Figure 4. Early age differences between frail/pre-frail and non-frail mice. Mice were identified as frail/pre-frail or non-frail based on the cut-off values of each criterion determined at 23 months of age. (A-F) summarize the performance differences in these mice at ages of 14, 17, 20 and 23 months. Values are presented as mean ± SEM. * indicates p<0.05 comparing frail/pre-frail to non-frail.