Adult iron supplementation does not alter rota-rod motor endurance in YAC128 HD mice. Mice were maintained on special diets from 2–12 months of age. YAC128 HD groups performed significantly worse on the rota-rod compared to respective iron-dose wild-type mouse groups. Iron supplementation had no effect on performance. P-values: *p < 0.05, **p < 0.01, ***p < 0.001, n = 19–24.