PDA

View Full Version : Cardio vs. Weight Loss?


Welcome to the Active Low-Carber Forums

Support for Atkins diet, Protein Power, Neanderthin (Paleo Diet), CAD/CALP, Dr. Bernstein Diabetes Solution and any other healthy low-carb diet or plan, all are welcome in our lowcarb community. Forget starvation and fad diets -- join the healthy eating crowd! You may register by clicking here, it's free!



shawn119
Fri, Nov-12-04, 22:36
I hope I can explain this in a way that's understandable. On the elliptical trainer I use, there are 2 heart rate target zones. The lower one is for "weight loss" and the higher rate is for "cardiovascular". My question is this. I can keep my heart rate far into the cardiovascular zone (around 150) without any pain or discomfort for a 45 minute workout. With my goal being losing weight in the most efficient and quickest manner, would I be better served staying in the lower zone for a longer workout, say an hour? Or would I be better served staying where I am. I'm a bit confused on this topic.

lilli
Fri, Nov-12-04, 22:45
I am confused about this too. I wouldn't see why one should work less than one can because of the guide on the machine. I mean, if you're dying at 150, that's another story. But if it's a good pace for you and you feel challenged but not like falling over, I think that's what you'd want to aim for.
Maybe the guide on the machine means that to start burning to lose weight, you need to AT LEAST get to the "weight loss" zone. I don't think working harder would mean you will only get cardiovascular benefits & won't lose weight, that's slightly ridiculous.

binki
Fri, Nov-12-04, 23:10
I think it's got to do with aerobic vs. anaerobic exercise, but don't know the specifics for sure.

Nudizzle
Sat, Nov-13-04, 21:58
stay in the lower zone to maximize fat burning and to reduce the possibility that you burn some lean mass to fuel your cardio workout.

also, an hour is probably more than enough. i'd keep it to no more than 40 mins at a time.

thank you, i'll be here all week. try the veal.

ttorres
Mon, Nov-15-04, 15:52
Several studies have shown high intensity interval training is the best for fat loss. Set your program to look like a high/lows graph (I i I i I i I i) with a fair amount of resistance. You should be working really hard at the high end, and recover during the low end.

MaryToU
Mon, Nov-15-04, 16:51
The way I look at it, to loss weight you want to at least get into the fat burning zone. But you will have better results all around both for your heart and weight loss doing the cardiovascular levels.

dina1957
Mon, Nov-15-04, 17:08
http://www.freeweightlosscenter.com/article48.htm

Daisy-Duke
Tue, Nov-23-04, 20:06
I agree with a lot of folks here the longer you can sustain your W/O at a lower level perhaps the longer time you are in that fat burning mode. Yet the High interval training is something that does wonders for me too. It is really hard becasue to are going to a really high level of exurtion (sorry about the spelling) and then down so fast only to turn around and continue this pattern. The time sure does fly though.

Good luck. I think what you are doing is great and if you have the extra time do a little more :D

Daisy :wave:

realdeal31
Sun, Dec-05-04, 10:28
Why not just listen to your body???? so much people are concerned about so little things.

Your goal is to lose weight so do your weight training at least 3 times a week and your cardio has much has you are confortable with. If one day you feel weak just skip the gym that day.

By working out this way you can modify your split, avoid overtraining and get better gains at the end.

Sometimes i take 3 days off from the gym and when i go back i find that i have gained strenght in all my lifts, or can do a bit more cardio.

WoodyAllen
Sat, Dec-11-04, 12:50
Well, you'll burn a lot more calories at the higher rate. In the 'fat loss' zone you just burn a higer percentage of fat than in the cardio zone.

So do the cardio to maximize fat loss. I actually find the 'fat burning zone' burns a piddling amount of total calories compared to when I go high intensity.

cbcb
Tue, Jan-11-05, 20:30
Just had a fancy test done at the doc's... in my case I'm at max fat burning at 100 bpm and hit the wall at 120 for fat-burning benefit, going into anaerobic. But that's just me.

cpriest
Mon, Aug-29-05, 20:19
Found this on the Precor website

Q. We have several workout machines in our office and I want to use them, but I'm confused about the different heart rate zones. What zone should I be training in to lose weight?

This is a great question that many people ask. It is important to realize that the body has two different fuels it converts to energy: carbohydrates and fats. The body burns these fuels in different proportions depending on your fitness and the intensity of your workout. Your body stores fewer carbohydrates than fat, yet it accesses the carbohydrates more easily. So the goal is to make your body more efficient at burning the stored fat while sparing the carbohydrates. Working out at higher heart rates will burn more carbohydrate calories in the short term, but it is working out in the lower zones that trains your body to become efficient at fat burning. In turn, this improves your endurance and aerobic fitness, eventually leading to a faster metabolic rate during exercise. This means that over time, you can burn as many calories at a low intensity as you were previously burning at a high intensity. With proper training this can happen in as little as three to six months.

Therefore, the best intensity for weight loss is one that seems 'fairly light' to 'somewhat hard'. Often people who cannot lose weight, or who even gain weight despite high intensity exercise and restrictive dieting, find success through a combination of slowing down their exercise, and improving the quality of their diet. This approach is not only more effective, but it's more fun and easier to stick to long-term!

-- Emily Cooper, M.D.

kbfunTH
Tue, Aug-30-05, 08:08
I think this whole 'cardio zone,' 'fat burning' zone is a bit misleading. Solve the equation for yourself and spend a few weeks working in both zones to see which one works better for you. I bet that most everyone will not notice a difference between the two in terms of fat loss.

I think too much energy is wasted on worrying about things like this.

cbcb
Tue, Aug-30-05, 08:32
I think this whole 'cardio zone,' 'fat burning' zone is a bit misleading. Solve the equation for yourself and spend a few weeks working in both zones to see which one works better for you. I bet that most everyone will not notice a difference between the two in terms of fat loss.

I think too much energy is wasted on worrying about things like this.

I appreciate the sentiment, but I for one do not wanna be exercising in such a way that it's going to do comparatively little good - am glad to know a little about the science behind how this works. :)

(I always knew I felt much better exercising at lower intensity for longer duration and just ran out of energy when I tried the higher intensity work that some thought was such a good idea. The test I took clearly showed why it wasn't.)

misskimbee
Tue, Aug-30-05, 09:41
To determine your fat-burning range:

(220-your age) x 65% =

(220-24 yrs.) x 65% = 127.4 should be my BPM to burn fat.

To determine aerobic threshold range:

(220-24) x 85% = 166.6 should be my BPM to work cardiovascular system.

kbfunTH
Tue, Aug-30-05, 09:52
I appreciate the sentiment, but I for one do not wanna be exercising in such a way that it's going to do comparatively little good - am glad to know a little about the science behind how this works. :)

(I always knew I felt much better exercising at lower intensity for longer duration and just ran out of energy when I tried the higher intensity work that some thought was such a good idea. The test I took clearly showed why it wasn't.)

What matters is that you are achieving your results. If that's what's happening, then no reason to change.

As for myself, I do a combination of both types of training.

UrbanZero
Tue, Aug-30-05, 23:40
I say shoot for the calories. I usually try to burn at least 300. So if I am walking, it may take an hour or running a half an hour.

But actually usually what I do is walk the turns and run the straightaways, interval training.

Usul001
Wed, Aug-31-05, 00:56
All of the above refernces to cardio zones fail to take into consideration the one element where most of us differ from the norm of the population. We don't have a stockpile of carbs to burn, and many of us don't even have very many free carbs floating around as blood sugar.

This means that choosing your level of intensity based on whether or not you want to burn fat or carbs is sort of a moot point. If you are in ketosis you are going to burn fat period, regardless of intensity level. However at higher intensity levels there may be some tendancies for the body to cannabalise muscle tissue to provide energy as well. Best way to make sure that doesn't happen is to make sure that you have plenty of protein before and after the workout.

Fat actually is a fairly efficient energy source once our bodies are used to using it fulltime.

So concentrate on what else you want to achieve - are you looking to increase your cardiovascular fitness? If so then you will need to work at a higher level of intensity, or cycle through a few levels with interval training.

However, if you are just after fat loss - the harder and longer you go - the more calories you will burn. As long as you are in ketosis, the majority of them should come from fat, due to the total lack of carbs in your body in the first place.

ValerieL
Wed, Aug-31-05, 08:47
I find it amusing that no one agrees on the best way, scientifically anyway, to maximise fat loss with cardio exercise. That blurb reprinted from Precor says lower intensity increases metabolism in the long run, the article lined by dina1957 says the higher intensity increases metabolism.

I can appreciate the the sentiment of wanting to know the best way, scientifically, to maximise workouts, but I'm with the guy that says just do what you enjoy most. I have tried over the years treadmill walking, recumbent biking, elliptical machines, walking outside, believing I had to go for long periods at lower intensities to do the "best" workout for fat loss. I hated it, always, it was boring and I never stuck with it. I took up running (jogging) last spring and I LOVE it! My boyfriend used to have to blast my butt to get me to go for a walk, and now I pester him to go for a run all the time. I run at a heart rate that is not low, more like moderate to high.

At this point, I don't care if I'm not maximising my workout. I'm working out regularly and loving it. And that's way better for me than working out haphazardly and hating every minute of it.

Val

Over40
Tue, Sep-20-05, 11:32
I think this whole 'cardio zone,' 'fat burning' zone is a bit misleading. Solve the equation for yourself and spend a few weeks working in both zones to see which one works better for you. I bet that most everyone will not notice a difference between the two in terms of fat loss.

I think too much energy is wasted on worrying about things like this.

In the past I have spent a lot of time jumping rope, Airdyning, jogging, etc. I have found no difference in weightloss during this time when compared to just doing resistance training. Three winters ago I lost quite a bit of weight while doing nothing but Nautiuls circuits three times a week and watching my carb intake.

In my experience the strength training aspect of weight loss is a bigger factor than the "cardio/fat burning" aspect.

Jon

DawninAus
Mon, Nov-28-05, 20:21
I have found that if i want to stay in the fat burning zone i have to be moving at a snails pace, and i dont see how that is helpful to me at all. I use the elliptical a lot and can do 30 mins with a heart rate of about 170bpm-180bpm. I have often wondered if this was good for fatloss or not.

kaypeeoh
Wed, Nov-30-05, 09:53
I think kbfunTH is right. Too many people are locked into the fat-burning-zone idea without understanding the logic behind it.

My understanding is you are burning a mix of fat and carbs all day long. While sleeping the heart rate is at its lowest and you are burning almost entirely fat. While rushing around during the day you have periods, like running to catch the bus, where you are burning almost entirely sugar. Anytime you are breathing hard, you're burning sugar.

The fat burning zone is where you are keeping your heart rate low enough that you are burning mostly fat. For a newbie, that could be 50% of max heart rate. For a highly trained endurance athlete, 90% of max heart rate could still be fat-burning.

So walking on a level treadmill is fat-burning. Walking three miles and hour it would take 15 hours to burn one pound of fat. If you are jogging 5 miles an hour you are still in the fat-burning zone so it would take about 9 hours to burn one pound of fat.

For that elite athlete, he's still burning fat at 90% of max heart rate so it would take an hour or two to burn one pound of fat.

locarbbarb
Wed, Dec-21-05, 21:58
To revitalize a sleeping subject, this is what I found recently:

To lose FAT, one should exercise moderately for a longer period of time, rather than push hard for a shorter time. For example, if someone burns 200 cal in 30 min (at the high end of their Target Heart Rate), they are burning 50% stored body fat and 50% carbs. (100 cal of stored body fat and 100 cal of stored carbs)

If they take 60 min to burn 200 cal, they will use 80% fat and 20% carb, so that burns 160 cal of body fat and 40 cal. of stored carbs.

What I read said:
Any exercise seems better when it burns higher amounts of calories, as calories really do count for weight loss, however it is the calories used from fat that makes the difference. Remember there are 3500 calories in 1 pound of fat, so it is much better to be burning higher levels of body fat during each exercise.

The bottom line is that one should stay closer to the mid-to-lower end of one's Target Heart Rate to burn more fat.

144.......127.........110
85%......75%........65%

The above is according to the chart on my elliptical machine, for age 50 (I am 51).

This is from a workout website:
Zone 3 (70 - 80% of MHR) - This zone is the most effective for overall cardiovascular fitness and is often called the "aerobic zone" or "target heart rate zone". This is the optimal zone to workout in to increase your cardio-respitory capacity or the bodies ability to transport oxygenated blood to the muscle cells and carbon dioxide away from the cells. After a while you will be able to cover more distance during workouts in less time. Your body will burn less glucose and more stored fat as fuel thereby working more efficiently. This zone is also effective for increasing overall muscle strength.

According to this, my THR is 119 - 136 (70-80%) (around 128 - like my goal weight! Easy to remember! :) And this rate is quite strenuous enough for me at this time.

I hope this helps, rather than adds to the confusion.

dstartz
Wed, Jan-18-06, 02:02
Low intensity sessions to burn off fat (http://www.brianmac.demon.co.uk/fatburn.htm)
Brian Mackenzie (http://www.brianmac.demon.co.uk)

There are two key variables that we need to know:

1. Fatmax - the exercise intensity at which the highest rate of fat oxidation occurs
2. Fatmax zone - the range of exercise intensities in which the fat oxidation rates remain within 10% of Fatmax

Researchers from Birmingham University's Human Performance Laboratory attempted to pinpoint the exercise intensities at which fat metabolism is maximised in a study of 18 male endurance cyclists with a training background of at least three years. Their work found that the Fatmax Zone is between 68% and 79% MHR

Alternative research has suggested that when you cycle, swim, row or run at a modest intensity of only 50% VO2max (about 69% MHR), fat provides about 50% of the calories you need to keep going for the first hour or so. If you keep going after that, fat becomes even more generous, providing around 70% of the total energy after two hours and 80% or more if your work duration exceeds three hours. If you increase the intensity then the Fat contribution decreases - at 75% VO2max fat provides 33% of the energy.

Dodger
Wed, Jan-18-06, 10:28
Be aware that all the tests done to determine fat burning percentages were done on people who eat lots of carbs. Their results are not what low-carbers can expect. Without the high-carb intake, your body will be burning a higher percentage of fat at every level.

I have found that I can exercise for longer at higher intensities than I could when I ate lots of carbs (and ate/drank carbs while exercising). Once your body has adjusted to low carbing, it becomes a fat-burning machine at all levels of exercise.

dstartz
Wed, Jan-18-06, 11:29
What you're missing here is that the body will start looking for glucose in the muscles (or worse yet consuming the muscles themselves) to burn instead of fat.

Dodger
Wed, Jan-18-06, 14:40
What you're missing here is that the body will start looking for glucose in the muscles (or worse yet consuming the muscles themselves) to burn instead of fat.Please explain. Unless it is starving, the body will not use muscles for energy.

dstartz
Wed, Jan-18-06, 15:01
If the body starts needing to use something other than fat as a fuel source and there are no 'carbs' to fuel that extra need then the body starts digging around for an additonal fuel source...
fat provides about 50% of the calories you need to keep going for the first hour or soThat's why working out at a lower HR is better for losing fat - the body's need for NRG is slow enough that "about 50%" of it can be delivered from fat.

At a higher HR the immediate NRG need is greater and the body can't convert fat to NRG fast enough ("If you cycle along at 75% VO2max, fat would provide 33% of the required calories (http://www.brianmac.demon.co.uk/fatburn.htm)") thus it starts looking for additional fuel sources at a greater rate than a 'Fat Burning' HR.

If there isn't enough glycogen/quick fuel to meet the need, where does the body get it's 'quick fuel' from?

Dodger
Wed, Jan-18-06, 15:56
Ketones can be burned instead of glucose for many body energy requirements. Thjs along with the increased ability to use fat for enegy is why low-carbers can do endurance exercise and not need the steady intake of carbs that others do. For example (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=6865776&dopt=Abstract):
These results indicate that aerobic endurance exercise by well-trained cyclists was not compromised by four weeks of ketosis. This was accomplished by a dramatic physiologic adaptation that conserved limited carbohydrate stores (both glucose and muscle glycogen) and made fat the predominant muscle substrate at this submaximal power level.

and It appears that endurance athletes can adapt to high-fat diets without any detrimental effect on physical capacity. from R. Brown, C. Cox, A. Goulding, High-carbohydrate versus high-fat diets: effect on body composition in trained cyclists, Med Sci Sports Exerc 32(3): 690-694 (2000)

dstartz
Wed, Jan-18-06, 16:34
lowcarb.ca (http://www.lowcarb.ca/tips/tips011.html): Ketones...are produced by the liver from fatty acids, which result from the breakdown of body fat in response to the absence of glucose/sugar.That accounts for the fat part of your NRG needs.

What about the carb/'fast fuel' part of your needs?
Exercise Intensity & Energy Source (http://www.brianmac.demon.co.uk/esource.htm): Energy is primarily supplied from two sources:

* Carbohydrates - in the form of glycogen stored in the muscles
* Fat - stored around the body

During exercise we use a combination of these energy sources. At a high intensity the main source of energy is carbohydrate and at a low intensity, fat is the predominate source.

The relationship between exercise intensity (% of your Maximum Heart Rate) and the energy source (carbohydrate and fat) is as follows:

% MHR__% Carbo__% Fat
65 to 70____40______60
70 to 75____50______50
75 to 80____65______35
80 to 85____80______20
85 to 90____90______10
90 to 95____95______5
100_______100______0

Carbohydrates, fat and protein all play a part in energy metabolism

kaypeeoh
Wed, Jan-18-06, 16:50
The relationship between exercise intensity (% of your Maximum Heart Rate) and the energy source (carbohydrate and fat) is as follows:

% MHR__% Carbo__% Fat
65 to 70____40______60
70 to 75____50______50
75 to 80____65______35
80 to 85____80______20
85 to 90____90______10
90 to 95____95______5
100_______100______0


I didn't realise at low heart rates that the body was burning 40% carbs. I always thought at low heart rates the body was burning fat almost entirely. This suggests in ketosis, where the body has no glycogen stores, that the body cannot function at upper heart rates. It explains why my ability to run suffers if I don't have carbohydrates on board.

dstartz
Wed, Jan-18-06, 17:25
When in college I studied 'Feeds & Feeding'. Since I was a weightlifter, swimmer and long distance cyclist at the time I easily translated the information I got in that class into what I was trying to accomplish in my exercising.

I was also raising out a batch of yearling ewe lambs at the time and in my inexperience bred them too early in their lives. It was the biggest lesson in protein catabolism I ever got...
Amino Acids & Bodybuilding (http://www.getbig.com/articles/protein.htm): The human body has the innate ability to break down muscle tissue for use as an energy source during heavy exercise. This muscle catabolism can cause muscle soreness, shrinkage of muscle tissue and may even lead to injury.

This enemy to bodybuilders is part of a process known as gluconeogenosis, which means producing or generating glucose from noncarbohydrate sources. The part of this reaction that of importance to bodybuilders is known as the glucose - alanine cycle, in which BCAAs are stripped from the muscle tissue and parts of them are converted to the amino acid alanine, which is transported to the liver and converted into glucose. Bodybuilding.com (http://www.bodybuilding.com/fun/glen13.htm): Walberg et al showed that when energy levels were reduced there was a corresponding increase in protein requirements for the same activity levels. This is logical as when you reduce your overall energy levels your body will try to find energy else where rather than tap into its stores...As such it converts protein into energy through gluconeogenosis.

dstartz
Wed, Jan-18-06, 18:04
The trick to all of this is 2 fold:

1) The body needs to be trained to burn fat for it's NRG needs. For the average everyday person just doing some form of exercise, their bodies need to be trained starting in the 'Fat Burning' zone (60-70%) and slowly brought up to the 'Aerobic' and possibly 'Anaerobic' zones. (Just like a cyclist that is coming back from an extended break. The first thing they need to do is work on rebuilding the capaillaries in their legs for maximum muscle oxygenation during riding. That's best done by simple walking exercises.)

2) Replace the protein used for NRG within the first half hour after training, which is when the body is most able to rebuild that type of damage. The caveat to this is that it needs to be a bioavaiable protein to be of most value.
Amino Acids & Bodybuilding (http://www.getbig.com/articles/protein.htm): The key is the window of opportunity that occurs immediately after exercise, when the muscle is especially receptive to nutrients and the blood flow to the exercised muscles remains high. The solution to optimizing recovery and growth in this case could include eating a small meal composed of protein with both simple and complex carbohydrates.

...a high protein meal won't put significant levels of amino acids into your bloodstream until a couple of hours after you eat it, especially if blood flow to the gastrointestinal tract has been diminished by a hard training session. The bottom line: Even if you eat the right foods soon after training, the nutrients will arrive at the muscle too late to take full advantage of the window of opportunity. ...

The value of free-form amino acids is first and foremost that they don't require digestion...They are free of chemical bonds to other molecules and so move quickly through the stomach and into the small intestine, where they're rapidly absorbed into the bloodstream.

Upon absorption, amino acids are processed by the liver. When you eat a steak, for example, only relatively few amino acids escape the metabolic actions of the liver. Yet the liver can process only so many at one time, and taking a dose of 3-4 grams of rapidly absorbed amino acids exceeds the liver's capacity, resulting in the aminos being directed to the tissues that require them, such as muscle in the case of bodybuilder recovering from training. Thus, the concept of 'directed amino acids'.

Dodger
Wed, Jan-18-06, 21:55
The relationship between exercise intensity (% of your Maximum Heart Rate) and the energy source (carbohydrate and fat) is as follows:

% MHR__% Carbo__% Fat
65 to 70____40______60
70 to 75____50______50
75 to 80____65______35
80 to 85____80______20
85 to 90____90______10
90 to 95____95______5
100_______100______0
Tables are nice, but sometimes the data does not apply.

The percentage of energy from fat varies not only with intensity of exercise but with amount of training and diet composition.

Get a copy of "The regulation of carbohydrate and fat metabolism during and after exercise." by John O. Holloszy, Wendy M. Kohrt and Polly A. Hansen of the Department of Medicine, Washington University School of Medicine; abstract here. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9740552&dopt=Abstract)

Figure 1 in the paper shows the difference in fat burning percentage between untrained individuals and endurance trained people. The trained peoples glucose percentage is 10 to 15% lower at any given intensity.

Figure 2 shows the difference in fat burning percentage between those on a high carb diet and those on a high fat diet. The high carbers show increasing glucose requirement as the intensity of exercise increases. (approximately 70% carb oxidation at 70% V02Max). The high fat dieters shows a constant carb oxidation percentage at all levels of exercise. That level is only 40%.

According to the paper The mechanism responsible for the improvement in endurance appears to be a high fat diet induced increase in mitochondrial enzymes, particularly those involved in fatty acid oxidation, in skeletal muscle

In the paper "Fat utilization during exercise: adaptation to a fat-rich diet increases utilization of plasma fatty acids and very low density lipoprotein-triacylglycerol in humans (http://jp.physoc.org/cgi/content/full/537/3/1009)" the conclusion is In conclusion, in this study we have demonstrated that VLDL-TG made a significant contribution to fuel utilization during exercise after adaptation to a fat-rich diet. The increased total fat oxidation observed after fat diet adaptation originated from both a higher plasma FA oxidation and utilization of VLDL-TG, and thus circulating VLDL-TG should be included among the lipid fuels that may be utilized during exercise. In contrast, the carbohydrate sparing observed after fat diet adaptation was due to muscle glycogen sparing and not to a diminished plasma glucose uptake.

As most exercise data has been taken on high carb eaters, it is misleading to apply the results to low carbers.

dstartz
Thu, Jan-19-06, 04:16
Dodger: The percentage of energy from fat varies not only with intensity of exercise but with amount of training and diet composition.dstartz:
% MHR__% Carbo__% Fat
65 to 70____40______60
70 to 75____50______50
75 to 80____65______35
80 to 85____80______20
85 to 90____90______10
90 to 95____95______5
100_______100______0

1) The body needs to be trained to burn fat for it's NRG needs...Dodger: Figure 1 in the paper shows the difference in fat burning percentage between untrained individuals and endurance trained people. The trained peoples glucose percentage is 10 to 15% lower at any given intensity.dstartz: 1) The body needs to be trained to burn fat for it's NRG needs...
This appears to be the only real difference in what we're each saying...Dodger: The high fat dieters shows a constant carb oxidation percentage at all levels of exercise. That level is only 40%.But, once again, the body needs to be trained for it...

Bookery
Thu, Jan-19-06, 16:29
The "burning a higher percentage of fat" = "burning more fat overall" equivalence seems to be a pretty persistent fallacy. While it is certainly true and amply demonstrated that our bodies burn more fat (as a percentage of total calories) at a lower intensity than at a very high intensity, people don't seem to take into account the fact that you just plain burn more calories at higher intensities. Essentially, it comes down to exercising in the most efficient manner.

For example (and I'm not trying to pick on you, locarbbarb, this is a topic that trips up tons of people):

if someone burns 200 cal in 30 min (at the high end of their Target Heart Rate), they are burning 50% stored body fat and 50% carbs. (100 cal of stored body fat and 100 cal of stored carbs). If they take 60 min to burn 200 cal, they will use 80% fat and 20% carb, so that burns 160 cal of body fat and 40 cal. of stored carbs.

If you spent that sixty minutes at a high intensity, you would burn 400 calories; 50 percent of that would be bodyfat, so you would burn 200 calories' worth of body fat.

In other words, you could get the same benefit of the low-intensity 60 minutes in about 45 minutes -- except not only would you have burned the same amount of fat, you would also have burned about 1.5 times the calories.

Now, in terms of effectivity, cardio interval training seems to be the best: Tremblay's 1994 study on interval training (Tremblay et al; Metabolism 43: 814-818 (1994)), showed that small amounts of interval training were greatly superior in terms of fat loss to much longer periods of low-intensity cardio — up to nine times more effective at reducing subcutaneous body fat. Cardio interval training is basically just running (or whatever) at a very high intensity for a short period of time (anywhere from ten seconds to a minute), then walking for a couple of minutes until you're pretty close to fully recovered, then running again.

Unfortunately, I don't have any information on how any of this changes with a fat-burning metabolism; I will leave that up to the other amply capable hands in this thread.

kaypeeoh
Thu, Jan-19-06, 17:02
My guess is the short bouts of extreme exercise stimulates Growth Hormone, which acts like an anabolic steroid. Another theory is that myglobin, which stores oxygen, is depleted rapidly and oxidizes fat to replenish. I got that from Body For Life.

eyesofblue
Thu, Jan-19-06, 17:35
2) Replace the protein used for NRG within the first half hour after training, which is when the body is most able to rebuild that type of damage. The caveat to this is that it needs to be a bioavaiable protein to be of most value.


What is a bioavaiable protien? Do you have examples?

mrfreddy
Fri, Jan-20-06, 16:53
I like the advice I read in the book "younger next year", something along these lines:

level one (beginners) work up to 45 minutes a day, six days a week, low intensity aerobic exercise

level two (after a few months of level one, how long depends on your condition, age, inclination, etc) - , low intensity aerobics 4 days a week, weight training, two days a week.

level three - do low intensity aerobics 2 days a week, mix in high intensity anaerobic tranining 2 days a week (working at a higher effort level, 70 to 80% of your max I think, adding some sprint work in there as well - hitting it all out for some short spurts. Wt. training 2 - 3 days a week.

the most important thing, btw, probably far more important than your effort level, is that you do it six days a week, without fail.

the big idea behind all of this is to reverse your bodies natural inclination to decay (after a certain age) with various chemicals that send growth signals to your body... the book goes way more into detail, of course, that's just my quickie thumbnail version...

Groovegirl
Sat, Jan-21-06, 09:29
Do interval workouts 2-3 times a week (get around your 85% MHR threshold) and do a medium intesty level workout 2-3 time a week.