Taken from the archives:
Hettinger, TW (1961) 'The Physiology of Strength' Charles Thomas. (pp
41-44).
------------
INFLUENCE OF VARIOUS FACTORS UPON TRAINABILITY
In muscle training experiments, one fact is very interesting to note.
The fact that training effect or, in other words, the speed in
increase of strength during a training session in the same subject
and the same muscle group-may be quite different in different
training periods. This fact made it difficult or even impossible to
compare the results of different training periods; especially, for
example, the different effects in increasing muscle strength by
different training methods. That compelled us always to use one
standard training method, one maximum isometric voluntary muscle
contraction from one to two seconds daily. The other results are
correlated with this standard test.
In trying to establish the reason for this different trainability, we
reviewed our training experiments of recent years, with a view to
identifying the month of the year during which experiments were
initiated. Then we assembled the training results obtained during
different seasons. During this period of five years, over 80 subjects
were trained with the same method, using for this purpose only the
arm muscle groups. The increase in muscle strength (relative to the
beginning value) during each month of the year was calculated for
each subject. The average increase in strength week by week in
percentage of beginning value for each subject during the whole year
was taken as 100%,
In Figure 9 the results in the average of all subjects are
demonstrated. In the abscissa the different months of the year are
indicated; in the ordinate, the training effect in percent, in the
way which we have described before. The lowest trainability was
observed during December, January and February-the winter months-with
a slight increase as spring came on. The highest trainability
occurred during the summer and autumn months, with a sharp drop in
trainability as winter set in.
In analyzing these results, we first connected the difference in the
results obtained with the fact that during summer and autumn the
greatest quantities of fresh fruits are available, resulting in the
highest intake of vitamins. This is the case in Germany, where these
studies were made, and it probably applies to all areas in the
northern temperate zone. In experiments, therefore, increased amounts
of vitamin C were prescribed for our subjects, both in the natural
form as fresh fruit and in the pharmaceutical form. But in no
instance did this hypervitaminosis C affect the trainability.
In this series of muscle training, vitamin D also was prescribed,
likewise without effect on the trainability. 116 It is of interest to
note that vitamin D had not only no effect on trainability, but when
vitamin D was given simultaneously with the ultraviolet radiation,
the effects of the latter - to be described presently - were
eliminated.
------------
Figure 9 Yearly variation in muscle trainability due to ultraviolet
radiation.
M C Siff Note: For anyone who is interested in reproducing the graph,
I used regression analysis to provide the following 6th order
polynomial equation for the northern hemisphere (Correlation
coefficient R = 0.9992):
Trainability Y = A0 + A1.X + A2.X^2 + ......... + A6.X^6
For the Southern Hemisphere, the graph begins with X = 1 = June and
ends with X = 12 = May Where X represents the month of the year
starting with January and the coefficients are:
A0 = 96.917
A1 = -108.2
A2 = 88.286
A3 = -30.03
A4 = 4.99
A5 = -0.38793
A6 = 0.0112
In tabular form, here are the values (trainability is given in
percentage variation when compared with the yearly average):
Jan 52
Feb 60
Mar 76
Apr 82
May 92
Jun 114
Jul 150
Aug 183
Sep 184
Oct 142
Nov 83
Dec 58
------------
We do not yet know why vitamin D eliminated the influence in
trainability of ultraviolet radiation, but had to accept this fact at
the moment without explanation. The positive effect derived from
vitamins C and D is well known, but it seems that this effect
operates only during a hypovitaminosis period.
A check through the literature brought out the fact that ultraviolet
radiation increases physical fitness. Therefore it seemed possible
that ultraviolet radiation might exert an influence on the increase
of muscle strength during training, and thus upon trainability
itself. It was also noted 19 that ultraviolet irradiation is lowest
in the wintertime, gradually increases through the spring months, and
is at its height during summer. The parallelism of these two facts in
relation to the season of the year, may be accidental.
In order to determine whether the effect of ultraviolet radiation was
the un known factor in our studies, we began a new series of training
experiments with male subjects in November and December; that means
(in middle Europe) during the winter months. During these weeks the
rate of trainability was found to coincide with that usually observed
during the wintertime. After a rest of several days during the year-
end holidays, in the first part of January the subjects were given
artificial ultraviolet once a week on the chest and the back until
erythema appeared (the skin became red). From radiation to radiation,
the intensity in time was increased about 20-25%. In all, six
radiations were given. During this time the muscles were trained
daily, with maximum isometric voluntary muscle contractions against
the resistance of a dynamometer. The muscle strength during these
radiation sessions increased at a greater speed than before. The
strength increase per week was practically double that before
radiation. The rate of increase in muscle strength during the period
of ultraviolet radiation was the same as that observed during summer
months.
The little figure on the left hand side in Figure 9 demonstrates the
fact that natural ultraviolet radiation and the artificial variety
give the same effect in trainability. The effect of ultraviolet on
the muscle and on the trainability of muscles, may be seen through
the adrenal glands. It may be that in this way sex hormones are
mobilised and that this change gives the measured effect. We do not
know enough yet about this problem, and can give only suppositions
about the relationship between ultraviolet and sex hormones,
primarily male sex hormones.
============
Jamie Carruthers
Wakefield, UK
http://groups.yahoo.com/mygroups
Sign all letters with full name & city of residence if you
wish them to be published!
Change settings via the Web (Yahoo! ID required)
Change settings via email: Switch delivery to Daily Digest | Switch format to Traditional
Visit Your Group | Yahoo! Groups Terms of Use | Unsubscribe
__,_._,___
Tidak ada komentar:
Posting Komentar