Physical activity behaviour

In the following section, the results on the students’ physical activity behaviour (MVPA and exercise levels in and outside a sports club) are presented. First, the within-group changes are described and second, the specific intervention effects are stated. As already stated (see section 4.3.1.3.2), several problems occurred due to the low reliability values of the questionnaire. The consequences resulting from these low reliability values for the following results, are discussed in detail in section 4.3.3.

Chapter 4: Intervention Study

145 Within-group differences

The detailed results of the IG und the CG concerning the short- and middle term changes in MVPA and the minutes spent exercising in and outside a sports club are shown in table 26 and table 27.

Table 26 Short-Term Within-Group Differences in Physical Activity Levels

Variable T1

a Intervention effect in favour of the IG.

b Intervention effect in favour of the CG.

Table 27 Middle-Term Within-Group Differences in Physical Activity Levels

Variable T1

a Intervention effect in favour of the IG.

b Intervention effect in favour of the CG.

The short- and middle-term changes concerning the physical levels of the IG and the CG revealed mixed results. Regarding the MVPA levels the following changes were observed

Chapter 4: Intervention Study

146 (see Figure 15): In short-term, a significant increase occurred in IG boys (d = .36). In middle-term a significant increase was measured in both groups (IG: d = .19. CG: d = .30) in the gender independent analysis and in the CG girls (d = .47) during the gender separated examination. Additionally, in the follow-up period (T2-T3) a significant increase in IG girls was found.

Figure 15 Short- and Middle-Term Within-Group Developments of MVPA Levels in the IG and the CG Over the Five Month Investigation Period.

The items assessing the amount of exercise within a sports club showed that the students participated in several different sports in the clubs. The majority of the students played football (29.9%) followed by gymnastics (14.9%), and tennis (14.2%). Handball and dance were each carried out by 12.7% of the students and swimming and track and field athletics were carried out by 9.7% and 9% respectively. Information concerning the frequency and the number of minutes with which each training session was carried out was also provided. These numbers were calculated to receive the total sum of minutes that students spent exercising in the sports club every week. The results in this analysis revealed only a significant a short-term increase in the number of minutes IG boys spent exercising in a sports club (see Figure 16a).

No further significant changes could be observed. Overall, the number of minutes girls spent exercising in the sports club was similar in both groups: In the short-term the minutes remained stable. In the middle-term a small increase was observed in the IG whereas a decrease was measured in the CG girls. In boys, an increase in short- and middle term was observed in both groups.

The short- and middle-term within-group changes concerning the number of minutes students spent exercising outside the sports club are also shown in figure 16b. Regarding this domain, no short- and middle-term changes were observed. Nevertheless, based on the mean minutes measured, in girls a decrease in the short-time in both groups was observed. In the middle-term a decrease in the CG and an increase in the IG were revealed. In boys, the IG decreased

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Chapter 4: Intervention Study

147 the minutes spent exercising outside the sports club in the short-term whereas they showed an increase in the middle-term. The opposite was found in the CG boys. Concerning this variable, only one significant change was observed in the follow-up timeframe (T2-T3): the total CG decreased the number of minutes they spent exercising outside the sports club.

Figure 16 Short- and Middle-Term Within-Group Developments of Minutes Spent in and Outside the Sports Club in the IG and the CG Over the Five Month Investigation Period.

Between-group differences

The short- and middle-term intervention effects were examined (see Table 28). Based on the analysis of the entire study sample without differentiating on students’ gender, negative short-term intervention results occurred on the number of minutes students spent outside of a sports club (d = .74) whereas on the same item positive intervention effects were observed in the middle-term (d = .97). On the other variables assessing students’ physical activity levels no significant intervention could be observed. Also the observations based on the mean values do not bring out a clear picture concerning the tendencies of the intervention effects on students’

physical activity levels. Even the more differentiated gender separated analysis of the intervention effects on students’ physical activity could not provide clearer results. Only one positive middle-term intervention effect was revealed: IG boys spent a higher number of

Minutes of PA in the sports club (a)

IG CG

Minutes of PA outside the sports club (b)

IG CG

Chapter 4: Intervention Study

148 Table 28 Short- and Middle-Term Intervention Effects on Physical Activity in the Total, Girls, and Boys Group (Estimated Means (± SE), Controlled for T1-Values and Baseline BMI

a Intervention effect in favour of the IG.

b Intervention effect in favour of the CG.

Summary

Concluding, the study results concerning students’ physical activity levels show a rather mixed picture. Some of the assessed variables changed positively while other changed to a negative degree due to the intervention. As also shown by the retest-reliability results of the questionnaire, some of the items are not reliable and therefore the results based on them need to be interpreted with caution (see section 4.3.1.3.2).

4.3.2.3.3 Health and fitness outcomes