peer review fitness myths

[Guest guest]

peer review fitness myths

> Supertrainers,

> After the discussion on this list regarding myths, I have decided to put

> together an article that I will add to my website. I would like to have

you

> all peer review it and point my inaccuracies. In addition, if you would

like

> to add some of your own, in the same format as below, I will give you full

> credit and add it to the article. Here is what I have so far:

>

> Myth #1:

> You can shape a muscle.

> The Truth:

> Your muscle shape is determined by genetics. You can make a muscle bigger,

> but you cannot shape a muscle. In technical terms, the way that dendrites

> innervate a muscle (in series), it is impossible to only contract a

certain

> part of the muscle. Therefore, the whole muscle contracts as a system.

>

> Myth #2:

> If I lift weights I will become muscle bound! I usually hear this one from

> women.

> The Truth:

> If it was so easy to become muscle bound, then why isn't everyone in the

gym

> muscle bound? It is not an easy feat to become muscle bound, and it

usually

> requires the use of anabolic steroids. The truth is that there is not

better

> way to become toned and leaner than using weights. So forget the aerobics

> classes and lift weights.

>

I disagree with this one. Not the main " myth " part, but the part about

" there is not a better way to become toned and leaner than using weights " .

I see this stuff all the time in weights related newsgroups, discussion

lists, etc.

ly I don't think there is a best way to get toned (realizing that toned

means visible musculature with low bf) and leaner.

For lots of people, a combined program of running and swimming will be more

enjoyable, keep the weight off, give the person a great physique, and be

more interesting and fulfilling than weights. Running can allow one to view

some great scenery, experience the runner's high,. keep weight off etc.

Swimming, especially open ocean swimming, offers fantastic marine life, etc.

So, while it is great when we, in the weights world, clap each other on the

backs and think we have discovered " the true path " , I don't think weight

training is a better solution, or the best. For becoming " toned and

leaner " , there are a lot of ways to the same goal. In Hawaii, for example,

bodysurfing (and I'm talking REAL waves, not knee slappers) is fantastic

exercise. It promotes explosiveness, it is a full body exercise done with

flippers (which you need to catch bigger waves, generally), it also promotes

cardiovascular fitness, coordination, timing, there is great scenery in and

outside the ocean, etc.

So, let's not overstate the issue when it comes to weight training.

Whitney Richtmyer

Seattle, WA

[Guest guest]

>Myth #1:

>You can shape a muscle.

The Truth:

Your muscle shape is determined by genetics. You can make a muscle

bigger, but you cannot shape a muscle. In technical terms, the way

that dendrites innervate a muscle (in series), it is impossible to

only contract a certain part of the muscle. Therefore, the whole

muscle contracts as a system.

** We discussed this in previous posts and I'm not sure but just to

play the devil's advocate here are some reviews of material that

suggest otherwise:

Electromyographic data indicate that there is selective

recruitment of different regions of a muscle that can be altered,

depending on the type of exercise performed. Whether such differences

in EMG activity ultimately lead to regional differences in muscle

hypertrophy is an empirical question. Some research suggests such

specificity in adaptations.

argues that, " an individual muscle is more than just

a collection of muscle fibers spanning the entire muscle belly with a

single muscle–nerve interaction. Instead, a muscle can be divided

into neuromuscular compartments, which are distinct regions of a

muscle, each of which is innervated by an individual nerve branch and

therefore contains motor unit territories with a unique set of

characteristics. In other words, different portions of a muscle may

be called into play depending on the task demands of the situation. "

Even if full recruitment and activation of all fibers eventualy

occurs during a given exercise as fatigue occurs, regional

hypertrophy may still occur as different regions may be

stimulated/fatigued to different degrees. This may explain some of

the adaptation specificities seen in many studies.

Another author argues similarly:

" Specially grouped motor units may also be involved in movement-

specific strength adaptations. Motor units in many upper body muscles

are grouped as sub-populations or `functional compartments'

based on the likelihood of their activation during a given

contraction (Ter Haar Romeny et al., 1982; 1984; Theeuwen et al.,

1994; Tonndorf & Hannam, 1994; Van Zuylen et al., 1988). Little

research has described compartmentalisation of lower limb muscles

although fibres of the gracilis (Schwarzacher, 1959), sartorius

(Barrett, 1962; Schwarzacher, 1959) and the semitendinosus (Barrett,

1962) have been shown not to run the entire muscle length. This

suggests that a similar `compartment-based' organisation to

upper body muscles may be present in lower body muscles in humans.

While the functional significance of compartments has not been

studied extensively in humans, there has been considerable research

on animal muscles(Chanaud et al., 1991; Pratt et al., 1991). Chanaud

et al. (1991) showed that the cat biceps femoris and tensor fasciae

latae were comprised of functional compartments with differential

synaptic inputs. Also, Loeb et al. (1987) measured the EMG evoked by

stimulation of the branches of the motor axon to the cat sartorius

muscle and found that each compartment was selectively activated.

Together, these two studies suggest that compartmentalised

muscles may in fact be comprised of small, uniquely-activated

musclets. Zuurbier and Huijing (1993) then discovered that fibres

located in different regions of the rat gastrocnemius medialis

reached their optimum (length at which maximum contractile force is

produced) and slack (length at which no passive/elastic force is

produced) lengths at different overall muscle lengths. This suggested

that innervation of compartments may be dependent on fibre lengths,

or at least the lengths of sarcomeres constituting the fibres.

Indeed, Van Zuylen et al. (1988) also found that the recruitment of

compartments within the human biceps brachii was dependent on the

joint angle, and therefore the muscle length, at which the

contraction was performed. "

.... " Indeed motor units of some longer muscles are not randomly

distributed throughout a muscle and are not equally likely to be

recruited, but are grouped as sub-populations or `functional

compartments'based on the likelihood of their activation during a

given contraction (Segal, 1992). For example, the biceps brachii

appears to contain a group of motor units that are readily recruited

during arm flexion but a separate group that are readily recruited

during forearm supination (Ter Haar Romeny et al., 1982;

1984;Theeuwen et al., 1994; Van Zuylen et al., 1988). Such

compartmentalisation has also been shown in muscles such as the human

masseter (Tonndorf & Hannam, 1994) and cat lateral gastrocnemius

(English & Weeks, 1984).

Further evidence that selective activation

of compartments can increase thenumber of sarcomeres in a region of

muscle has been provided by studies showing selective hypertrophy of

certain regions of muscle. Narici et al.(1989) found that hypertrophy

of the quadriceps was greater in vastus medialis and vastus

intermedius than rectus femoris and vastus lateralis after isokinetic

strength training. Furthermore, Housh et al. (1992) reported

significant increases in vastus lateralis and vastus intermedius

cross-sectional area at the mid-level and in rectus femoris across

the entire muscle following isokinetic strength training. In the

present study, there was evidence that hypertrophy of parts of vastus

lateralis and rectus femoris differed depending on the training

performed by subjects.

Therefore, continued selective recruitment of muscles and sections of

188 muscles may result in selective hypertrophy of these regions.

Given that muscle hypertrophy is at least partly attributable to

increases in the number of sarcomeres (Alway et al., 1989; Gollnick

et al., 1981; McDonnagh & Davies, 1984), increases in the number of

those sarcomeres at optimum length might occur in certain regions of

muscle with RT. Therefore, the recruitment of motor units within a

muscle seems not only contingent on the `size principle'

(Milner-Brown et al., 1973), type of contraction (Person & Kudina,

1970) and sensory input (Garnett & s, 1981; Grimby & Hannerz,

1974; Romanguére et al., 1992) but on their spatial location

within the muscle.

It is likely then that the recruitment of

functional compartments is related to the length of sarcomeres in the

muscle fibres. Van Zuylen et al. (1988) found that the recruitment of

these compartments was dependent on the joint angle, and therefore

the muscle length, at which a contraction was performed. Indeed,

Herring et al. (1984) found that sarcomere lengths varied between

different locations in the pig medial pterygoid, masseter and

temporalis muscles. It is therefore possible that functional

compartments are organised on the basis of the length-tension

relationships of a fibre's constituent sarcomeres. Strength

training using a particular movement pattern or joint angle could

stimulate changes in sarcomere length within the functional

compartment which was most readily recruited for a given

contraction. "

>Myth #4:

Slow lifting is safer than fast lifting, or ballistic exercises are

dangerous!

The Truth:

Most injuries when weight lifting are caused by improper form. Slow

lifting can be just as dangerous as fast tempo lifting. Think about

maxing out, is the weight moving fast or slow? Of course the weight

is moving slow. Even jogging is very ballistic, and everything you do

in life is ballistic. The truth is, ballistic lifting is required for

certain types of adaptation and elicits a completely different

neuromuscular response than slow lifting.

** Here is an argument against this position.

In a slow controlled action, a movement may be continuously

controlled by sensory input from the moving bodyparts with motor

commands adjusted by comparing the current with intended position, as

in the feedback servomechanism of a guided missile.

On the other hand,in a ballistic action, a voluntary movement

involves a largely preprogrammed command chunk, in which case it has

to run its full course without the(or very little) possibility of

current modification. This latter situation would be roughly like

that of a projected missile after the trigger has been pulled.

Given this scenario, should something go wrong, which of the two

actions allow for greater modification? For example, when an

anticipated load is unexpectedly decreased or increased, the

ballistic commands cannot be reduced or cancelled to the same degree

as slower commands. If this is accurate or a fair analogy, then

arguably, all other things being equal, slow lifting is safer than fast lifting.

[This sort of feedback safety control is based largely on the a theory of

linearity of

reflexive and other biological processses, which often have been shown to

be described better by NLD (nonlinear dynamics) theory. Thus, unheralded

'catastrophes' with no warnings of something " going wrong " can easily happen

during

slow movement, as well, as is regularly reported clinically. We cannot state

categorically than any given speed of activity is inherently safer or riskier

than others. Mel Siff]

Gus Karageorgos

Toronto, Canada

[Guest guest]

Whitney,

I think we may have different definitions of muscle tone. I am using the

definition from the ISSA text book which states:

Muscle Tone - The degree of tension and vigor in a gross muscle. Muscle tone

is increased through weight training, which results in a greater number of

muscle fiber " firing " while at rest.

Does anyone have any studies or information on fat loss with aerobics vs.

resistance training? Another supertrainer wrote the following article on the

subject which may be of some interest to the group:

http://www.wsu.edu/~strength/hiit.htm

Whitney thanks for taking the time to point out possible flaws. I don't want

to do an article on myths and then create some of my own. What do you think

of the response when using the above definition?

Thanks,

Bob Forney

San Mateo, Ca

> >

>

>I disagree with this one. Not the main " myth " part, but the part about

> " there is not a better way to become toned and leaner than using weights " .

>

>I see this stuff all the time in weights related newsgroups, discussion

>lists, etc.

>

>ly I don't think there is a best way to get toned (realizing that

>toned

>means visible musculature with low bf) and leaner.

>

>For lots of people, a combined program of running and swimming will be more

>enjoyable, keep the weight off, give the person a great physique, and be

>more interesting and fulfilling than weights. Running can allow one to view

>some great scenery, experience the runner's high,. keep weight off etc.

>Swimming, especially open ocean swimming, offers fantastic marine life,

>etc.

>

>So, while it is great when we, in the weights world, clap each other on the

>backs and think we have discovered " the true path " , I don't think weight

>training is a better solution, or the best. For becoming " toned and

>leaner " , there are a lot of ways to the same goal. In Hawaii, for example,

>bodysurfing (and I'm talking REAL waves, not knee slappers) is fantastic

>exercise. It promotes explosiveness, it is a full body exercise done with

>flippers (which you need to catch bigger waves, generally), it also

>promotes

>cardiovascular fitness, coordination, timing, there is great scenery in and

>outside the ocean, etc.

>

>So, let's not overstate the issue when it comes to weight training.

>

>Whitney Richtmyer

>Seattle, WA

>

>

>

>

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[Guest guest]

From: Forney <bobage24@...>

> Whitney- I think we may have different definitions of muscle tone. I am using

the

> definition from the ISSA text book which states:

>

> Muscle Tone - The degree of tension and vigor in a gross muscle. Muscle tone

> is increased through weight training, which results in a greater number of

> muscle fiber " firing " while at rest.

>

> Does anyone have any studies or information on fat loss with aerobics vs.

> resistance training? Another supertrainer wrote the following article on the

> subject which may be of some interest to the group:

Making this into a aerobics vs. weights conflict is not the whole picture.

There are lots of sports and activities that don't use weights, that are

alternatives to

weights. That was my point. Many are not endurance based at all, or would not

fit the

classic definition of aerobics. It is not an either/or thing.

Whitney Richtmyer

Seattle WA

[Guest guest]

> Myth #1:

> You can shape a muscle.

> The Truth:

> Your muscle shape is determined by genetics. You can make a muscle bigger, but

you cannot shape a muscle. In technical

terms, the way that dendrites innervate a muscle (in series), it is impossible

to only contract a certain part of the

muscle. Therefore, the whole muscle contracts as a system.

> Myth #2:

<snip>

This one doesn't sound right. For example: I notice when I do bicep curls on

the preacher bench, I can really feel

it right ion the peak of my bicep (esp. if I concentrate the movement there).

So, it follows [in my layman's way of

thinking anyway] that if I did this a lot, then I wopuld develop that part of

the muscle. Or, am I just hitting a different

muscle (since I dont really know how many muscles are right there anyway).

Bob Mckee

Atlanta GA USA

Bobbler@...

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