cardio at 60 % - 500 Calories burnt (400 fat calories (80%), 100 muscle calories (20 %))
60 min cardio at 80 % - 700 Calories burnt (525 fat calories (75 %), 175 muscle calories (25%))

hmm...can I know how you arrived at the 80/20 versus 75/25 rule ? still not clear....

"ive completely made them up" would seem to be the appropriate phrase here.

gbell4

Yeah I wouldn't be too worried about "burning muscle". If so do some strength training along with your cardio. And be careful of so called nutritionists as well. The regulations and standards for using that title are very inconsistant across the country. I'm not saying anyone who calls themself one is a total hack, but to know you're getting good information, a registered dietician is the title to look for and trust.

jimmy_jenkins

Managed to find an article I read ages ago on this.

http://exercise.about.com/od/weightloss/a/The-Truth-About-The-Fat-Burning-Zone.htm

shimmergal

This is becoming one of the most annoying things I hear when it comes to fitness.

There seems to be this mass hysteria taking place--either that or human physiology has just radically changed in the past year while I wasn't looking.

The fuel substrate you burn during exercise--whether it is carbohydrates, fat, or amino acids--has virtually no effect on body composition.

Depending mostly on the duration and intensity of a workout session, the body will utilize a different (and changing) mix of fuel substrates. It does that to meet the physical demands of the workout. During extended, higher intensity cardio workouts, the percentage of energy derived from amino acids can increase modestly.

Does that mean you are "burning muscle". No. No more than using fat as a fuel substrate means you are "burning" stored body fat. Exercise is a temporary condition. The body mobilizes the resources it needs to meet the work demands being imposed. Afterwards, as part of recovery, it works to restore homeostasis. Anything that was "used" is replenished.

There seems to be this persistent idea that if you use a gram of amino acid, first of all it comes directly out of a muscle cell, and, secondly, a giant vault door slams behind it and it can never be replaced. Amino acids are used for much more in the body than for muscles--it's not like there is a severe shortage under normal conditions. And even if it is true that amino acids are being used for fuel, we are talking about a tiny amount--burning 1000 calories in an hour might result in the use of 1 oz.

Does that sound like something worth worrying about?

Our metabolism is very dynamic. Catabolic (breaking down) and anabolic (building up) processes are occurring constantly. Whether the net effect of these processes is pushed in one direction or another depends on numerous factors--not just exercise. For the average person, the effects are too trivial to even think about.

The main downside to pounding away at longer duration, higher intensity workouts day after day is you diminish your ability to use fat as a fuel during exercise. This will likely not affect your weight loss, but it can ultimately impair your overall training. It's best to follow a balance approach that includes easy, long endurance day, the higher-intensity steady-state tempo days, and high intensity interval days. The workouts will work together to increase your fitness level, which will enhance your weight loss program as well.

thank you for throwing some light into this. In summary, I should do a mix of high interval training days, long endurance (at lower intensity), steady rate tempo days and build my strength. Thanks so much!

shimmergal

Yeah I wouldn't be too worried about "burning muscle". If so do some strength training along with your cardio. And be careful of so called nutritionists as well. The regulations and standards for using that title are very inconsistant across the country. I'm not saying anyone who calls themself one is a total hack, but to know you're getting good information, a registered dietician is the title to look for and trust.

agree. Thank you.

shimmergal

Managed to find an article I read ages ago on this.

http://exercise.about.com/od/weightloss/a/The-Truth-About-The-Fat-Burning-Zone.htm

Wow! that is interesting.. something for me to think about when I am working out....not much difference in terms of total fat cals burned. Looks like working at 70% should be good to shoot for on some days and 85% on certain days. Thanks for sharing the link.