1. Introduction
The mental health of university students has been a prominent area of study. According to a worldwide study of college students [
1], one-fifth of college students had a clinically significant mental health disorder. Similarly, a study of over 2000 university students in Australia observed that one in four students reported a mental health disorder [
2]. The COVID-19 pandemic has exacerbated the existing negative impacts of mental health problems due to increased anxiety about health, decreased social interaction, and increased worry about academic performance [
3]. This has brought an urgent need for positive interventions to improve mental health in university students.
Resilience, defined as the ability to adapt positively after experiencing adversity, provides protection for negative mental health during challenging times [
4]. Resilient people tend to be optimistic, emotionally aware, social, and able to confront issues while maintaining perspective and daily function [
4]. In other words, resilience represents a strength to overcome obstacles with competence and hope. In a study of 7800 college students, it was found that resilience played a mediating role between the association of COVID-19 stressful experiences and acute stress disorder [
5].
Physical activity is crucial in developing and strengthening resilience [
6]. A study found a positive relationship between physical activity and resilience in college students [
7]. Furthermore, a study found that PA level was significantly correlated with resilience in Chinese 7th and 8th graders [
8]. Helping students engage in PA and giving resources to promote the continuation of PA engagement can thus be inferred to positively affect resilience. Despite the beneficial effect of PA on resilience, university students tend not to be engaging in the recommended amounts of exercise [
9]. In a study of 296 university students, it was found that only 5.4% of students met the WHO’s PA recommendation of 150 min/week of moderate to vigorous physical activity (MVPA) or 75 min/week of vigorous PA [
10]. However, virtual PA interventions may help to increase this low engagement, especially during the pandemic. In a web-based randomized control trial of mothers, it was found that after engaging in an 8 week video-based exercise intervention (5–30 min of video-based exercise 5 days per week), the intervention group increased their MVPA by 42.2 min compared to the waitlist control group [
11]. In a randomized control trial of 64 young adults during the COVID-19 pandemic, an intervention group received weekly YouTube video-based aerobic and resistance exercises while a control group received general health education videos for 12 weeks [
12]. The intervention group significantly increased MVPA, but did not significantly increase light PA [
12].
Different intensities of PA can also impact resilience. A study of 244 undergraduate students found that the higher scores of resilience were significantly associated with increased vigorous PA [
13]. Additionally, in a randomized controlled trial of 67 adults, the results indicated that both high-intensity interval training and moderate-intensity training increased resilience [
14]. Similarly, study of Spanish adults early in the pandemic found that individuals who engaged in VPA during the first week of isolation reported higher resilience [
15].
Mindfulness is the heightened awareness that develops through intentional non-judgmental attention to the present [
16]. Mindful exercise is mindfulness with the addition of physical exertion and extra attention to proprioception [
17]. Mindfulness and mindful exercise can also be a tool to build and maintain resilience. In a cross-sectional study of 106 nursing undergraduates, a strong positive relationship between resilience and mindfulness was found [
18]. Moreover, mindful exercise such as yoga can be beneficial in increasing resilience. In a randomized controlled trial of 121 adolescents, it was found that a yoga intervention including simple yoga poses, breathing exercises, and visualization insignificantly increased resilience from baseline, while the control group significantly decreased their resilience [
19]. Furthermore, an intervention study of 123 rural-urban migrant college students found that students who engaged in a 40 session yoga intervention reported a significantly higher total resilience score as compared to the control group [
20].
Due to COVID-19 precautions, virtual interventions are at the forefront of research. A systematic review of web-based PA interventions found that most significantly increase PA in its participants. [
21]. Additionally, virtual platforms provide increased flexibility and lower costs [
21]. Moreover, in a systematic review of university students early in the pandemic, significant reductions in all intensities of physical activity were found [
22]. As universities enact strict social distancing policies to mitigate spread of COVID-19, college students need COVID-19-safe physical activity and mindful opportunities. Virtual aerobic exercise may provide this opportunity for PA. In addition, mindfulness-based yoga may combine the benefits of physical activity and mindfulness, benefitting students physically and mentally. However, the effects of a web-based exercise and mindful intervention on resilience and all PA intensities are not well known. Therefore, the purpose of this study was to examine the immediate and short-term effects of virtual aerobic and mindful exercise interventions on physical activity intensity engagement and resilience among college students. It is hypothesized that the interventions may increase various intensity levels of PA and resilience from pre-test to post-test, and six-week follow up. Regarding intensity, it is hypothesized that the aerobic and resistance exercise group, WeActive, may increase MVPA and the mindful yoga exercise group, WeMindful, may increase walking PA from pre-test to post-test, and six week follow up. This study is significant in that the results may help inform university administrators as they plan exercise and mindfulness sessions that strive to increase the physical activity and resilience of their students.
4. Discussion
This study aimed to examine the immediate and short-term effects of virtual aerobic-strength exercise and mindful exercise interventions on physical activity intensity engagement and resilience among college students. As partly hypothesized, the WeActive group showed an increase in TPA at each time point although not reaching a significant level; however, the WeMindful group saw an initial increase and then a decrease in TPA. In relation to intensity, the WeActive group increased VPA significantly from pre-test to post-test and MPA from pre-test to follow up. The WeMindful group did not show any significant changes in VPA and MPA at any time point. However, the WeMindful group saw an initial non-significant increase in walking PA from pre-test to post-test followed by a significant decrease from post-test to follow up. The WeActive group did not show any significant changes in walking PA at any time point.
Congruent with the hypothesis, both groups significantly increased resilience from pre-test to follow up. This increased resilience demonstrated in both the WeActive and WeMindful groups may be due to a biological mechanism associated with exercise. Individuals who are more physically active tend to have lower cortisol levels, which are associated with lower levels of depression [
29]. Additionally, it was found that after individuals were instructed to refrain from exercise, lower parasympathetic nervous system activity was observed along with reported negative mood [
29]. Those who exercise may have a lower pre-test stress and can therefore handle increases in stress better than inactive individuals. Additionally, increased aerobic fitness is associated with increased prefrontal gray matter [
29]. This increase could allow subjects to plan better and think more clearly when confronted with an obstacle. Lending support for the present results, previous studies of over 700 University students in Spain have found that higher levels of moderate PA are associated with greater resilience [
30,
31]. Further, a cross-sectional study in Spain during a national COVID-19 lockdown showed that older adults who engaged in MVPA scored better on the resilience scale [
15].
Additionally, a study found that VPA is associated with increased resilience; however, there was no such relationship for MPA [
13]. This indicates that VPA may account for a larger contribution to the increased resilience found in the WeActive group. Further studies on the specific adaptations from vigorous versus moderate physical activity should be examined to better understand how different PA intensities influence resilience.
The WeActive group saw a significant increase in MPA from pre-test to follow up. The WeActive intervention sessions included MPA exercises. A previous randomized controlled trial of 110 sedentary adults found that a web-based PA intervention including self-monitoring, pedometers and social elements delivered through social media significantly increased moderate–vigorous PA as a primary outcome; however, there were no significant changes in VPA [
32]. This increase was not sustained at the 20 week follow up [
32]. The participants in WeActive may have enjoyed an instructor-led class instead of self-monitoring. Moreover, 145 undergraduates retrospectively reported significantly less VPA in college than in high school [
33]. Combined with the findings of the current study, university students may engage in more and prefer MPA over VPA. The discrepancy between WeActive’s significant increase in MPA while WeMindful did not see such an increase may be due to the higher intensity of the WeActive PA intervention. While the participants had access to both intervention materials after the intervention period was over, the WeActive participants completed the strength and aerobic, moderate-intensity, circuits while the WeMindful participants completed lower-intensity PA. Therefore, the WeActive participants who are familiar with the MPA materials are more likely to continue to engage in MPA after the intervention than the WeMindful participants.
The WeMindful group engaged in an 8 week virtual yoga exercise and mindfulness meditation. A significant increase in resilience was found between pre-test and follow up. Consistent with the present results, a short-term increase in resilience was found among forty-four participants who engaged in six weekly mind-body intervention sessions [
34]. Similarly, a study found that after engaging in a 9 week mind-body intervention, 279 students showed a significant increase in resilience and mindfulness, compared to 247 students who did not engage in the intervention [
35]. Mindfulness was sustained at one-year follow up, suggesting positive long-term impacts of the intervention [
35]. Contrary to the current findings, an intervention study with 232 medical students during one semester in New Zealand did not find a statistically significant difference between a weekly peer-led mindfulness group and the control group [
36]. One possible reason for the contradiction could be the social component. The peer leaders in the study by Moir et al. were chosen through applications and nominations. A positive, respectful, and supportive group atmosphere is crucial to mind-body interventions [
35]. It is possible that the group dynamics were less supportive as it is described that there may have been compensatory rivalry between the intervention and non-intervention groups [
36]. More research should be conducted into group social dynamics and their impact on mindfulness training.
It is worth noting that one advantage of the WeActive and WeMindful intervention programs was their virtual delivery. Participants in Lowenthal et al. expressed that virtual delivery would have increased conveniency for busy individuals, possibly by cutting down on travel time [
34]. The participants in the WeActive and WeMindful groups had the added benefit of the second weekly session to be asynchronous. This means that students could complete the second weekly exercise session at the most convenient time for their schedules. Further, in a previous virtual aerobic and yoga intervention study of 71 university students, participants reported that the intervention was acceptable, appropriate, and feasible for them [
16]. Virtual delivery likely contributed to this positive feasibility as it is a flexible option for busy participants who may have varying schedules week to week.
A strength of the current study is that it included students from various study years. There is a relatively even distribution of first, second, third, fourth, masters and doctoral students. Each year brings about new challenges and learning about resilience throughout the university journey is an advantage. It is advised that the findings from this study are used to inform university authorities to increase access to mindfulness resources and aerobic and resistance exercises to increase the resilience of their student population.
However, the virtual setting also has a limitation. The participants muted their sound and camera throughout the WeActive and WeMindful sessions. The instructors were unable to answer questions or check physical form. Although the virtual delivery allows for schedule flexibility, another limitation is the difficulty in assessing engagement accuracy. Participants were allowed to complete the second session asynchronously each week and self-report completion. This means the engagement rate could be subject to self-report bias. Along with engagement rate, PA and resilience were both measured through a self-report questionnaire which could be affected by self-report bias. Another limitation of this study was that it was conducted during the COVID-19 pandemic. Students were under a lot of unforeseen stress throughout the intervention and follow up. Some students may have been facing large novel obstacles that could have affected their perceived resilience. While the intervention being held during a pandemic allows for a snapshot in time, it can be less generalizable to a post-pandemic situation. The addition of a control group to this study would also add a better understanding of the effects of aerobic-resistance training and mindful yoga exercises had on resilience. Additionally, in the current study, the Cronbach alpha for the IPAQ ranged from 0.75 to 0.84. In previous research, the IPAQ short form had a reliability coefficient ranging from 0.71 to 0.89 for university students [
37]. The current study falls within this range. This presents as a possible limitation as previous research has indicated that a reliability coefficient of 0.80 or greater is required to examine mean differences among groups [
38]. Moreover, the lack of diversity in participants is a limitation of this study. Cisgender females made up 84% of the participants and 65% of the participants were white. According to a cross-sectional study of 77 undergraduate students, 79.2% who were white, it was found that a significantly higher proportion of male students were adequately physically active based upon accelerometer data [
39]. The high percentage of cisgender females may have caused bias in the current study results. In a cross-sectional study of American university students, it was found that reported MPA was not significantly different between men and women; however, men engaged in significantly more VPA. [
40]. Therefore, a large representation of cisgender females could cause bias; however, this study adds to the literature on exercise intervention effects on female students. Additionally, a cross-sectional study of 606 university students revealed that significantly more non-Hispanic white students met the MVPA recommendations by the 2018 Physical Activity Guidelines by the Department of Health and Human Services [
40]. Thus, more research should be conducted on the ways in which student’s race influences exercise intervention effects.