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. Author manuscript; available in PMC: 2008 Jan 28.
Published in final edited form as: Neuroscience. 2007 Aug 27;148(4):970–977. doi: 10.1016/j.neuroscience.2007.06.033

Table 7.

Effects of chronic overload on myofiber profiles of young adult and aged plantaris muscles.

Variable Young Control Young Overload Aged Control Aged Overload P value
Cross-sectional area (µm²)          
Fiber types combined 1966 ± 120 2306 ± 78* 1809 ± 95 2146 ± 70† 0.005
Type I 1756 ± 104 2097 ± 142†‡ 1554 ± 52 1858 ± 164‡ 0.03
Type II 1997 ± 126 2343 ± 76* 1861 ± 108 2188 ± 75† 0.009
Fiber type composition (%)          
Type I 13.4 ± 0.4 17.6 ± 0.4 15.4 ± 0.3 15.0 ± 0.5 0.38
Type II 86.6 ± 1.1 82.4 ± 1.4 84.6 ± 2.2 85.0 ± 2.4 0.40

Values are means ± SE.

*

indicates significant (P<0.05) difference from Young Control and Aged Control groups.

†

indicates significant (P<0.05) difference from Aged Control group.

‡

indicates trend (0.05 < P < 0.10) toward difference from controls of same age group.