Frailty affects the quality of life of older age adults by limiting mobility, reducing physiological reserve and reducing independence. The frailty phenotype is typically characterised by exhaustion, loss or lack of physical activity, weight loss and weakness, although more recently there have been proposals to extend the frailty criteria to include physiological characteristics such as inflammation, oxidative stress and vascular function. Exercise has the potential to prevent, delay or even reverse frailty, but not all exercise is perceived as suitable for an older age population. The purpose of this study was to test Tai Chi and Zumba Gold® as exercise interventions in older age adults (65 to 75 years old) to improve characteristics related to the frailty phenotype. Muscle strength and flexibility (functional fitness as a measure of weakness), cardiorespiratory fitness, blood pressure, vascular function (FMD), markers of oxidative stress (total antioxidant capacity, malondialdehyde, 8-isoprostane, protein carbonyl), inflammation (CRP) and aspects of wellbeing related to exhaustion were assessed at baseline (pre-), 6 weeks (mid-) and 12 weeks (post-intervention). Both Tai Chi and Zumba Gold® improved systolic blood pressure, vascular function, and functional fitness following the 12 week intervention to a similar extent. Furthermore Antioxidant capacity was significantly increased (303 ± 15.56 vs. 336 ± 18.82 μm; p = 0.0028) and lipid oxidation significantly reduced (36.41 ± 6.4 vs 13.49 ± 2.5 pg/ml; p = 0.0042) after 12 weeks of Tai Chi compared to baseline. Anxiety, physical and mental fatigue decreased in both groups, with a greater decrease in mental fatigue in the Tai Chi group. Taken together, these changes suggest that Tai Chi has the potential to reduce outcomes related to the extended frailty phenotype in older age adults.