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Ferdo
11-10-2003, 10:57 AM
Is it true that you need to have your heart rate at a certain rate to burn fat. IM kind of struck for time so I currently do my cardio 7 days a week 15 minutes three times a day on a recum bike. Will I burn the same amount of fat by doing it this way or should i switch to one session.

harryhoudini66
11-10-2003, 11:11 AM
I recommend looking in to HIIT if you are only doing about 15 minutes of cardio.

If I recall correctly I read a study that says you have to do cardio for at least 18 minutes. Also, the heart rate that you have to maintain consistency for this varies from person. For example, your weight and age will have an impact on this.

Midian
11-10-2003, 02:27 PM
cardio 7 days a week?? what's your goal ??

you do need to get your hart rate above 70% (i think) to burn fat

i'l look up the article for you

Midian
11-10-2003, 02:29 PM
here it is

http://www.bodybuilding.com/fun/matt62.htm

Saint Patrick
11-10-2003, 02:38 PM
Originally posted by Ferdo
7 days a week 15 minutes three times a day on a recum bike. Will I burn the same amount of fat by doing it this way or should i switch to one session.

If you're gonna use a bike, you're way better off doing it in one 45 min session.

aka23
11-10-2003, 03:42 PM
Originally posted by Midian
you do need to get your hart rate above 70% (i think) to burn fat

I disagree. You do not need to get your HR above 70% to burn fat. When your body is resting, the primary fuel source is usually fat. When you are reading this post, your primary fuel source is probably fat. And you are burning fat througout the low intensity cardio, whether or not your HR is above 70%.

As intensity decreases, a larger portion of fuel comes from fat. As intensity increases, calories are burned at a faster rate, so more total fat calories may be burned. Fat tends to be burned at the highest rate around 65-80% MHR, depending on many factors including previous training, genetics, and fuel stores.

For example walking a mile at 40% MHR would probably burn more fat than jogging a mile at 75% MHR. But walking 20 minutes at 40% MHR would probably burn less fat than jogging 20 minutes at 75% MHR, since more distance is covered in the jogging and more total calories are burned. One study found that the highest rate of fat burning occurred at 74%MHR (64% VO2Max).

These numbers apply to fat burning during the activity. If you are doing HIIT or other high-intensity cardio, then increased fat burning after the cardio is finished become more significant.

Midian
11-10-2003, 04:04 PM
Originally posted by aka23


I disagree. You do not need to get your HR above 70% to burn fat. When your body is resting, the primary fuel source is usually fat. When you are reading this post, your primary fuel source is probably fat. And you are burning fat througout the low intensity cardio, whether or not your HR is above 70%.

As intensity decreases, a larger portion of fuel comes from fat. As intensity increases, calories are burned at a faster rate, so more total fat calories may be burned. Fat tends to be burned at the highest rate around 65-80% MHR, depending on many factors including previous training, genetics, and fuel stores.

For example walking a mile at 40% MHR would probably burn more fat than jogging a mile at 75% MHR. But walking 20 minutes at 40% MHR would probably burn less fat than jogging 20 minutes at 75% MHR, since more distance is covered in the jogging and more total calories are burned. One study found that the highest rate of fat burning occurred at 74%MHR (64% VO2Max).

These numbers apply to fat burning during the activity. If you are doing HIIT or other high-intensity cardio, then increased fat burning after the cardio is finished become more significant.

you also need glucose ..........

http://www.bodybuilding.com/fun/matt62.htm

we have gone over this at BB.com, the most effective way is to be over 70% (part of the HIIT research) you even burn calls breathing, you always burn calls, but i'm talking about optimal use here, not wasting time

aka23
11-10-2003, 04:46 PM
Originally posted by Midian
you also need glucose ..........

http://www.bodybuilding.com/fun/matt62.htm

we have gone over this at BB.com, the most effective way is to be over 70% (part of the HIIT research) you even burn calls breathing, you always burn calls, but i'm talking about optimal use here, not wasting time

You also need glucose for what?

Aerobic exercise? Your body is almost always burning a mixture of fat and glucose/gylcogen. When at rest the average person gets about 65% of calories from fat and 35% of calories from glycogen/glucose. Your body also burns a mixture of glucose/glycogen and fat througout aerobic exrcise, regardless of intensity.

HIIT? HIIT involves sprints above your anaerobic/lactate threshold. During these sprints more than 99% of energy comes from non-fat sources, such as glucose/glycogen. However, your anaerobic/lactate threshold would be far above 70% of your MHR. My anaerobic threshold is approximately 90% MHR.

The article you referencing states "When you're doing cardio to burn fat, you want to stay in the range of 65%-70% of your maximum heart rate", which is not consistent with your posts about being above 70%MHR.

My point is, there is not a fat burning zone, and there is nothing magical about 70% MHR, 65% MHR, etc. The study at http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11782653&dopt=Abstract found the highest rate of fat burning near 74% MHR or 64% VO2 Max and within 10% of peak fat burning rate between 55 and 72% VO2Max. There was not a sudden drop off at a certain HR or VO2Max.