Exercise is an important health behavior. Expressed reasons for participation are often delayed outcomes i.e. health threats and benefits, but alsocan be immediate likeenjoyment. However, it was not knownhow people evaluate exercise as a reward. The value of rewards diminishes with delays,and the delay discounting effect can undermine decision-making.Delay discounting(assessed by discounting rate -k value)is defined as the decline in the subjectivevalue of a reward with delay to its receipt.Exercise subjectivereward valuation is a principalstep in decision making. However, apartfrom the decision to participate in exercise, further decisions regarding specific parameters need to be made. The selection of exercise intensity might be influenced byvisceral factors and motives related togoals, but theprincipal evaluation of exerciseper seis yet to be explored. The general aim of this thesis was to investigate the delay discounting of exercise in comparison with food and money in healthy adults. It also aimed to investigate whether body characteristics, physical activity, and selected physiological and psychometric measures were associated with k values.In chapter 2, based on the aboveaims, self-paced exercise sessions on treadmill were conducted and the k valuesof exercisewerecompared with those of food and money.The outcomesshow that young, moderately active participants (n=70) preferred walking/running intensity with low to moderate cardiovascular strain and light perceived exertion. kvaluesindicated that exercise was discounted like consumable rewards as food and more rapidly than monetary rewards.Significant associations were detected of exercise k valuewith preferred speed and with extrinsic exercise motivation. High intensity exercise training(n=16) reduced exercise k valuesspecificallyand exercise k valuewas quicker in individuals who preferred lower speeds being less physically active. In chapter 3, theobjectiveswere to investigatewhether thevisceral reward and self-selectionof exerciseare modifiablein connection to the exercise physiological strainthrough high intensity interval training. Toaccomplish this target, exercise training and evaluative conditioning(EC) were combined. Using a randomized control design (N=58). Pre, post three weeks interval training w/o conditioning, and after 4 weeks follow-up, participants were tested on self-paced speed selection on treadmill, delaydiscounting of exercise and food rewards. Outcomes revealed that delay discounting of self-paced exercise was specifically influenced by training but not by EC. However, selection of intensity was significantly increased by ECand physiological adaptation to training, revealing the importance of visceral factors. In agreementwith effort discounting models, the choice for a self-selected intensity depended on the acutely perceived pleasantness of exercise, discounted against perceived effort. This suggests a separation of decision-makingprocesses for the evaluation of exercise, based on cognitive processes, and intensity selection of self-paced exercise, based on rewarding visceral experience of physical strain. In chapter 4, an online survey was conducted to investigate the reward value of un-specific exercise experienceto enable a wider spectrum of ecological and psychological characteristicswith integrating aspects of passive sports consumption related screen timeand reward preference. Across sectional design through a Qualtricsonline survey have been used to recruit200participants on Amazon’s Mechanical Turk. Results showthatun-specific exercise experience was found to be discounted as established rewards.Significant negative associations were detected of exercise discounting rateswith extrinsic exercise motivation, physical activity levels, and positive associationwith sports-screen time. This suggests that reward valuation and discounting of exerciseis not specific to a certain exercise typeor intensity, and that passive consumptionis linked to higher exercise discounting through reinforcing immediate enjoyment.Finally, chapter 5 provides a summary of the thesis findings and clarifies the novelty of the current thesis. Italso outlines the future implications of the findingsfromresearch perspectivesand addresses the strengths and limitations of the thesis as well as the general conclusion.