End-stage conditions such as chronic heart failure (CHF) and chronic obstructive pulmonary disease (COPD) have shown some of the most dramatic increases in mortality in the developed world over the past 40 years. Both are therefore leading causes of morbidity and mortality worldwide and should be considered as a major economic and social burden that is both substantial and increasing. In these conditions, exercise therapy should play an integral part in maintaining the patient’s maximal level of independence and functioning, as well as slowing or possibly even stopping the progression of the condition. In this context the main objectives of these doctoral theses are: a. Proving the safety of different exercise modalities. b. Identifying the most effective exercise interventions in regards to clinical parameters. c. Proving the feasibility of outpatient rehabilitation programmes for these high risk populations. This work, therefore, combines three studies looking into the effects of non-pharmaceutical interventions – predominantly different exercise regimes in the two major conditions in the mortality statistics of CHF and COPD - both with a very poor prognosis. In conclusion it can be said that the results and experience of all three studies demonstrate the safe feasibility of different outpatient exercise interventions and suggest specific positive adaptations in patients with heart failure and COPD which also led to a lower hospitalisation rate. There are clear hints that the therapy spectrum could be supplemented significantly by specific training interventions. The financial implications for any health care system are also highly relevant.