Community-based group physical activity programs promote exercise opportunities for older people. The aim of this study was to examine the short-term, new participant effect after joining Vitality, a community-based group physical activity program available in the East of England for older adults. Two independent groups of participants were assessed before and after an 8 week period: a group recruited from the ‘Vitality’ program (VP) (n 15, age: Age = 69.4 ± 6.4 y), and; a non-intervention control (CON) group (n 14, age: 64.5 ± 5.8 y). Assessment outcomes included basic physical health measures, a fitness test battery, and three psychological scales. The VP group recorded statistically significant improvements on the following outcomes: body mass (VP: −1.39 kg/CON: −0.2 kg), body mass index (VP: −1.5 kg/CON: −0.2 kg), 6 min walk (VP: +42.81 m/CON: −0.45 m), 30 s sit-to-stand (VP: −1.7 s/CON: −0.7 s), the chair sit-and-reach (VP: +3.12 cm/CON: +1.90 cm), and the 30 s arm curl test (VP: + 2 reps/CON: +0.9 reps). No significant differences were found with the other outcomes assessed. New members to the Vitality program achieved several physical and functional benefits without regression on any aspects of physical or psychological health.