ptavv
07-30-2007, 02:00 PM
A bunch of the data that I post in this thread will be copy and pasted from other threads (where it was quoted from various books and physiology articles that I've read). It's also nothing that an adroit reader couldn't synthesize from what I've posted in the past, but it seems that unless I spell something out explicity (and even in spite of that) posters on this forum prefer to believe a bunch of ham headed fad diet ideas. Anyway, onward.
Here's a breakdown of when, and at what level, your muscles are engaging in particular types of respiration:
< 65% max HR gets you a 30-70 split between burning carbs/fat
65-85% max HR gets you a 50-50 split
85-88% max HR gets you a 60-40 split (carbs/fat)
88-95% max HR gets you a 70-30 split (carbs/fat)
90-100% max HR gets you an 80-20 split (carbs/fat)
> 100% max HR gets you a >90-<10 split (carbs/fat)
As I outlined here: http://www.tribalwar.com/forums/showthread.php?t=498746
It's important to not consider lower intensity workouts to be "better" for losing weight just because they tend to burn more fat. Absolute values are the important thing here, not the relative values of which fuel source is used. Burning more calories will always help you. That said, there is an optimal range in terms of increasing cardiovascular health (although it won't really improve your VO2max or respirtory capacity [you need HIIT for that by and large]). It's typically somewhere between 65 and 88% of your maximum heart rate. The upper end of this will be more beneficial than the bottom, but if it's not exercise you can sustain for at least an hour, then you should lower your intensity (that sentence only applies if weight loss is your goal! -- if you are training and looking to improve muscle endurance, respiratory capacity, or cardio capacity you should exercise at the maximal intensity you can sustain for any non-trivial period of time).
Okay, sorry that paragraph was so long, here's the layman's science explanation for why what I said above is the case.
As I've explained about a million times, the glycogen (carbohydrates) that your muscles use when you begin working out is stored in and around your muscles. This is called intramusclar glycogen. The other primary source of glycogen your body has is a reserve that's stored in the liver. Your central nervous system (CNS) requires glycogen to function, it can't burn fat, and your liver can't convert protein to glycogen fast enough to supply it (when exercising, at a resting metabolism it usually can), so your liver stores a bunch of glycogen.
When you begin working out your body will begin devouring the glycogen that's stored in your muscles. At around 70% max HR intensity, your body has between 60 and 90 minutes worth of fuel here. At the beginning of your workout, as the fatty acids that are floating around in your blood stream normally start to get depeleted, along with the glycogen in your muscles, your body sends you a signal that says, "RELEASE MORE FUEL."
When this happens there are two seperate processes that occur, your liver will begin to secrete more glucose into your blood stream to carry to the muscles. Your body will also begin to break down fatty deposits in order to get more fatty acids into the blood for your muscles to use. The longer you work out, the more your body will rely on the fatty acids that are getting released to fuel part of the workout. This is because, as muscle glycogen stores deplete, and your liver continues excreting glycogen, it'll hit a limit. Your liver is going to basically say, "You know, I can keep giving up this glycogen, but then his brain isn't going to have any fuel, so I'm just going to tell his muscles to get fucked and they can figure out another way to make the muscles work."
When this happens your body will mobilize even more fat, your maximal intensity will drop, and you'll experience "BONKING." Bonking sucks, you get a head ache, you get dizzy, you feel nauseous, in short, it sucks. The desire to avoid bonking is precisely why triathletes, marathoners, cyclists, all endurance athletes ingest tons of carbohydrates while exercising.
Bonking isn't going to help you lose weight, I'm bringing it up so that you can recognize the signs, understand why your body does that, hopefully listen to what it's trying to tell you, and not freak out. It's also important to realize I'm not telling you to work out to the point of bonking every time. Experiencing it is important in understanding your limits, and trying to avoid the experience again.
As your workout progresses (probably around the hour mark) if you're feeling a headache, or any of the other symptoms coming on, you should lessen your intensity. Now that we've burned up most of the glycogen that our body has lying around, we want our body to continue using up fat, until you run out of time for working out, get tired, whatever.
Okay, you're saying to yourself, that makes sense, but couldn't I take a short cut and just get rid of carbs in my diet so that I can skip that first half hour and go straight to burning fat? The short answer is no. The long answer is still no, and I mentioned many of the reasons in this thread: http://www.tribalwar.com/forums/showthread.php?t=498746
Another important reason not mentioned in that thread, is that by doing that you handicap your workout intensity. You simply won't be able to get decent intensities out of your beginning workout (remember the part about absolute caloric burn, rather than relative!!!). The second reason is more straightforward: You're training your body. If you force your body to adapt to having no carbohydrates around (because you won't give it any) and continue to exercise, your body will respond by stockpiling the available fuel it has, and making poor adaptations.
So, in addition to being unable to exercise at a high level, you're forcing your body to get used to needing to store fat, as well as forcing it to tear muscle apart in order to get glycogen for the left over muscles and the CNS.
Plus, by exercising healthily, you get into a good routine, habituate yourself and your body to healthy eating, you don't have to undergo shocks to your system when you "fall off the wagon" or reach your target weight. As well as the fact that you're habituating your body to exercising in a healthy and conducive way.
Sure, your weight loss will be less than the dumbass who is eating 55% fats, 35% protein, and 10% carbs for the first month, maybe even two or three. Two years down the road, he'll probably still be fat, and you'll be healthy.
Here's a breakdown of when, and at what level, your muscles are engaging in particular types of respiration:
< 65% max HR gets you a 30-70 split between burning carbs/fat
65-85% max HR gets you a 50-50 split
85-88% max HR gets you a 60-40 split (carbs/fat)
88-95% max HR gets you a 70-30 split (carbs/fat)
90-100% max HR gets you an 80-20 split (carbs/fat)
> 100% max HR gets you a >90-<10 split (carbs/fat)
As I outlined here: http://www.tribalwar.com/forums/showthread.php?t=498746
It's important to not consider lower intensity workouts to be "better" for losing weight just because they tend to burn more fat. Absolute values are the important thing here, not the relative values of which fuel source is used. Burning more calories will always help you. That said, there is an optimal range in terms of increasing cardiovascular health (although it won't really improve your VO2max or respirtory capacity [you need HIIT for that by and large]). It's typically somewhere between 65 and 88% of your maximum heart rate. The upper end of this will be more beneficial than the bottom, but if it's not exercise you can sustain for at least an hour, then you should lower your intensity (that sentence only applies if weight loss is your goal! -- if you are training and looking to improve muscle endurance, respiratory capacity, or cardio capacity you should exercise at the maximal intensity you can sustain for any non-trivial period of time).
Okay, sorry that paragraph was so long, here's the layman's science explanation for why what I said above is the case.
As I've explained about a million times, the glycogen (carbohydrates) that your muscles use when you begin working out is stored in and around your muscles. This is called intramusclar glycogen. The other primary source of glycogen your body has is a reserve that's stored in the liver. Your central nervous system (CNS) requires glycogen to function, it can't burn fat, and your liver can't convert protein to glycogen fast enough to supply it (when exercising, at a resting metabolism it usually can), so your liver stores a bunch of glycogen.
When you begin working out your body will begin devouring the glycogen that's stored in your muscles. At around 70% max HR intensity, your body has between 60 and 90 minutes worth of fuel here. At the beginning of your workout, as the fatty acids that are floating around in your blood stream normally start to get depeleted, along with the glycogen in your muscles, your body sends you a signal that says, "RELEASE MORE FUEL."
When this happens there are two seperate processes that occur, your liver will begin to secrete more glucose into your blood stream to carry to the muscles. Your body will also begin to break down fatty deposits in order to get more fatty acids into the blood for your muscles to use. The longer you work out, the more your body will rely on the fatty acids that are getting released to fuel part of the workout. This is because, as muscle glycogen stores deplete, and your liver continues excreting glycogen, it'll hit a limit. Your liver is going to basically say, "You know, I can keep giving up this glycogen, but then his brain isn't going to have any fuel, so I'm just going to tell his muscles to get fucked and they can figure out another way to make the muscles work."
When this happens your body will mobilize even more fat, your maximal intensity will drop, and you'll experience "BONKING." Bonking sucks, you get a head ache, you get dizzy, you feel nauseous, in short, it sucks. The desire to avoid bonking is precisely why triathletes, marathoners, cyclists, all endurance athletes ingest tons of carbohydrates while exercising.
Bonking isn't going to help you lose weight, I'm bringing it up so that you can recognize the signs, understand why your body does that, hopefully listen to what it's trying to tell you, and not freak out. It's also important to realize I'm not telling you to work out to the point of bonking every time. Experiencing it is important in understanding your limits, and trying to avoid the experience again.
As your workout progresses (probably around the hour mark) if you're feeling a headache, or any of the other symptoms coming on, you should lessen your intensity. Now that we've burned up most of the glycogen that our body has lying around, we want our body to continue using up fat, until you run out of time for working out, get tired, whatever.
Okay, you're saying to yourself, that makes sense, but couldn't I take a short cut and just get rid of carbs in my diet so that I can skip that first half hour and go straight to burning fat? The short answer is no. The long answer is still no, and I mentioned many of the reasons in this thread: http://www.tribalwar.com/forums/showthread.php?t=498746
Another important reason not mentioned in that thread, is that by doing that you handicap your workout intensity. You simply won't be able to get decent intensities out of your beginning workout (remember the part about absolute caloric burn, rather than relative!!!). The second reason is more straightforward: You're training your body. If you force your body to adapt to having no carbohydrates around (because you won't give it any) and continue to exercise, your body will respond by stockpiling the available fuel it has, and making poor adaptations.
So, in addition to being unable to exercise at a high level, you're forcing your body to get used to needing to store fat, as well as forcing it to tear muscle apart in order to get glycogen for the left over muscles and the CNS.
Plus, by exercising healthily, you get into a good routine, habituate yourself and your body to healthy eating, you don't have to undergo shocks to your system when you "fall off the wagon" or reach your target weight. As well as the fact that you're habituating your body to exercising in a healthy and conducive way.
Sure, your weight loss will be less than the dumbass who is eating 55% fats, 35% protein, and 10% carbs for the first month, maybe even two or three. Two years down the road, he'll probably still be fat, and you'll be healthy.