Fitness and academic performance in adolescents. The mediating role of leptin: DADOS study

Influence of Gender on Plasma Leptin Levels, Fat Oxidation, and Insulin Sensitivity in Young Adults: The Mediating Role of Fitness and Fatness

It is unknown how plasma leptin affects fat oxidation depending on sex in young adults. Therefore, the present cross-sectional study aimed to examine the associations of plasma leptin with resting fat oxidation (RFO), maximal fat oxidation during exercise (MFO), and insulin sensitivity, considering the different responses in men and women, and the mediating role of fatness and cardiorespiratory fitness (CRF). Sixty-five young adults (22.5 ± 4.3 years; body mass index = 25.2 ± 4.7 kg·m^-2, 23 females) participated in this study. Fasting plasma glucose, insulin, and leptin were analyzed. Variables related to insulin resistance (HOMA1-IR, HOMA2-IR), secretion (HOMA-%β), and sensitivity (HOMA-%S, QUICKI) were computed. RFO and MFO were determined through indirect calorimetry. A peak oxygen uptake (VO₂peak) test was performed until exhaustion after the MFO test. The MFO was relativized to body mass (MFO-BM) and the legs' lean mass divided by the height squared (MFO-LI). In men, leptin was negatively associated with MFO-BM and positively with HOMA-%β (p ≤ 0.02 in both). In women, leptin was positively associated with RFO and QUICKI, and negatively with MFO-BM (p < 0.05 in all). The association between leptin and MFO was mediated by CRF (p < 0.05), but not by fat mass (p > 0.05). Plasma leptin is associated with fat oxidation and insulin secretion/sensitivity, with different responses within each sex. The association between leptin and fat oxidation is mediated by cardiorespiratory fitness.

Working Memory in Overweight Boys during Physical Education Classes

This study examined the effect of small-sided football games (SSFG) and small-sided Ultimate Frisbee games (SSUFG) on working memory, response times, and feeling mood of boys with overweight. Twenty-eight boys (age 12.23 ± 1.58 years) participated in two trials during physical education lessons (20-min SSFG and 20-min SSUFG) in a counterbalanced, randomized crossover design. The response times and feeling mood were measured for all participants post-exercise through the Sternberg paradigm and feeling scale. For the response times, the paired samples t-test revealed a significantly better reaction time after SSUFG at the "One item level" of the Sternberg paradigm (p = 0.014, Hedges' g = 0.27, small effect) and (p = 0.010, Hedges' g = 0.74, medium effect), at "Three item level" (p = 0.000106, Hedges' g = 1.88, very large effect). The SSFG also showed vigor at the "Five item level" (p = 0.047, Hedges' g = 0.61, medium effect). For the feeling mood, the feeling score was significantly higher after the SSUFG session than the SSFG session and the increase in feeling scores observed after switching from SSFG to SSUFG was significantly different (p < 0.001) from the decrease observed in feeling scores after switching from SSUFG to SSFG. Therefore, the results of the study allow the teacher to introduce new sports and reflect on the motor tasks he or she proposes for boys with overweight during physical education classes.

Risk of depression mediates the association between cardiorespiratory fitness and academic performance in adolescent boys and girls: DADOS study

This study aims to analyze the mediating role of risk of depression in the association between cardiorespiratory fitness and academic performance in a sample of adolescents and to test the moderation effect of sex. A total of 263 adolescents (125 girls, 13.9 ± 0.3 years) from the DADOS (Deporte, ADOlescencia y Salud) study were included in the analysis. Cardiorespiratory fitness was assessed by the 20-m shuttle run test. Academic performance was assessed through the final academic grades and the test of educational abilities. Risk of depression was evaluated through the Behavior Assessment System for Children and Adolescents. Mediation analyses were performed to determine the direct and indirect associations between cardiorespiratory fitness, risk of depression, and academic performance. Indirect effects with confidence intervals not including zero were interpreted as statistically significant, and percentages of mediation were calculated in order to know how much of the association was explained by the mediation. Our findings indicated a significant mediating effect of risk of depression in the association between cardiorespiratory fitness with final grades in math, language, and grade point average (percentages of mediation: 26%, 53%, and 29%, respectively). These analyses were not moderated by sex (all confidence intervals included 0).

CONCLUSION

Risk of depression acts as a possible underlying mechanism in the association between cardiorespiratory fitness and academic grades in adolescents. Educational and health institutions could benefit from our findings since the promotion of higher cardiorespiratory fitness levels might reduce the risk of depression with potential benefits on adolescents' academic performance.

WHAT IS KNOWN

• Cardiorespiratory fitness is positively associated with academic performance in adolescents. Nevertheless, the psychological mechanisms underlying this association are poorly understood.

WHAT IS NEW

• Risk of depression mediates the association between cardiorespiratory fitness and academic performance in adolescents, independently of sex. • Our findings may improve the efficacy of mental health and educational programs by promoting the enhancement of cardiorespiratory fitness levels, which may reduce risk of depression with potential benefits on academic performance.

Physical fitness, physical activity and adiposity: associations with risk factors for cardiometabolic disease and cognitive function across adolescence

BACKGROUND

The cross-sectional associations between physical activity, physical fitness and adiposity with risk factors for cardiometabolic disease (particularly novel ones such as inflammatory cytokines) and cognitive function across the period of adolescence are not well understood. Additionally, novel physical activity metrics that summarise activity volume and intensity in a continuous manner have not been investigated in this context. Therefore, this study investigated the cross-sectional associations between physical activity, physical fitness and adiposity with risk factors for cardiometabolic disease and cognitive function. These associations were compared between younger and older adolescents.

METHODS

Seventy younger (11-12y, 35 girls) and 43 older (14-15y, 27 girls) adolescents volunteered to take part in the study. Physical fitness (multi-stage fitness test, MSFT) and adiposity (waist circumference) were determined, followed 7d later by resting blood pressure, a fasted blood sample (glucose, plasma insulin, IL6, IL10, IL15 and IL-1β concentrations) and a cognitive function test battery. Habitual physical activity was monitored via hip-worn accelerometers over this 7-d period and the average acceleration (activity volume), and intensity gradient (intensity distribution of activity) were determined.

RESULTS

Average acceleration and intensity gradient were negatively associated with mean arterial blood pressure (β = -0.75 mmHg, p = 0.021; β = -10 mmHg, p = 0.006, respectively), and waist circumference was positively associated with IL-6 concentration (β = 0.03%, p = 0.026), with stronger associations observed in older adolescents. Higher physical fitness (MSFT distance) was positively associated with anti-inflammatory IL-15 concentration (β = 0.03%, p = 0.038) and faster response times on the incongruent Stroop task (β = -1.43 ms, p = 0.025), the one-item level of the Sternberg paradigm (β = -0.66 ms, p = 0.026) and the simple (β = 0.43 ms, p = 0.032) and complex (β = -2.43 ms, p = 0.020) levels of the visual search test, but these were not moderated by age group.

CONCLUSIONS

The present study highlights the important role of physical activity (both the volume and intensity distribution) and physical fitness for cardio-metabolic health. Furthermore, the present study highlights the importance of physical fitness for a variety of cognitive function domains in adolescents, irrespective of age.

The relationship between physical fitness and academic performance among Chinese college students

OBJECTIVE

The present study aimed to examine the relationship between physical fitness and academic performance, after controlling for potential confounds.

PARTICIPANTS

The sample comprised 2,324 college students representing three Chinese universities.

METHODS

Physical fitness was measured using the Chinese National Student Physical Fitness Standard; academic performance (ie, Grade Point Average) and lifestyle behaviors were assessed using questionnaires. Academic performance and overall physical fitness were used to divide participants into three categories: low, moderate, and high.

RESULTS

Several physical fitness indicators systematically differed across the three academic performance categories. Additionally, overall physical fitness was positively associated with academic performance, even after controlling for the effects of lifestyle behaviors; those who belonged to the high overall physical fitness group had lower odds ratios of low academic performance than those belonging to the low overall physical fitness group.

CONCLUSIONS

Poor academic performance was related to low overall physical fitness . The probability of having poor academic performance was significantly lower among students with high physical fitness than those with low physical fitness.

Differences in Fitness and Academic Attainment between Obese, and Non Obese School-Age Adolescent Handball Players: An Explorative, Cross-Sectional Study

This study investigated differences in physical fitness and academic attainment in obese and non-obese adolescent handball players. A total of 31 males (age: 15.5 ± 1.2 years; body mass: 77.8 ± 17.7 kg; height: 1.71 ± 0.10 m; body mass index (BMI): 26.8 ± 6.9 kg/m2; body fat: 26.4 ± 6.34%) from the Qatar handball first division participated and were divided into two body fat percentage (%BF) groups (i.e., obese or non-obese). Anthropometrics (height, mass, BMI, and %BF) and physical performance testing ability (T-half test for change-of-direction (COD); squat jump (SJ), countermovement jump (CMJ), and 10 and 15 m sprints; medicine ball throw (MBT), and aerobic capacity (Yo-Yo Intermittent Recovery Test level 1 (Yo-Yo IR1)) were determined. Academic attainment was determined through grade point averages (GPA). Non-obese participants had superior performances in mathematics (p < 0.001) and science (p = 0.013), agility T-half test (p = 0.001), CMJ (p < 0.001), and 15 m sprint (p = 0.019). Correlations were found between T-half test and mathematics (r = 0.500) and science (r = 0.484). To conclude, obese school-age handball players have poorer fitness and academic performances than normal body weight adolescents.

Adiponectin, HOMA-Adiponectin, HOMA-IR in Children and Adolescents: Ouro Preto Study

OBJECTIVES

To examine the association and predictive capacity of adiponectin levels, HOMA-AD and HOMA-IR indexes with metabolic risk markers in children and adolescents.

METHODS

A cross-sectional study was conducted with 691 children and adolescents (7-14 y), of both sexes. Demographic (sex, age), anthropometric (weight, height, body mass index, waist circumference, body fat), biochemical [total cholesterol, high density lipoprotein (HDL), low density lipoprotein (LDL), triglycerides, fasting glycemia, insulin and adiponectin] and clinical parameters (arterial blood pressure) were analyzed.

RESULTS

In multiple linear regression models, metabolic risk were analyzed in relation to adiponectin levels, HOMA-AD and HOMA-IR. ROC curve analysis was used to define the cut-off for metabolic syndrome for each method studied. Adiponectin level was inversely correlated with weight (r = -0.12; p = 0.01), waist circumference (WC) (r = -0.12; p = 0.01), and triglycerides (r = -0.11; p = 0.02); it was directly correlated with HDL (r = 0.10; p = 0.03) only in the adolescents. In the final linear regression model, after adjustment, only triglycerides (p = 0.03) and HDL (p = 0.04) remained significant. However, HOMA-AD and HOMA-IR were associated with metabolic risk and were the most suitable methods for metabolic syndrome screening in both age groups. For children, independent variables explained 16.0% and 14.5% of HOMA-AD and HOMA-IR, respectively. For adolescents, R² was higher in HOMA-AD and HOMA-IR models (R²_adjusted = 31.9% and R²_adjusted = 29.6%, respectively).

CONCLUSIONS

HOMA-AD and HOMA-IR are better explained by metabolic markers than adiponectin levels.

Clustering of 24-h movement behaviors associated with cardiorespiratory fitness among adolescents: a latent class analysis

This study aimed to examine the clustering of 24-h movement behaviors (moderate to vigorous physical activity, screen time, and sleep duration) and their association with cardiorespiratory fitness among adolescents. We evaluated 561 adolescents (52.1% girls; mean age, 13.0 ± 1.0 years) from Florianópolis, Brazil. A 20-m shuttle run was used to assess cardiorespiratory fitness, while a questionnaire was used to measure 24-h movement behaviors. A latent class analysis was performed to identify the clustering of 24-h movement behaviors, while linear Bayesian mixed-effect regression models were applied to identify their association with cardiorespiratory fitness. Two classes were identified: unhealthy (10.4%), characterized as a high probability of practicing less than 300 min/week of moderate to vigorous physical activity, spending more than 4 h/day in front of screens, and sleeping less than 8 h/day; and healthy (89.6%), characterized by a high probability of practicing more than 420 min/week of moderate to vigorous physical activity, spending less than 2 h/day in front of screens, and sleeping 8-10 h/day. Adolescents in the healthy class had a higher cardiorespiratory fitness level than those in the unhealthy class. Most adolescents were grouped in the healthy class and had higher cardiorespiratory fitness levels than those in the unhealthy class. These results suggest that families and professionals should work toward creating healthier lifestyles for adolescents by increasing opportunities to practice moderate to vigorous physical activity, reduce screen time, and favor healthy sleep to increase their cardiorespiratory fitness levels. What is Known: • Moderate to vigorous physical activity, screen time, and sleep duration are positively, negatively, and inconsistently associated with cardiorespiratory fitness, respectively, when analyzed separately. • Little is known about the clustering of 24-h movement behaviors and how they are associated with cardiorespiratory fitness levels in adolescents. What is New: • The 24-h movement behaviors clustered into almost opposite classes among adolescents (healthy and unhealthy classes). • Adolescents in the healthy class had greater cardiorespiratory fitness levels than those in the unhealthy class.

Effect of football activity and physical fitness on information processing, inhibitory control and working memory in adolescents

Background

Whilst an acute bout of exercise has been shown to enhance subsequent cognition, including in adolescents, the effects of team games (of which Football is the most popular) has received little attention. Therefore, this study examined: the effect of an acute bout of outdoor Football activity on information processing, inhibitory control, working memory and circulating brain-derived neurotrophic factor (BDNF) in adolescents; the effect of physical fitness on cognition and; the moderating effect of physical fitness on the acute exercise responses.

Methods

Following familiarisation, 36 adolescents (16 girls) took part in two trials (60-min Football and 60-min seated rest) separated by 7-d in a counterbalanced, crossover design. Information processing and inhibitory control (Stroop Test), and working memory (Sternberg Paradigm) were assessed 30-min before exercise/rest and immediately, 45- and 90-min post-exercise/rest. Capillary blood samples were obtained before exercise/rest and up to 120-min post-exercise/rest. The median split of distance covered on the MSFT was used to divide the group into high- and low-fit groups.

Results

Performance on the cognitive function tasks was similar between Football and seated rest (trial*time interactions; all p > .05). However, the high-fit group had overall quicker response times on both levels of the Stroop Task and all three levels of the Sternberg Paradigm (main effect of fitness; all p < .001). Furthermore, the exercise-cognition relationship was moderated by physical fitness, with improvements in working memory response times seen post-exercise, only in the high-fit group (trial*time*fitness interaction, p < .05). Circulating BDNF was unaffected by the Football activity and physical fitness (p > .05).

Conclusion

The present study shows that higher levels of physical fitness are beneficial for cognitive function and provides novel evidence that an ecologically valid, and popular, form of exercise is beneficial for working memory following exercise, in high-fit participants only.