Exercise performance can be measured primarily in two ways. One way concerns the actual improvement of performance, for instance, swimming faster, running longer distances, lifting more weight, or performing more efficiently. The second way is being motivated to perform in the first place and adhering/ sticking with an exercise program for the long term. Both approaches are considered in this chapter.Exercise adherence is a precursor to improvement of performance. If a person is not motivated to exercise, then exercise performance doesn't occur. If a person is motivated, but motivation is episodic/ spotty/inconsistent, then performance is hindered and the potential benefits of regular exercise will be difficult to obtain. Therefore, adherence to exercise programs is critical for improved fitness and experiencing its benefits.We must first define the term exercise before suggesting strategies for improving exercise performance. We favor the definition of exercise by Acevedo ( 2012), who defined exercise as "a form of structured physical activity with the specific objective of improving or maintaining physical fitness or health" (p. 4). This term is sometimes used interchangeably with physical activity (PA), as Acevedo noted "in parallel with the literature, 'physical activity' and 'exercise' are often used interchangeably" (pp. 4-5). PA is most commonly defined as any physical movement that works muscles and requires more energy than being at rest (National Heart, Lung, and Blood Institute, 2016). There are many examples of PA, such as walking, dancing, playing, yoga, or even gardening. PA is generally considered less structured than exercise (National Heart, Lung, and Blood Institute, 2016). Exercise is one form of PA; PA can be seen as an umbrella concept that encompasses exercise but also other forms of PA that we would not characterize as exercise per se. Although we use the term exercise in this chapter, one should consider PA in general as well (Ciaccio & Sachs, 2017).Yet another key component to exercise performance in both its basic and adherence sense is motivation. The term motivation comes from the Latin word movere, meaning "to move," or what moves the person to initiate or maintain behavior (Dörnyei & Ushioda, 2013). Movement has two reference points here: first, the actual physical movement that is integral to exercise and PA, and second, the idea of moving from sedentary behavior toward movement/ PA/exercise. That is, as opposed to being sedentary (lack of movement), one chooses to move, in this case, engaging in exercise.For the purposes of this chapter we examine exercise performance initially in its basic sense, then elaborate on how to improve it. Our discussion taps into the use of psychological skills for improving exercise performance, including goal setting, arousal control, imagery, attention and concentration, self-talk, and finally a brief discussion on mental toughness. Then we delve into performance as it relates to exercise