I'm a beginner at weight-lifting: I have been working out for 4 months now, and am definitely making improvements - am stronger (handle weights 2x to 3x more than what I started with), fitter (don't get out of breath as easily), and leaner (lost a couple of inches around the waist).
A key aspect of my motivation is to enjoy myself, and for me, this means understanding how things work - e.g. progressive resistance, muscle hypertrophy, fat loss, etc.
Unfortunately, a fair amount of information I find on the net tends to be mutually contradictory, and are often dogmatic pronunciations without really explaining why they are so. And, when some part of an article or publication contains dubious information, I have difficulty trusting the rest of it.
So, I have some "facts" collected from various places, together with my interpretation (which may be wrong - I am a beginner!), and hope the good folks here can help separate the truth from the myths:
1. On how your body uses fat / muscle
On Dr. Squat's Zigzag diet page (http://drsquat.com/articles/zigzag.html
), recommended elsewhere on this forum, I found:
There are 3500 calories in one pound of fat. That means that by reducing your food by 500 calories per day, you should lose one pound of fat per week, right?
Actually, much of the weight you'll lose will come from muscle tissue, NOT fat! Why? Because your body tends to use ("excess") muscle tissue for needed energy before it reclaims fat deposits.
As much as I have understood, fat storage is a strategy we (and other mammals and birds) have evolved for energy storage. So, I think its really odd then for our body to prefer to cannibalise muscle rather than tap into those fat reserves.
However, it does make sense that the body senses we are in starvation mode (when calorie intake is far below requirements) and tries to adapt by reducing expenditure (an economic analogy would be that if our income dropped, we could tap into our savings (fat), but would also try to reduce expenses (muscle, because they consume calories just by being there)).
I don't know if the breakdown of muscle releases energy or not (e.g. cutting some expenses can actually generate cash - e.g. selling the car instead of just stopping using it) but that's not really important to me: I don't want my muscles to atrophy!
It does however, make sense that we should exercise all the major muscle groups because that is effectively telling our body that those muscles are in use, so it cannot "save" by atrophying those muscles.
(plus, of course, exercising the muscles itself consumes calories, which helps create a surplus)
2. Do cardio in the morning before breakfast to burn more fat
(several sites, for example http://www.buildingbodies.ca/Cardio/ear ... rdio.shtml
The argument is that since you haven't eaten for a long time, glycogen levels in the body are lower, and therefore your body has to get more of its energy from fat.
So far, so good - but does it really matter if the energy you use in exercising comes from glycogen or fat? isn't it really the calorie deficit that counts? after all, what happens when you eat breakfast thereafter? any excess calories would go back to the fat deposits.
One of the most informative pages on energy systems I have found is this one - http://www.sport-fitness-advisor.com/energysystems.html
(and it reconfirms what I learned in high-school; that the only energy source muscles can use is ATP... anything else needs to be converted to ATP first)
According to this page, we can get energy from glycogen faster than from fat - so if we exercise on an empty stomach, the maximum intensity we can workout at will be limited to the rate at which we can get energy from fat. Which is not very ideal - if I am going to spend XX minutes on a workout, I don't want to be crippled while I'm doing it. So it would appear that working out before breakfast is actually counter productive.
(PS I do prefer to workout in the morning - because there's no chance of getting delayed at work messing up my schedule, and because I feel more alive during the day... but I do it after breakfast)
3. Simultaneous Anabolic / Catabolic processes (aka building muscle and burning fat simultaneously)
Building muscle is an anabolic process (using energy to bind molecules to make bigger molecules)
Fat loss is a catabolic process (releasing energy by breaking bigger molecules into smaller molecules)
So far, so good - all we've done is define (loosely) anabolism and catabolism.
But there are several resources that say you cannot do both at the same time - and that you body is either an anabolic state or a catabolic state.
Why must this be so?
After all, where do anabolic processes get their energy from, if not from catabolic processes? (breaking ATP down is also a catabolic process - if this ever stopped, we wouldn't be able to move our muscles?)
What then, is the origin of carb cycling, and alternating building and cutting? What is the magic that beginners have, that allows them to build muscle and burn fat at the same time? (e.g. see Stu's response here http://www.exrx.net/forum/viewtopic.php ... rb+cycling
Here's my understanding:
a. If we use progressive resistance training, our body tries to adapt by building up muscle (hypertrophy) - providing the building blocks (amino acids, energy, and whatever else is needed) is available, this will succeed
b. however, any excess resources (after basic metabolic needs, exercise, muscle hypertrophy) will be stored as fat (fat being the natural long term storage mechanism)
c. when you are serious about bodybuilding, finding that exact balance where you provide all the necessary stuff to build muscle, without any excess that would be stored as fat, is pretty much impossible. And it's better to err on the side of extra nutrients (so all that lifting results in maximum muscle growth) than less (which would mean the body can, at best, repair the muscle back to what it was)
d. but when you have this safety margin, then your fat level will increase... which someone serious about BB does not want. So, now you need to get into a calorie deficit to burn that off...
e. so why doesn't the body breakdown muscle as well (to "save" energy?) - I think it's because it takes some time for this reaction to kick in (your body knows that it isn't easy to build muscle, so it's not going to dispose of it lightly (to continue the economic analogy - things have to get pretty critical before you sell the car)... and before that, you move back to a building phase anyway
so, in summary, it's possible for anyone to build muscle and burn fat at the same time - but as your muscles get stronger and body fat percentages drop, it becomes more practical to separate the two goals than to try to find that exact balance of nutrients needed.