Lack of physical activity is one of the main risk factors for premature death, along with smoking and poor diet [1
]. It is recommended that young adults engage in at least an average of 60 min per day of moderate physical activity or a minimum of 150 min of vigorous physical activity per week [2
]. Despite this, globally, physical inactivity and a sedentary lifestyle occur in almost 30% of adults and in more than 80% of school-age adolescents [2
]. In general, the population is more physically inactive in developed countries [1
]. Likewise, there are also differences between the sexes, with girls and young women being the most sedentary [5
]. In addition, it is known that during the passage from adolescence to adulthood there is a greater decrease in physical activity [5
], this decrease coinciding with the beginning of university study [10
]. This situation has now been worsened by the COVID-19 pandemic [11
Physical activity implies multiple benefits, such as the prevention of cardiovascular diseases [12
], better control of body weight [10
], less presence of chronic pain [14
], better bone density and better physical fitness [15
], greater muscle strength, and lower risk of mortality [13
]. In addition, at a psychological level, physical activity improves mental health and quality of life [8
], reduces stress and anxiety [8
], lowers the risk of depression [22
], and improves the quality of sleep [23
]. Likewise, physical activity is positively related to better academic performance among university students [24
]. In short, physical activity and exercise are associated with psychological and social well-being [25
Psychological well-being is made up of self-acceptance, positive relationships, autonomy, mastery of the environment, purpose in life, and personal growth. [26
]. It is known that these benefits are affected by the prior beliefs and expectations that the person had towards that physical activity [27
]. Similarly, there are a number of circumstances that make exercise difficult or prevent it, such as lack of time [28
], lack of social support [29
], economic difficulties [29
], physical discomfort [30
], and lack of motivation [29
]. Specifically, research has found that one of the factors that most influences physical activity performance is self-determined motivation [33
According to Self-Determination Theory (SDT) [38
], motivation occurs as a continuous process involving different degrees of autonomy [40
]. SDT establishes two types of motivation: intrinsic, which refers to more self-determined behaviours where the person acts of their own free will or for their own enjoyment, and extrinsic, which refers to more controlled behaviours where the individual’s motivation comes from the outside and implies a certain pressure to behave in a certain way [35
]. Thus, if a person gets involved in an activity out of interest in the activity itself, it will be easier for them to adhere to this activity; whereas, if the person performs an activity for instrumental reasons or to obtain certain results, such as rewards or social recognition, it will be more difficult for them to reach an adequate level of involvement and for the behaviour to be consolidated [33
SDT also tells us that the satisfaction of basic psychological needs (competence, autonomy, and relationships with others) can promote self-determined motivation and, in turn, have repercussions on the cognitive, affective, and behavioural consequences of psychosocial well-being [37
]. In addition, those social contexts that satisfy people’s competence, autonomy, and relationships will also foster intrinsic motivation and, therefore, more autonomous and lasting behaviours [35
]. Given that SDT seems to be a key in predicting self-determined behaviors related to physical activity among university students, and that there are few studies on this topic and its relationship with psychological and social well-being in this population [36
], this study was carried out. The studies carried out to date have investigated the quality of life [36
]; they have focused only on men [41
]; have studied life satisfaction [42
]; or have wanted to develop a predictive model that relates physical activity and psychological aspects [43
]. The aim of this study was thus to explore the association between physical exercise, motivation, and psychological well-being in young adults. More specifically, we tried to define those factors that motivate taking physical exercise and their influence on psychological well-being.
The aim of this study was to analyze the relationship between physical exercise, motivation, and psychological well-being in young adults. In general, the data obtained reflect a profile of a young adult with a university education, with a higher percentage of women. Both men and women mostly had a BMI within a normal range and were physically active, with a higher level of physical activity among men. The mean scores showed moderate levels of both psychological well-being and motivation, obtaining higher scores at the level of intrinsic motivation. In these last two variables, it should be noted that the men showed higher scores related to high levels of activity.
This research has shown that performing physical activity has a direct relationship with the psychological well-being of the people who practice it. However, one of the main contributions of this work is reflected in the role of motivation in carrying out physical activity. Thus, although the importance of self-determined behaviors in exercise has been observed, this work also highlights the possible role that extrinsic motivation may have in starting physical activity and how it may have a certain importance when physical activity levels are high.
Therefore, responding to the aim of the study, it was possible to observe a correlation between physical activity and the psychological well-being of the participants. Furthermore, when analyzing the data according to the level of physical activity, higher mean scores were observed for a high level of activity. These data agree with the results of studies such as that of Marfil–Carmona et al. [47
], in which participants showed greater psychological well-being when their physical activity was higher. These authors reported that this is mainly due to the fact that physical exercise promotes self-care and keeps people away from risk factors for their health. Moreover, in works such as that of Grasdalsmoen et al. [48
] it has been observed that the frequency of physical exercise is negatively associated with depressive symptoms since physical activity favours the release of endorphins and maintains mitochondrial function. Furthermore, as An et al. [49
] and Morgan et al. [50
] state, physical activity promotes greater life satisfaction as it improves the general state of health and increases the individual’s self-efficacy, which directly influences their psychological well-being. When comparing the level of exercise between men and women, it was observed that, although both genders had a high and medium level of activity, men showed significantly higher levels of physical activity. Men tend to understand physical activity as a challenge, and their purpose is usually aimed at personal growth, which makes them have a better self-image and self-knowledge that is reflected in their greater psychological well-being [41
]. However, it has been observed that the influence of the media results in them being unable to reach certain ideals of beauty and to feel greater dissatisfaction [47
], which may fit in with the moderate scores found at the level of psychological well-being.
On the other hand, the data obtained indicated the existence of a correlation between motivation and physical activity so that at high levels of physical exercise, higher scores were obtained on the level of motivation. More specifically, significant differences were observed at the level of intrinsic motivation between the groups with different levels of physical activity, while at the level of extrinsic motivation these differences were only observed between the group with high levels of activity and the rest. These data agree with various studies [41
] that show that physical activity is related to the most self-determined types of motivation, in addition to showing a slight influence of extrinsic motivation when the activity is vigorous. González–Hernández et al. [54
] report that people perform physical exercise because they are motivated by internal elements, such as feeling pleasure, escaping or feeling competent, and by external elements, such as being strong and, above all, interacting with other people and having fun. Following this same line, the work of Tao et al. [36
], points out the importance of extrinsic motivation to start exercising, with support from family and friends being a key element—as seen in the data of this study. Nevertheless, they understand that intrinsic motivation has a fundamental role in maintaining physical activity, and perhaps for this reason it is more strongly related to higher levels of physical activity [36
]. Therefore, the results found in this research reflect the basis of the SDT, since they show that the development of self-determined behaviors (intrinsic motivation) favors adherence to physical activity and allows greater satisfaction with it. However, the data presented show that external pressure to behave in a certain way or achieve certain goals (extrinsic motivation) also seems to play a key role in starting physical activity [33
In relation to these data, the linear regression model showed that intrinsic motivation was the most determining factor in predicting the level of physical activity, acquiring greater weight among men. This model agrees with other works [41
] that discovered that men exercise to improve their self-image, with the aim of fulfilling a life purpose and overcoming challenges, which are characteristic elements of intrinsic motivation. However, women are motivated by factors such as improving their physical condition, losing weight, or reducing body fat, basing their motivation on elements that are external to the person [47
]. In addition, with the data obtained from the multiple regression analysis, it was found that the intrinsic motivation model was influenced by vigorous activity in both men and women, indicating the feedback between the increase in intrinsic motivation and the level of activity. This finding coincides with the results of Sevil et al. [56
], who point out that those with a higher level of activity show greater intrinsic motivation than people with a low level of activity, who have greater extrinsic motivation. This leads us to think that once people are capable of carrying out high-intensity physical activity, those skills that determine extrinsic motivation remain in the background, giving way to those related to intrinsic motivation [36
]. Therefore, these data once again reinforce the idea exposed in the SDT, which suggests that acting of one’s own free will and for fun will favor adherence to physical activity, leaving aside those behaviors that seek external reinforcement and that involve less of the person in the physical activity [34
]. However, as previously mentioned, certain works [41
] report that extrinsic motivation may be present to a small extent in high-intensity activities, with factors such as being in shape or appearance having a certain importance.
Finally, as was the case with physical activity, intrinsic motivation was correlated with psychological well-being, given that that the greater the motivation, the greater their well-being. These data agree with the results of Martín–Albo et al. [57
] and Marfil–Carmona et al. [47
], who show that people who have a higher intrinsic motivation tend to have a better self-perception, which produces an increase in their psychological well-being by feeling more competent and more satisfied. In addition, these data are reinforced by the relationship observed between the enjoyment subscale, a determinant of intrinsic motivation, and psychological well-being in all its areas. Thus, enjoyment seems to be the intrinsic motivational factor that most influences the well-being of people with a moderate–high level of physical activity. These results coincide with those of a study carried out by de Vries, van Hooff, Geurts, & Kompier [58
], which, in addition to demonstrating that enjoyment is closely linked to adherence to physical exercise, showed a clear relationship between those people who had a greater enjoyment when performing physical activity and their psychological well-being.
On the contrary, extrinsic motivation did not show a correlation with psychological well-being, also reflecting a negative relationship with the autonomy subscale within this variable, which may suggest that those people who depend more on external factors when exercising have less capacity to lead their lives autonomously. These data could be explained through the SDT. As reflected in this theory, the satisfaction of needs such as competence and autonomy imply greater intrinsic motivation and self-determination, and this leads to greater psychological well-being [33
]. Moreover, these results concur with the study by Weman–Josefsson et al. [53
], where it is shown that the extrinsic part of the motivation for exercise is reduced by providing support for the growth of autonomy. Furthermore, this autonomy was negatively related to elements of extrinsic motivation, such as concern for appearance or social relationships. This might indicate that those people who are more aware of their physique and appearance are less capable of leading their lives autonomously, which coincides with the results obtained by Miquelon et al. [59
], who state that people who show greater dependence on their physical activity are less autonomous in their daily lives. In the same way, when observing the data from the linear regression model, this negative influence of the social aspect of motivation on psychological well-being in both men and women is reinforced so that it seems that when a motivation dependent on the social environment predominates, psychological well-being is impaired.
The study presents a series of limitations, which might condition the results found and therefore the conclusions drawn from it. First, the type of sampling makes it difficult to generalize the results. Second, self-administered surveys present a social desirability bias that makes subjects say what they are expected to answer or what is accepted by society in general and therefore hide the truth. Third, no objective measures of physical activity were collected; this information was solely obtained through a survey. Fourth, the availability of online and free access questionnaires makes it impossible for researchers to recognize whether the same subject answers the survey on more than one occasion, which could affect the data collected and the results found. Lastly, no causal relationships can be described due to the study design.
Therefore, it is necessary to carry out controlled and randomized experimental studies that investigate the true effects of physical exercise on the psychological well-being of those who practice it in the short, medium, and long term. In addition, the results found in this study provide relevant information to help health professionals work on motivation in order to achieve adherence to physical activity and improve the psychological well-being of their patients. Therefore, it would be interesting to develop recommendations and action plans that take into account that, in the initial stages, physical activity is influenced by social reinforcement, and, in later stages, self-determined behaviors will be the key factors for the consolidation of physical work. In addition, the data show that it is necessary to adopt different approaches according to gender, since the reasons for performing physical activity are different according to it. Finally, health professionals work with people who, due to different pathologies or health situations, do not have a good psychological well-being so that, according to what is exposed in this research, introducing physical activity could be an important factor in helping them to feel better.