According to Antonovsky, the sense of coherence (SOC) determines health and wellbeing. This life orientation is shaped up to the age of 30 and is supposed to remain constant up to senior age. In a field study, in which the SOC, psycho-social resources and subjective health were assessed at three points in time, it could be shown for the first time that the SOC in old age can be malleable and expanding. The master sample (time t(1)) consisted of N = 58 active and "healthy" seniors at the mean age of 66.3 years (65.5% female), who decided to take part in a 14-week program focusing on physical activity and/or self-reflection (endurance training, strength training, yoga, or meditation), respectively. One year before, 90% of them had participated in the Greifswald Aging Study (t0). The intervention study was attended regularly by n = 42 persons (t1 and t2). The SOC and associated health appraisals remained constant over a period of one year (t0-t1); re-test reliabilities varied from satisfactory to very good. Overall, the current SOC (t1) was more important than the past SOC (t0) in accounting for current well-being (t1). The intervention (t1-t2) revealed that the elderly's SOC was significantly strengthened-independently of the program they took part in. Correspondingly, participants' wellbeing, subjective health and psycho-social resources were enhanced. Taking part in a systematic, age-based and group-oriented program that encourages an active and productive every-day life brings about coherence-promoting and health-promoting life experiences in old age.