Most testing and training studies make objective measurements of responses to exercise by means of a wide range of physiological parameters of varying degrees of sophistication. However, rarely do such studies take as their central theme how the individual feels in response to a test or to exercise, before and after training. Some studies even conclude that a period of training has had no measurable effects on their subjects because the range of measurements made before and after training was unchanged -yet the subjects report that they felt better and could cope with exercise more effectively. Thus, the aim of this thesis is to describe a series of studies which examined the physiological responses to exercise of middle-aged subjects with the emphasis placed on their subjective reaction to that exercise before and after training. Rather than employ a battery of psychological tests to assess such reactions the simple, but effective, expediency of using a single Rate of Perceived Exertion (RPE) was adopted [continued]…