Table 1. Impact of age on fiber type by tongue region.

The estimated marginal means of the percent muscle fibers positive for each myosin heavy chain type reported by age and region with the estimated standard error. Exercise and control group results are combined, as there was no significant age-region-exercise interaction.

Fiber Type	Age Group	Anterior	Middle	Posterior
MyHC IIb	Old	54.3±3.5%	14.3±1.5%	4.0±1.0%
	Young Adult	76.0±3.5%	21.0±1.5%	8.0±1.0%
		p < 0.001*	p = 0.004*	p = 0.009*
MyHC IIx	Old	41.9±3.5%	73.7±1.5%	75.2±1.7%
	Young Adult	22.9±3.5%	69.0±1.5%	80.3±1.7%
		p = 0.001*	p = 0.035*	p = 0.041*
MyHC IIa	Old	2.8±1.3%	21.2±1.0%	29.2±1.3%
	Young Adult	0.6±1.3%	1.3±1.0%	16.2±1.3%
		p = 0.235	p < 0.001*	p < 0.001*