Purpose – The main research questions addressed by this study focus on Subjective Well-Being (SWB) and to what extent the individual’s SWB relates to the individual’s need for personal growth. Specific interest is devoted to the effects of intentions (to have personal goals) and behavior (to achieve personal goals). Design/methodology/approach – Can SWB and happiness research help to explain the tremendous growth in demanding amateur sport event participation? Most research on SWB and events has, so far been undertaken on cultural events leaving a gap related to sport events, especially obstacle running events. Bestial is an obstacle race event held in Arucas on Canary Islands, Spain. Apart from competitiveness, the race also contains elements of altruism as many competitors do help each other at various obstacles along the route, in groups (mainly) teams. A sample of 700 participants answered questions about behavior, attitudes and SWB. Findings – The results show significant relations between SWB and both intentions and behavior but also that intentions and behavior are not correlated. Research limitations/implications – The “Bestial” is different from an average running event in some respects. It is a rather local event for Gran Canaria without international participation. For some participants it is more challenging and enduring but for others it is a team sport where one helps other team members to complete the race. In this study, these two types of participation have not been separated. The test of whether the SWB of participants is higher than the SWB of the average citizen is not satisfactory. Data for the average of SWB in Spain had to depend on a study from another year and where standard deviation was not available. Practical implications – The results of this work are useful for event managers to improve their design and develop the most appropriate marketing messages. Social implications – The study aims for an explanation to why demanding physical activities, such as obstacle races, are so popular. In this study of obstacle race participation, hedonia is regarded as less relevant and focus is on eudaimonia and an assumption that participants in an obstacle race have a high SWB since they can feel that they make progress towards goals. One intended contribution of this study is to distinguish between “to have a goal” and “to progress towards a goal”. Thus, the model proposed is based on hypotheses that SWB is influenced by both. Two types of goals are studied: first a mainly individualistic goal of becoming physically fit and second a more altruistic goal of “becoming a better person”. Originality/value – In the conclusions, the importance for a happy life of simply having goals for personal growth and the value of anticipation for happiness is discussed.