Psychology, Health & Medicine, 2015 Vol. 20, No. 4, 495–502, http://dx.doi.org/10.1080/13548506.2014.955034
Does exercise habit strength moderate the relationship between emotional distress and short-term memory in Malaysian primary school children? Nurul Ain Zainol and Hairul Anuar Hashim* Sport Science Unit, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Malaysia (Received 14 August 2013; accepted 4 August 2014) Purpose: We examined the moderating effects of exercise habit strength on the relationship between emotional distress and short-term memory in primary school children. Methods: The sample consisted of 165 primary school students (10–12 years old). Participants completed measures of emotional distress, exercise habit strength, and the Digit Span Test. Mid-year exam results were used as an indicator of academic performance. Structural equation modelling (SEM) was used to analyse the data. Results: The results of SEM revealed an acceptable fit for the hypothesised model. Exercise habit was positively associated with short-term memory, and better short-term memory was associated with better academic performance. However, although an inverse relationship was found between emotional distress and short-term memory, a positive association was found between exercise habit strength and emotional distress. Conclusion: The findings indicate that exercise habit is positively associated with cognitive ability and mediates the negative effect of distress. Keywords: stress; exercise habit strength; children; short-term memory; academic performance
Introduction Regulating the negative consequences of emotional distress is of utmost importance to ensure greater mental health in children and adolescents. School is one the main stressors in school-aged children and adolescents (Yusoff et al., 2011). A useful theoretical framework in understanding stress regulation process is the Transactional Model of Stress and Coping. This framework emphasises the sequential process of evaluating the situation and managing the specific external and/or internal demands that are perceived as exceeding the resources of the person (Lazarus & Folkman, 1984). In this regard, exercise is one of the recommended strategies in stress management. However, a study among Malaysian secondary school students has indicated that students who had stronger exercise habits tend to report higher levels of negative emotions (Hashim, Freddy, & Rosmatunisah, 2012). This contradictory and potentially misleading finding warrants further study. Firstly, it is speculated that the finding may be sample specific. Secondly, as examination performance is heavily influenced by other factors such as individual differences, we believe that factors mediating the relationship
*Corresponding author. Email: [email protected] © 2014 Taylor & Francis
496
N.A. Zainol and H.A. Hashim
of exercise habit strength with academic performance and emotional distress warrant further investigation. The main objectives of the present study were to (1) examine the profile of emotional distress in primary school children; (2) examine the associations among emotional distress, exercise habit strength, short-term memory and academic performance; (3) determine the moderating effect of exercise habit strength on the distress–memory relationship; (4) and determine the mediating effect of short-term memory on the exercise habit–academic performance and emotional distress–academic performance relationships. We hypothesised that a strong exercise habit is associated with lower stress levels and better short-term memory, whereas a weak habit is associated with higher stress levels and poorer short-term memory. Furthermore, short-term memory mediates the negative effects of stress on examination performance, and exercise habit strength contributes to better examination performance by enhancing short-term memory. Method Participants Participants were east Malaysia primary school students (n = 165) aged 10 (22%) and 11 (78%). Of the participants, 52% were male, and 48% were female. All participants were of Malay ethnicity. Participation was voluntary, and we obtained informed consent from the participants and their respective parents or legal guardians. Instruments Exercise habit strength questionnaire (Grove & Ortega, 2005) Exercise habit strength questionnaire (EHSQ) is an 18-item, four subscales measure of exercise habit strength. Each item is attached to a six-point Likert scale ranging from (1) “not true for me” to (6) “very true for me”. It has shown strong psychometric properties in previous studies involving adolescents (e.g. Hashim, Freddy, & Rosmatunisah, 2011). In the present sample, it exhibited adequate internal consistency: Patterned Action = .89, Automaticity = .89, Negative Consequences = .87 and Stimulus Cues = .91 as well as acceptable model-fit indices (χ2 = 324.40 df = 128, p < .001; χ2/df = 2.5; Root Mean Square Error of Approximation, RMSEA = .09) using confirmatory factor analysis. Short-term memory The Digit Span Test was used to measure short-term memory. Subjects were asked to memorise presented digits and write them down on the paper provided. One point was given for each correct response while a score of 0 was given when error was made with a maximum possible score of 17. Depression anxiety stress scale-21 (Lovibond & Lovibond, 1995) Emotional distress was measured using the Malay version of depression anxiety stress scale-21 (DASS-21; Ramli, Ariff, & Zaini, 2007). Each 21 items was rated on a scale of 0 (did not apply to me at all over the last week) to 3 (applied to me very much or most of the time over the past week). The severity-rating categories proposed by
Psychology, Health & Medicine
497
Lovibond and Lovibond (1995) are presented in Table 1. It has exhibited strong psychometric properties in previous studies (e.g. Hashim et al., 2011). The subscales α coefficients for the present sample were .66 (stress), .65 (anxiety) and .62 (depression). Marginal but acceptable model-fit indices (χ2 = 365.89 df = 187, p < .001; χ2/df = 1.9; RMSEA = .07) was also observed. Academic performance The measure of academic performance was based on the mid-year exam results. The results were obtained in the form of a single grade point average that represented an average of individual letter grades converted to numeric data (A = 1, B = 2, C = 3, D = 4, E = 5, F = 6). Using this scale, a lower GPA indicates better examination performance. Procedures Following the approval to conduct the study from the relevant authorities (University Human Ethics Committees, the Ministry of Education, and the principals of the participating schools), a short briefing regarding the study was conducted among the students. Students whose parents/guardians consented to their participation in the study were given the questionnaires to be completed in a classroom setting and were supervised by the first author. Students spent an average of 15 min completing the questionnaires. Statistical analysis Descriptive statistics, Pearson’s correlation coefficient and structural equation modelling (SEM) were used for data analyses. The maximum-likelihood estimation procedure and selected model-fit indices were used to compare the models. The selected fit indices and its desirable values (in brackets) were in the ratio of χ2/df (
Does exercise habit strength moderate the relationship between emotional distress and short-term memory in Malaysian primary school children? Nurul Ain Zainol and Hairul Anuar Hashim* Sport Science Unit, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Malaysia (Received 14 August 2013; accepted 4 August 2014) Purpose: We examined the moderating effects of exercise habit strength on the relationship between emotional distress and short-term memory in primary school children. Methods: The sample consisted of 165 primary school students (10–12 years old). Participants completed measures of emotional distress, exercise habit strength, and the Digit Span Test. Mid-year exam results were used as an indicator of academic performance. Structural equation modelling (SEM) was used to analyse the data. Results: The results of SEM revealed an acceptable fit for the hypothesised model. Exercise habit was positively associated with short-term memory, and better short-term memory was associated with better academic performance. However, although an inverse relationship was found between emotional distress and short-term memory, a positive association was found between exercise habit strength and emotional distress. Conclusion: The findings indicate that exercise habit is positively associated with cognitive ability and mediates the negative effect of distress. Keywords: stress; exercise habit strength; children; short-term memory; academic performance
Introduction Regulating the negative consequences of emotional distress is of utmost importance to ensure greater mental health in children and adolescents. School is one the main stressors in school-aged children and adolescents (Yusoff et al., 2011). A useful theoretical framework in understanding stress regulation process is the Transactional Model of Stress and Coping. This framework emphasises the sequential process of evaluating the situation and managing the specific external and/or internal demands that are perceived as exceeding the resources of the person (Lazarus & Folkman, 1984). In this regard, exercise is one of the recommended strategies in stress management. However, a study among Malaysian secondary school students has indicated that students who had stronger exercise habits tend to report higher levels of negative emotions (Hashim, Freddy, & Rosmatunisah, 2012). This contradictory and potentially misleading finding warrants further study. Firstly, it is speculated that the finding may be sample specific. Secondly, as examination performance is heavily influenced by other factors such as individual differences, we believe that factors mediating the relationship
*Corresponding author. Email: [email protected] © 2014 Taylor & Francis
496
N.A. Zainol and H.A. Hashim
of exercise habit strength with academic performance and emotional distress warrant further investigation. The main objectives of the present study were to (1) examine the profile of emotional distress in primary school children; (2) examine the associations among emotional distress, exercise habit strength, short-term memory and academic performance; (3) determine the moderating effect of exercise habit strength on the distress–memory relationship; (4) and determine the mediating effect of short-term memory on the exercise habit–academic performance and emotional distress–academic performance relationships. We hypothesised that a strong exercise habit is associated with lower stress levels and better short-term memory, whereas a weak habit is associated with higher stress levels and poorer short-term memory. Furthermore, short-term memory mediates the negative effects of stress on examination performance, and exercise habit strength contributes to better examination performance by enhancing short-term memory. Method Participants Participants were east Malaysia primary school students (n = 165) aged 10 (22%) and 11 (78%). Of the participants, 52% were male, and 48% were female. All participants were of Malay ethnicity. Participation was voluntary, and we obtained informed consent from the participants and their respective parents or legal guardians. Instruments Exercise habit strength questionnaire (Grove & Ortega, 2005) Exercise habit strength questionnaire (EHSQ) is an 18-item, four subscales measure of exercise habit strength. Each item is attached to a six-point Likert scale ranging from (1) “not true for me” to (6) “very true for me”. It has shown strong psychometric properties in previous studies involving adolescents (e.g. Hashim, Freddy, & Rosmatunisah, 2011). In the present sample, it exhibited adequate internal consistency: Patterned Action = .89, Automaticity = .89, Negative Consequences = .87 and Stimulus Cues = .91 as well as acceptable model-fit indices (χ2 = 324.40 df = 128, p < .001; χ2/df = 2.5; Root Mean Square Error of Approximation, RMSEA = .09) using confirmatory factor analysis. Short-term memory The Digit Span Test was used to measure short-term memory. Subjects were asked to memorise presented digits and write them down on the paper provided. One point was given for each correct response while a score of 0 was given when error was made with a maximum possible score of 17. Depression anxiety stress scale-21 (Lovibond & Lovibond, 1995) Emotional distress was measured using the Malay version of depression anxiety stress scale-21 (DASS-21; Ramli, Ariff, & Zaini, 2007). Each 21 items was rated on a scale of 0 (did not apply to me at all over the last week) to 3 (applied to me very much or most of the time over the past week). The severity-rating categories proposed by
Psychology, Health & Medicine
497
Lovibond and Lovibond (1995) are presented in Table 1. It has exhibited strong psychometric properties in previous studies (e.g. Hashim et al., 2011). The subscales α coefficients for the present sample were .66 (stress), .65 (anxiety) and .62 (depression). Marginal but acceptable model-fit indices (χ2 = 365.89 df = 187, p < .001; χ2/df = 1.9; RMSEA = .07) was also observed. Academic performance The measure of academic performance was based on the mid-year exam results. The results were obtained in the form of a single grade point average that represented an average of individual letter grades converted to numeric data (A = 1, B = 2, C = 3, D = 4, E = 5, F = 6). Using this scale, a lower GPA indicates better examination performance. Procedures Following the approval to conduct the study from the relevant authorities (University Human Ethics Committees, the Ministry of Education, and the principals of the participating schools), a short briefing regarding the study was conducted among the students. Students whose parents/guardians consented to their participation in the study were given the questionnaires to be completed in a classroom setting and were supervised by the first author. Students spent an average of 15 min completing the questionnaires. Statistical analysis Descriptive statistics, Pearson’s correlation coefficient and structural equation modelling (SEM) were used for data analyses. The maximum-likelihood estimation procedure and selected model-fit indices were used to compare the models. The selected fit indices and its desirable values (in brackets) were in the ratio of χ2/df (
