Table 3.

Skinned fiber mechanical properties

	Fmax, mN/mm2	EC50, μmol/L	Hill	n
EDL
HCR	339 ± 39	1.50 ± 0.023	2.47 ± 0.40	7
LCR	379 ± 45	1.62 ± 0.040*	2.62 ± 0.23	7
SOL
HCR	261 ± 41	1.05 ± 0.001	1.97 ± 0.13	8
LCR	253 ± 33	1.49 ± 0.002*	2.11 ± 0.23	8
SOL
HCR Fast	372 ± 69	1.29 ± 0.020	2.15 ± 0.12	3
HCR Slow	199 ± 34	0.91 ± 0.050	1.78 ± 0.20	5
LCR Fast	352 ± 69	1.65 ± 0.004	2.32 ± 0.28	3
LCR Slow	194 ± 21	1.37 ± 0.002	1.89 ± 0.25	5

Values are means ± SD; n, number of fibers. LCR, low capacity runners; HCR, high capacity runners; F_max, maximally developed tension normalized to cross-sectional area; EC₅₀, Ca²⁺ concentration required to develop 50% maximal tension; Hill, slope of the tension-Ca²⁺ plot. See Supplemental Fig. S1 for ANOVA analysis comparing Fast soleus (SOL), Slow SOL, and extensor digitorum longus (EDL) fiber mechanics (https://doi.org/10.35092/yhjc.11319998).

^*P < 0.05 LCR vs. HCR for EDL and SOL muscles by t test.