Exercise! (was: 8-bit man!)
Mon, 13 Jan 2003 16:49:36 -0500
At 09:17 PM 1/13/03 +0000, Russell Turpin wrote:
The more muscle you
>have, the more calories you metabolize even
>while sleeping, simply because muscle tissue is
>so much less "efficient" than fat in its own
even the average newbie to weight lifting can only gain about 3 lbs.
natural weight lifters work their asses off, after the newbie effect, to
actually gain muscle. it takes an entire yr. for instance, for the lucky
ones to put on five lbs. of muscle. the casual exerciser who is doing low
intensity cardio work is unlikely to putting in enough time with
progressive overload--making your workouts progressively more difficult--to
actually build muscle. one component of gaining muscle--just like gaining
cardio-vascular health--requires constantly pushing yourself to do a bit more.
what is happening is that, by working muscles more regularly, muscles are
recruiting more blood and water to nourish them and prepare them for the
next bout of activity. in which case, you burn more calories but it's not
because you've gained any significant amount of muscle cell tissue. most
trainers--good ones--will tell you that you can't gain muscle while losing
weight anyway since one condition requires a systematically catabolic state
and the other requires an anabolic state. that's why you see lifters put on
weight during the winter and cut during the summer. They try to put on fat
and muscle for a few months, then try to take off all the fat they gained
without losing the muscle--which is actually pretty hard to do. The body
likes to catabolize its own lean body mass when its systematically deprived
of calories and nutrition.
the latter is why people gain weight back after they lose it, too. Dieting
slows your metabolism and some people never really recover because, in
order to slow your metabolism, your body sheds LBM AND fat.
During weight training using progressive overload, proper nutrition, and
plenty of rest:
"2. The size of your muscle fibers increase, but that's not _new_ muscle
3. You may have grown more muscle cells from the newbie effect but, again,
that's about 3 lbs. Growth for a newbie starts about 6 weeks into training.
4. Your muscles recruit more water any time they encounter physical
activity that stresses them more than normal and is done repeatedly. (The
recruitment of water is what accounts for a weight gain for those sedentary
folks who first start out doing any exercise.)
During the first 12 wks of training, strength increases without
corresponding changes in the size of muscle fibers, although the muscle
fibers do begin to grow after 4-5 weeks. Still, _most_ of the changes that
you experience are the result of neural adaptations, centrally, and in the
muscle fibers themselves, peripherally. These adaptations improve your
ability to generate force. The changes in the first 12 weeks are mainly
neural adaptations that don't involve actual muscle cell growth or even
necessarily increased muscle fiber size. These changes can even account for
strength improvements for years.
Central neural adaptations include:
*) more recruitment of Type IIb fibers
*) an increase in signals sent to the muscle (increased 'rate coding')
*) a decrease in the activity of non-involved muscle (disinhibition)
(Flex the bicep. See it pop out _in contrast_ to the muscle you aren't using.)
*) improved synchronization among muscles involved in same movement
(Again, as pecs, delts, and triceps work together, they bulge out more)
In the first 12 weeks, most newbies will improve by between 10 and 40% if
they train each muscle group twice/wk.
Strength increases are due to these improvements in the nervous system and
from simply learning how to lift. When you first start out, you waste a lot
of energy just getting used to the act of lifting. Your muscles learn--they
adapt. Your nerves carry the message to the brain more quickly as you
continue lifting. Hence, strength increases are really about efficiency:
your nervous sytem is more efficient, you recuirt muscle fibers more
efficiently, your body stops working opposing muscles (and wasting energy).
All this is what constitutes "muscle fiber size increases" mentioned above.
No one actually knows the _exact_ stimuli behind muscle cell growth, but
these are the leading suspects:
1. high tension metabolic work (weight loads between 60-85% of 1RM (1
Repetition Maximum--you can lift and lower this weight with good form, but
couldn't lift any more than that))
2. eccentric muscle actions (walking down a hill is eccentric work and, as
you know, it's the action of lower the weight that is eccentric. lifting is
concentric. So, anyone who works hard at lifting the weight up, without
working on their form as they lower the weight, is not only risking injury,
but is also making inefficient use of the very activity that is as
important to growing muscles as is lifting.)
3. hormones: growth hormone, testosterone, cortisol, adreneline, nonadrendeline
"Once muscle growth is stimulated, the final requirement for growth to
actually occur is an excess of nutrients and energy (63). Reduced
calorie diets put the body in a systemically catabolic (tissue breakdown)
condition due to changes in hormone levels. Low-calorie diets cause
a decrease in growth promoting hormones such as insulin and thyroid
while increasing growth inhibiting hormones such as adrenaline, glucagon,
and cortisol (63). Similarly, overfeeding causes and increase in those
same hormones and an increase in lean body mass as well as fat (76). It is
generally impossible, except for beginners or those returning from a layoff,
for most individuals to gain muscle while losing fat at the same time.
Simply put, the body must either be systemically catabolic (for fat loss)
or systemically anabolic (for muscle gain). Attempting to gain significant
amounts of muscle while losing fat at the same time or vice versa tends
to minimize the results of either goal. Most individuals find that focusing
on either fat loss or muscle growth yields the best results. The [Cyclical
Ketogenic Diet] is somewhat unique among diets in that it couples a
catabolic phase (at below maintenance calories) with an anabolic phase
(at above maintenance calories), meaning that the potential to gain muscle
and lose fat simultaneously exists."
PROGRESSIVE OVERLOAD: THE ULTIMATE DETERMINANT OF GROWTH
<...> As long as stress continues to be applied to the body and muscles are
forced to work against progressively greater loads, assuming adequate
recovery and nutrients are provided, growth should occur in the long run.
Summary of training requirements for growth:
1. Use weights between 60-85% of maximum (roughly 6-20 reps)
2. Use a controlled eccentric (lowering) movement.
3. Apply proper progressive overload.
4. Supply adequate nutrients and allow adequate recovery
5. Train a muscle once every 4-7 days.
I stole all of the above from the exercise physiology section of _The
Ketogenic Diet_ from Lyle McDonald pp 210-213" </quote>