What question did this study set out to answer?

To investigate the effects of a 12-week endurance treadmill running program on left ventricular morphology and rectus femoris muscle fiber-type composition in rats.

January 1, 2001Open Access

Effect of endurance running on cardiac and skeletal muscle in rats.

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Why the study?

Does endurance running induce cardiac hypertrophy and alter skeletal muscle fiber composition in male Wistar rats?

Key Points

To investigate the effects of a 12-week endurance treadmill running program on left ventricular morphology and rectus femoris muscle fiber-type composition in rats.
Ten male Wistar rats completed treadmill endurance running six days per week for 12 weeks, compared with 10 sedentary controls (N=20).
Left ventricular wall dimensions and cavity areas were evaluated morphometrically, and rectus femoris fiber types were assessed histochemically for oxidative and glycolytic capacity.
Trained rats achieved a 40% higher endurance time, a 22% increase in left ventricular wall thickness, and a 25% enlargement in ventricular cavity size compared to controls (p<0.0001).
Endurance running significantly shifted fiber distribution by increasing Type I (24%), Type IIA (8%), and Type IIX (16%) oxidative fibers while reducing Type IIB glycolytic fibers by 20% (p<0.01).
Relative cross-sectional area increased for oxidative fibers and decreased for glycolytic fibers (p<0.0001), driven by hypertrophy across fiber types and transformation toward Type IIX oxidative-glycolytic fibers.

Structured PICO

Does endurance running induce cardiac hypertrophy and alter skeletal muscle fiber composition in male Wistar rats?

Population

20 male Wistar rats

Intervention

Endurance running on a treadmill 6 days per week for 12 weeks

Comparator

Sedentary controls

Outcome

Morphometric analysis of the left ventricle cross-sectional area, left ventricular wall, and left ventricular cavity, and semi-quantitative analysis of rectus femoris fiber-type compositionsurrogate

Endurance running in rats induces physiological cardiac hypertrophy and shifts skeletal muscle fibers toward an oxidative phenotype, suggesting potential benefits for preventing muscular atrophy.

Discussion

No takes yet. Share an insight, caveat, or question.

Implication

Extends rodent models of exercise adaptations; hypothesis-generating and should not yet change clinical practice.

Cite This Study

Díaz‐Herrera et al. (2001) studied this question.

synapsesocial.com/papers/6a83a6feb0b8dfdc4c62c9d4 https://doi.org/10.14670/hh-16.29

View Full Paper

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Effect of endurance running on cardiac and skeletal muscle in rats.

Key Points

Structured PICO

Discussion

Implication

Cite This Study

Effect of endurance running on cardiac and skeletal muscle in rats.

Key Points

Structured PICO

Discussion

Implication

Cite This Study

Also Consider

Also Consider