H-reflex depression (diminution of amplitude after a conditioning stimulus) is mediated presynaptically and therefore can help distinguish central versus peripheral mechanisms of fatigue. We examined the effects of a dynamic exercise protocol on H-reflex depression using two conditioning methods: homonymous conditioning (paired-pulse tibial nerve stimulation); and heteronymous conditioning (common peroneal nerve stimulation). Ten subjects performed dynamic contractions of the soleus muscle through 30° ankle range of motion. The concentric phase required a target force of 10% of maximum voluntary isometric contraction (MVIC) and the eccentric phase force target was 80% MVIC. Fatigue persisted for >20 min after cessation of the exercise. Compared with prefatigue values, the dynamic fatigue protocol did not increase presynaptic inhibition after either homonymous or heteronymous conditioning. Peak to peak amplitude of unconditioned H-reflexes was likewise unchanged despite a long term depression of muscle force (long duration fatigue). These results suggest that persistent fatigue after dynamic exercise is attributed to muscle changes and not altered spinal mechanisms.
Preeti D. Oza, Shauna Dudley-Javoroski and Richard K. Shields
Chung Gun Lee, Youngtae Cho and Seunghyun Yoo
Suicide is the leading cause of death among Korean adolescents. This study investigates the cross-sectional relations of physical activity with suicidal ideation and attempts in adolescents, simultaneously considering previously reported risk factors of suicide such as depression, stress, and body image.
This study used the 2007 Korea Youth Risk Behavior Web-based Survey (KYRBWS). Four hundred middle schools and 400 high schools in Korea were monitored, and 74,698 students completed the questionnaire. Logistic regression analysis was conducted to investigate the relationship between physical activity and suicidal ideation and attempts, progressively adjusting for body image, depression and stress.
After controlling for body image, stress, and depression, the significant relationship between physical activity and suicidal ideation disappeared, and the only remaining relationship was a positive relationship between frequent vigorous physical activity and suicide attempts. No sex differences were found after adjusting for all the variables.
Unlike the general expectation that physical activity protects adolescents from suicidal behaviors, the results from this study suggest that physical activity does not have protective effect. Korean adolescents who perform frequent vigorous physical activities are more likely to attempt suicide.
Catherine M. Sabiston, Rachel Jewett, Garcia Ashdown-Franks, Mathieu Belanger, Jennifer Brunet, Erin O’Loughlin and Jennifer O’Loughlin
The purpose of this study was to examine the longitudinal and unique association between number of years of team sport and individual sport participation during adolescence and depressive symptoms during early adulthood. Adolescents (n = 860) reported team sport and individual sport participation in each year of secondary school for five years. Participants reported depressive symptoms using the Major Depression Inventory three years after secondary school. Multivariate linear regression was performed to model the associations of sport participation with depressive symptoms while controlling for sex, age, parent education, and baseline depressive symptoms. In the final model, adolescents who consistently participated in team sport during high school reported lower depression scores in early adulthood (β = −.09, p = .02). Number of years of individual sport participation was not statistically significantly associated with depressive symptoms in early adulthood. Based on these findings, team sport participation may protect against depressive symptoms in early adulthood. If this finding is replicated, strategies should be implemented to encourage and maintain team sport participation during adolescence. Further research is needed to understand the mechanisms that link team sport participation to lower depression.
Geeske Peeters, Richard Hockey and Wendy Brown
This study was designed to compare theoretical strategies for changing physical activity (PA) in terms of their potential to reduce the incidence of chronic conditions in midage women: (1) whole population: +30 minutes/week in all, (2) high-risk: +60 minutes/week in the lowest 25% of the PA distribution, and (3) middle road: shift all those not meeting guidelines to a level commensurate with meeting guidelines.
10,854 participants (50–55 years in 2001) in the Australian Longitudinal Study of Women’s Health completed mail surveys in 2001, 2004, 2007, and 2010. PA was calculated as MET·minutes/week spent in walking, moderate and vigorous PA in the previous week. Incidence rates per 1000 person-years for diabetes, heart disease, hypertension, cancer, and depression were calculated for the actual distribution and after modeled shifts in PA.
The incidence rates were 10.6 for diabetes, 7.0 for heart disease, 30.7 for hypertension, 8.0 for cancer, and 28.4 for depression. Greater reductions in incidence were found for the middle road strategy than for the whole population and high-risk strategies, with reductions ranging from –6.3% for cancer to –12.3% for diabetes.
This theoretical modeling showed that a middle road strategy to increasing PA was superior to the whole population and high-risk strategies, in terms of reducing incidence rates of chronic conditions in middle-aged women.
Akitomo Yasunaga, Yukari Kawano, Yumiko Kamahori and Kyoko Noguchi
The purpose of the current study was to examine the association between the level of exercise behavior and individual and environmental factors related to exercise behavior among female Japanese undergraduate students.
The participants were 2482 female Japanese undergraduate students. Participants’ level of exercise behavior was measured by the stage of change to exercise in the transtheoretical model. Individual and environmental factors related to exercise behavior were assessed using body mass index, self-efficacy, social support, perceived positive and negative aspects of exercise, perceived neighborhood environment, attitude toward physical education lessons in childhood and puberty, and depression.
Scores for self-efficacy, social support, positive aspects of exercise, and perceived neighborhood environment were significantly higher among women who were more active compared with those who were inactive. On the other hand, scores for negative aspects of exercise and depression were greater among inactive women compared with those who were insufficiently active and/or active. In addition, past attitude toward exercise in primary school, junior high school, and high school was associated with current level of exercise behavior.
This cross-sectional study confirmed that psychosocial and environmental factors were closely associated with level of exercise behavior among female Japanese undergraduate students.
Lilian G. Perez, Elva M. Arredondo, Thomas L. McKenzie, Margarita Holguin, John P. Elder and Guadalupe X. Ayala
Greater neighborhood social cohesion is linked to fewer depressive symptoms and greater physical activity, but the role of physical activity on the relationship between neighborhood social cohesion and depression is poorly understood. The purpose of the study was to examine the effects of physical activity on the association between neighborhood social cohesion and depressive symptoms.
Multivariate logistic regression tested the moderation of self-reported leisure-time moderate-to-vigorous physical activity (LTMVPA) and active use of parks or recreational facilities on the association between neighborhood social cohesion and depressive symptoms among 295 randomly selected Latino adults who completed a face-to-face interview.
After adjusting for age, gender, and income, neighborhood social cohesion and depressive symptoms were inversely related (OR = 0.8; 95% CI: 0.5–1.2). Active use of parks or recreational facilities moderated the association between neighborhood social cohesion and depressive symptoms but meeting the recommendations for LTMVPA did not. Latinos who reported active use of parks or recreational facilities and higher levels of neighborhood social cohesion had fewer depressive symptoms than peers who did not use these spaces.
Future studies are needed to test strategies for promoting active use of parks or recreational facilities to address depression in Latinos.
Gary S. Goldfield, Katherine Henderson, Annick Buchholz, Nicole Obeid, Hien Nguyen and Martine F. Flament
To examine the association between volume and intensity of physical activity (PA) and depressive symptoms, anxiety, and body image in a large sample of adolescents in Ottawa and surrounding region.
A total of 1259 (n = 746 girls and n = 513 boys) students responded to surveys on leisure time PA, depressive symptoms, anxiety, and body image.
A dose response effect of intensity of PA and psychological distress was observed whereby those who performed greater bouts of vigorous PA exhibited better psychological adjustment than adolescents engaging in mild to moderate intensity activity. Gender impacted the results as vigorous PA was associated with reduced depression but not anxiety in boys, and reduced anxiety but not depression in girls. The positive association between total volume of PA and psychological functioning in the overall sample was no longer significant when gender was considered, except for reduced anxiety in girls.
Vigorous PA was associated with reductions in depressive symptoms, anxiety and improvements in body esteem in adolescents, but these associations were differentially influenced by gender. Future research is needed to elucidate the efficacy of vigorous PA as a treatment for mental health problems in male and female adolescents.
Toby G. Pavey, Nicola W. Burton and Wendy J Brown
There is growing evidence that regular physical activity (PA) reduces the risk of poor mental health. Less research has focused on the relationship between PA and positive wellbeing. The study aims were to assess the prospective associations between PA and optimism, in both young and mid-aged women.
9688 young women (born 1973–1978) completed self-report surveys in 2000 (age 22 to 27), 2003, 2006, and 2009; and 11,226 mid-aged women (born 1946–1951) completed surveys in 2001 (age 50–55) 2004, 2007, and 2010, as part of the Australian Longitudinal Study on Women’s Health. Generalized estimating equation models (with 3-year time lag) were used to examine the relationship between PA and optimism in both cohorts.
In both cohorts, women reporting higher levels of PA had greater odds of reporting higher optimism over the 9-year period, (young, OR = 5.04, 95% CI: 3.85–6.59; mid-age, OR = 5.77, 95% CI: 4.76–7.00) than women who reported no PA. Odds were attenuated in adjusted models, with depression accounting for a large amount of this attenuation (young, OR = 2.00, 95% CI: 1.57–2.55; mid-age, OR = 1.64 95% CI: 1.38–1.94).
Physical activity can promote optimism in young and mid-aged women over time, even after accounting for the negative effects of other psychosocial indicators such as depression.
Helmuth Haslacher, Matthias Michlmayr, Delgerdalai Batmyagmar, Thomas Perkmann, Elisabeth Ponocny-Seliger, Vanessa Scheichenberger, Thomas M. Scherzer, Sonja Nistler, Alexander Pilger, Peter Dal-Bianco, Johann Lehrner, Lukas Pezawas, Oswald F. Wagner and Robert Winker
A single nucleotide variant within the promoter of the 5-hydroxytryptamine1A (5HT1A) receptor, rs6295, is part of a binding site for the transcription factor NUDR (nuclear-DEAF-1-related). We aimed to ascertain whether the rs6295 mediates the effect of exercise on depressive mood in elderly endurance athletes. We prospectively enrolled 55 elderly athletes (marathon runners/bicyclists) and 58 controls. In a controlled, univariate model, an interaction between the [C]-allele and physical activity indicated that only among athletes, the variant resulting in an imperfect NUDR binding site was associated with a lower depression score. Hence, athletes presented with a significantly lower relative risk of achieving a suspicious depression score among carriers of at least one [C]-allele. Our results suggest that the positive effect of physical exercise on depressive mood might be mediated by the 5HT1A receptor and the extent of this protective effect seems to be enhanced by the [C]-allele of the rs6295 variant.
Melinda Asztalos, Greet Cardon, Ilse De Bourdeaudhuij and Katrien De Cocker
Sedentary behavior (including sitting) is negatively associated with physical health, independent from physical activity (PA). Knowledge on the associations with mental health is less elaborated. Therefore this study aims to investigate the relationship between sitting and 5 indices of mental health in adults (psychological distress, depression, anxiety, somatization, and sleeping problems), and between sitting interactions (sitting×gender, sitting×age, sitting×education, and sitting×PA) and these mental health indices.
A cohort of Belgian adults (25–64 years; n = 4344) provided self-reported data on sitting and PA and on 5 mental health indices. Cross-sectional associations were examined using multiple linear regression analyses.
Analyses adjusted for gender, age, education, and PA showed significant positive associations between sitting and the 5 mental health indices (P < .05). All associations were true for both men and women, and for low and high educated individuals, while some were only found in older individuals (somatization, P < .001) and those being insufficiently active (psychological distress, P = .007; depression, P = .002; and anxiety, P = .014).
More sitting seems to be associated with poorer mental health, independently of gender, age, education, and PA. Moderation analyses showed that these associations may differ according to age and PA levels.