Psychological determinants of physical activity

In the first part of this section, the detailed results of the short-term (see Table 22) and the middle-term (see Table 22) within-group analysis of the psychological determinants of physical activity are presented. In the short-term, significant changes were observed in students’ attitudes towards the health effects of physical activity and towards PE, their knowledge of the health effects of physical activity, their enjoyment in PE, and their self-efficacy. In the middle-term significant changes were measured in students’ attitudes towards the health effects of physical activity, their intrinsic motivation and enjoyment in PE as well as their self-efficacy.

Table 22 Short-Term Within-Group Differences in Psychological Determinants of Physical Activity

Variable Group T1

Chapter 4: Intervention Study

a Intervention effect in favour of the IG.

b Intervention effect in favour of the CG.

Table 23 Middle-Term Within-Group Differences in Psychological Determinants of Physical Activity

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138

Variable Group T1

M ± SD

T3

M ± SD T df p 95% CI d

CG 5.15 ± 1.22 5.02 ± 1.14 .97 66 .34 -.14; .40 0.11 Boys IG 5.44 ± 1.18 5.23 ± 1.41 1.41 56 .16 -.09; .49 0.16 CG 5.25 ± .63 4.72 ± 1.16 2.68 29 .01^b .13; .94 0.57

Enjoyment in PE

Total IG 5.37 ± 1.45 4.90 ± 1.46 3.25 97 <.001^b .18; .74 0.32 CG 5.38 ± 1.30 4.98 ± 1.46 2.64 95 .01^b .10; .70 0.29 Girls IG 5.55 ± 1.47 5.10 ± 1.04 1.93 36 .06 -.02; .91 0.35 CG 5.54 ± 1.17 5.36 ± 1.43 1.09 64 .28 -.15; .50 0.14 Boys IG 5.26 ± 1.44 4.78 ± 1.65 2.60 60 .01^b .11; .84 0.30 CG 5.05 ± 1.52 4.19 ± 1.21 2.82 30 .01^b .24; 1.48 0.63

Self-efficacy

Total IG 4.43 ± 1.16 4.29 ± 1.46 1.00 107 .32 -.14; .43 0.11 CG 4.32 ± 1.28 4.72 ± 1.23 -1.93 51 .06 -.82; .02 0.32 Girls IG 4.53 ± 1.08 4.42 ± 1.33 .76 74 .45 -.17; .39 0.09 CG 4.25 ± 1.29 4.82 ± 1.07 -2.54 23 .02^a -1.04; -.11 0.49 Boys IG 4.21 ± 1.32 3.99 ± 1.70 .66 32 .52 -.48; .94 0.15 CG 4.38 ± 1.29 4.64 ± 1.37 -.76 27 .45 -.95; .44 0.19

a Intervention effect in favour of the IG.

b Intervention effect in favour of the CG.

The analysis of the short- and middle-term within-group development of students’ attitudes towards the health effects of physical activity (see Figure 12a) showed that IG girls had a significant short-term positive change in their attitudes (d = .34) whereas the CG girls remained on the same level. In the middle-term there were no significant changes in any of the groups. In boys, no significant changes on the attitudes towards the health effects of physical activity were observed. Nevertheless, in the short-term the IG decreased their positive attitudes slightly and remained stable in the middle term. CG boys showed a slight non-significant increase in the short- and middle-term. When examining the total group without separating the students by gender, short- (d = .21) and middle-term (d = .20) positive significant changes were observed only in the IG. The analysis of students’ attitudes towards PE (see Figure 12b) did not reveal any short- or middle-term significant changes in girls of the IG and the CG. A significant reduction in the IG girls’ attitudes towards PE was only observed in the follow-up timeframe (T2-T3). In boys, this analysis revealed a different picture: a short-term significant reduction of attitudes towards PE was measured in the IG boys (d = .36). No significant changes were measured in the CG boy and in the gender independent analysis.

The short- and middle-term within-group changes of students’ knowledge of the positive health effects of physical activity are shown in figure 13a. Even though the IG girls increased their short-term knowledge, the changes were not significant. CG girls non-significantly decreased their knowledge in this timeframe slightly. Also in the middle-term, no significant changes could be observed in girls’ knowledge. Boys in both groups, showed an increase in knowledge in the short- and middle-term but also here the changes were not significant. Only in the gender independent analysis a short-term positive significant change occurred in the IG (d = .23).

When looking at the development of students’ self-efficacy levels towards regular physical activity, an opposite trend between students of the IG compared to the CG was revealed (see

Chapter 4: Intervention Study

139 Figure 13a). CG students showed an increase in efficacy levels whereas IG students’ self-efficacy decreased over time. These changes in the self-self-efficacy levels were only significant in the CG girls in the short- (d = .50) and middle-term (d = .49).

Figure 12 Short- and Middle-Term Developments of Attitudes Towards the Health Effects of PA (a) and on Attitudes Towards PE (b) in the IG and the CG Over the Five Month Investigation Period.

Figure 13 Short- and Middle-Term Developments of Knowledge and Self-Efficacy in the IG and the CG Over the Five Month Investigation Period.

4,0

Attitudes towards health effects of PA (a)

4,0

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140 The changes in students’ external, identified, and intrinsic motivation towards physical activity based on the theory by Deci and Ryan (2004) as well as students’ enjoyment in PE are described in the following (see Figure 14). The external motivation to participate in exercise did not significantly change in any of the groups either in the short- or in the middle-term.

Interestingly, a slight decrease was observed in IG girls and CG boys whereas a slight increase was measured in CG girls and IG boys. No significant changes were measured in the gender independent analysis in the short- and middle-term, but a significant reduction in the IG was measured in the follow-up timeframe (T2-T3). Also concerning students’ identified motivation to participate in physical activity, there were no significant differences during the short- and middle-term. Only during the follow-up (T2-T3), a significant reduction in IG girls and boys as well as for the entire IG was observed. The changes in students’ intrinsic motivation to participate in physical activity showed no significant short- and middle-term changes in any of the groups except from a significant reduction in the CG boys in the middle-term (d = .57). During the follow-up (T2-T3), a significant reduction was observed in boys of the IG and in the entire IG. The gender independent analysis showed a significant reduction in the CG in the middle-term (d = .23).

In girls, the developments concerning enjoyment of PE were similar to the changes in intrinsic motivation towards physical activity. In the short- and milled-term, no significant changes occurred in girls. Only during the follow-up timeframe (T2-T3), both IG and CG girls showed a significant decreased in enjoyment of PE. In both IG and CG boys, a significant decrease in PE enjoyment was measured in the short-term (d = .27, d = .53 respectively) and in the middle-term (IG: d = .30, CG: d = .63). Finally, in the gender independent analysis, a significant reduction in PE enjoyment was measured in both groups in the middle-term (IG:

d = .32, CG: d = .29).

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141 Figure 14 Short- and Middle-Term Developments of Motivation Towards Physical Activity and PE in the IG and the CG Over the Five Month Investigation

Period (IG Girls: T1=41, T2=36, T3=37; CG Girls: T1=73, T2=64, T3=67) (IG Boys: T1=73, T2=59, T3=61; CG Boys: T1=36, T2=31, T3=30).

3,5

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142 Between-group differences

In a first step, the short- and middle-term intervention effects on the examined psychological determinants of physical activity based on the entire IG and CG were analysed (see Table 24).

When considering the estimated means of the two groups it is shown that the IG had higher scores in the attitudes towards physical activity, in the external, identified, and intrinsic motivation as well as the enjoyment in PE. The results from the ANCOVA revealed only two significant differences between the IG and the CG: A short-term (T2) positive intervention effect on students’ external motivation towards physical activity was revealed and in the middle-term (T3), a negative intervention effect was measured on students’ self-efficacy levels.

In a second step, the same analysis was carried out separately for the two genders (see Table 25). Also here the estimated means reveal a positive picture of the effects of HealthyPEP on the students. IG girls have higher values on attitudes towards physical activity, in the identified and intrinsic motivation, the enjoyment in PE, and in knowledge. IG boys showed higher values compared to the CG boys in attitudes towards physical activity, in the external, identified, and intrinsic motivation, the enjoyment in PE, and in knowledge. Nevertheless, negative short- and middle-term significant intervention effects were found in IG girls self-efficacy levels. Additionally, short-term negative intervention effects were revealed in IG boys attitudes towards PE.

Table 24 Short- and Middle-Term Intervention Effects on Psychological Determinants of Physical Activity in the Total Group (Estimated Means (± SE), Controlled for T1-Values and Baseline BMI Values)

IG CG

Variable Time

N M ± SE N M ± SE F p η² d

Attitudes PA T2 116 5.92 ± .06 42 5.71 ± .10 2.95 .09 .02 0.25 T3 115 5.92 ± .06 54 5.79 ± .09 1.35 .25 .01 0.16 Attitudes PE T2 113 5.50 ± .08 42 5.79 ± .13 3.51 .06 .02 0.22 T3 113 5.48 ± .08 54 5.69 ± .12 2.14 .15 .01 0.16 Self-efficacy T2 111 4.29 ± .11 43 4.60 ± .17 2.28 .13 .01 0.24 T3 108 4.27 ± .13 52 4.75 ± .18 4.68 .03^b .03 0.34 External motivation T2 96 4.52 ± .10 96 4.24 ± .10 4.28 .04^a .02 0.26 T3 99 4.21 ± .10 98 4.11 ± .10 .48 .49 .00 0.08 Identified motivation T2 96 5.36 ± .09 96 5.17 ± .09 2.01 .16 .01 0.17 T3 99 5.11 ± .10 98 4.97 ± .11 1.03 .31 .01 0.11 Intrinsic motivation T2 113 5.24 ± .14 42 4.88 ± .22 1.86 .18 .01 0.24 T3 112 4.97 ± .15 53 4.75 ± .21 .73 .39 .00 0.13 Enjoyment in PE T2 96 3.59 ± .09 96 3.50 ± .09 2.29 .13 .01 0.08 T3 99 3.46 ± .09 98 3.45 ± .09 .96 .33 .00 0.00 Knowledge T2 96 5.15 ± .12 96 5.21 ± .12 .12 .73 .00 0.04 T3 99 4.91 ± .13 98 4.98 ± .13 .15 .70 .00 0.05

a Intervention effect in favour of the IG.

b Intervention effect in favour of the CG.

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143 Table 25 Short- and Middle-Term Intervention Effects on Psychological Determinants of Physical Activity in Girls and Boys (Estimated Means (± SE),

Controlled for T1-Values and Baseline BMI Values)

Girls Boys

IG CG IG CG

Variable Time N M ± SE N M ± SE F p η² d N M ± SE N M ± SE F p η² d

Attitudes PA T2 80 5.99 ± .07 18 5.69 ± .15 3.46 .07 0.04 .41 36 5.75 ± .12 24 5.73 ± .15 .01 .92 .00 0.02 T3 79 5.94 ± .08 25 5.73 ± .14 1.71 .19 0.02 .27 36 5.86 ± .10 29 5.85 ± .11 .01 .94 .00 0.01 Attitudes PE T2 78 5.63 ± .07 18 5.62 ± .15 .01 .94 0.00 .01 35 5.18 ± .18 24 5.97 ± .21 7.94 .01^b .12 0.58 T3 78 5.41 ± .10 25 5.54 ± .18 .39 .53 0.00 -.09 35 5.58 ± .14 29 5.90 ± .15 2.46 .12 .04 0.29 Self-efficacy T2 77 4.36 ± .11 18 4.90 ± .23 4.63 .03^b 0.05 -.47 34 4.15 ± .23 25 4.37 ± .27 .40 .529 .007 0.15 T3 75 4.38 ± .13 24 4.94 ± .23 4.70 .03^b 0.05 -.44 33 4.00 ± .27 28 4.62 ± .29 2.45 .123 .041 0.40 External motivation T2 36 3.29 ± .13 65 3.44 ± .10 .33 .57 0.00 -.15 60 3.81 ± .12 31 3.55 ± .16 2.48 .12 .03 0.22 T3 38 3.09 ± .14 67 3.47 ± .10 .02 .89 0.00 -.34 61 3.72 ± .11 31 3.35 ± .16 2.97 .09 .03 0.27 Identified motivation T2 36 4.38 ± .14 65 4.21 ± .10 .99 .32 0.01 .18 60 4.63 ± .14 31 4.22 ± .19 3.06 .08 .03 0.35 T3 38 3.95 ± .15 67 4.07 ± .11 .43 .52 0.00 -.11 61 4.41 ± .13 31 4.11 ± .18 1.98 .16 .02 0.27 Intrinsic motivation T2 36 5.33 ± .15 65 5.18 ± .11 .60 .44 0.01 .13 60 5.39 ± .12 31 5.13 ± .17 1.63 .21 .02 0.23 T3 38 5.12 ± .17 67 5.05 ± .12 .12 .73 0.00 .06 61 5.12 ± .14 31 4.76 ± .19 2.33 .13 .03 0.27 Enjoyment in PE T2 36 5.71 ± .14 65 5.61 ± .11 .34 .56 0.00 .10 60 4.77 ± .17 31 4.46 ± .23 1.20 .28 .01 0.20 T3 38 5.10 ± .19 67 5.36 ± .14 1.19 .28 0.01 -.20 61 4.75 ± .17 31 4.26 ± .24 2.73 .10 .03 0.32 Knowledge T2 79 5.33 ± .16 18 4.72 ± .33 2.84 .10 0.03 .43 34 5.05 ± .26 24 4.97 ± .31 .04 .85 .00 0.05 T3 79 5.11 ± .16 25 4.88 ± .28 .52 .47 0.01 .16 33 4.64 ± .31 28 4.60 ± .34 .01 .93 .00 0.02

a Intervention effect in favour of the IG.

b Intervention effect in favour of the CG.

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144 Summary

The results concerning the within-group changes of students’ psychological determinants of physical activity revealed a mixed picture. Positive as well as negative significant short- and middle-term changes could be observed in the IG and in the CG. In the short-term, a significant increase in IG girls’ attitudes towards the health effects of physical activity took place and a significant increase in knowledge when analysing the entire IG independent of gender. Girls in the CG significantly increased their self-efficacy beliefs during this timeframe. During the follow-up period (T2-T3), a significant reduction was observed in several variables in the IG: The entire IG decreased their positive attitudes towards PE as well as the external, identified (this reduction was significant also in the gender separated analysis), and intrinsic motivation. Additionally, girls and boys of the CG as well as boys of the IG showed a reduction of the enjoyment during PE. Finally, the analysis of the middle-term changes revealed a positive development of students’ attitudes towards the health effects of physical activity as well as a reduction in the enjoyment of PE in the IG (gender independent analysis). The reduction of PE enjoyment was also significant in the IG boys in the gender separated analysis. The CG showed a reduction in the intrinsic motivation and the enjoyment in PE (gender independent analysis). This reduction in both variables was also significant in CG boys during the gender separated analysis. Finally, girls in the CG significantly increased their self-efficacy in the middle-term.

The short- and middle-term intervention effects comparing the IG with the CG revealed a rather negative influence of HealthyPEP lessons on the psychological determinants of physical activity. Except for an increase in the short-term external motivation in the entire IG only significant negative intervention effects were observed. The self-efficacy levels of the entire IG and the IG girls significantly decreased in the short- and middle-term and boys attitudes towards PE decreased in the short-term.