Affiliations: [a] Department of Water Sports and Winter Sports, Faculty of Physical Education, Józef Piƚsudski University of Physical Education, Warsaw, Poland | [b] Department of Biomechanics, Faculty of Physical Education, Józef Piƚsudski University of Physical Education, Warsaw, Poland | [c] Department of Biochemistry and Biology, Faculty of Physical Education, Józef Piƚsudski University of Physical Education, Warsaw, Poland
Correspondence:
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Corresponding author: Michaƚ Staniszewski, Faculty of Physical Education, Józef Piƚsudski University of Physical Education, 34 Marymoncka Str; P.O. Box 55, 00-968 Warsaw 45, Poland. Tel.: +48 501 08 09 43; Fax: +48 22 835 00 67; E-mail:michal.staniszewski@awf.edu.pl
Abstract:
BACKGROUND: Muscle strength depends among other factors on its
length, i.e., the angular position of the joint it spans. However, these
relationship is often neglected in the construction of training machines. OBJECTIVE: The aim of this study was to verify the effectiveness of
a variable-cam during strength training. METHODS: Thirty-two men divided into two groups participated in an
8-week intensive strength training of elbow flexors. One group (C) trained
on a machine with a cam developed in the shape corresponding to the strength
change characteristics of flexor muscles as a function of the angular
position in the elbow joint. The second group (D) trained on a machine with
a disc plate. The effects of the training were evaluated on the basis of
changes in the value of PT measured under isokinetic conditions,
anthropometric parameters, and CK activity. RESULTS: After the end of the training, a significant increase in
the values of the PT and anthropometric parameters were observed only in
group C. Weekly changes of CK activity appeared only in the group exercising
with a cam, while in the group exercising on the machine with a disc plate,
the two-day rest turned out to be too short for the elimination of the CK
molecules from the blood to occur. CONCLUSIONS: Strength training using a machine with a
muscle-specific adjusted cam is especially effective in the case of the
elbow flexors.
Keywords: Intensive training, biceps brachii, isokinetic muscle strength, CK activity
