Aims and objectives
The maintenance of skeletal muscle architecture is essential for contraction and performance.
In previous works we demonstrated that aerobic exercise changes skeletal muscle fiber type.
The arrangement of fibers within a muscle is an important architecture determinant of muscle’s mechanical function.
In pennate muscle fibers are oriented at an angle to the muscle’s line of action and rotate as they shorten,
becoming more oblique,
such that the fraction of force directed along the muscle’s line of action decreases through a contraction.
In penates muscle,
gear...
Methods and materials
Animal Treatment and Training
In this study male Wistar rats were used (200-250g).
The animals were divided into four groups: control and exercise.
During the study all animals were maintained in cages (2 to 3 per cage) under controlled temperature and humidity with food and water ad libitum.
The groups under the exercise programme performed an aerobic training for eight weeks.
The treadmill protocol starts with slow velocity and increase each week.
After the sixth weeks a 15° grade was introduced until the end of...
Results
The aerobic training show a slight increased of the type II fibers and similar decreases in type I in gastrocnemius muscle.
No changes were observed in penation angle,
muscle weight or on the thickness of the muscle.
Moreover,
no changes were observed in the ultrasound analysis.
Conclusion
Our results showed no changes in muscle architecture despite of the slight change in fiber type and an increase in the performance.
Thus,
the results suggested that there are no correlation between fiber changes and muscle architecture on the rat grastrocnemius.
References
Support: FCT,
Strategic Project (Ref: PEst-C/SAU/UI3282/2011),
and COMPETE