Short-Term High-Intensity Rowing Ergometry Training Improves Rowing Performance Equally in Healthy Weight and Obese Adolescents

PURPOSE

Childhood obesity is a major health concern and physical activity is commonly proposed as an intervention strategy to combat the increasing prevalence of overweight and obesity in young people. The aim of this study was to examine the effect of high-intensity, supervised, rowing ergometer training on maximal and submaximal rowing performance in healthy weight and centrally obese adolescents (12-13 yr).

METHODS

Participants were randomized to either 6 wk of supervised rowing ergometry, comprising of 2 sessions per week with each session comprising of 2 × 3-min bouts of high-intensity rowing ergometry ( n = 57), or a control group who continued with their habitual activities ( n = 45). At baseline and follow-up, rowing performance was assessed via a submaximal test and a 3-min maximal test.

RESULTS

Six weeks of rowing ergometer training significantly improved maximal exercise performance; total distance rowed in a 3-min maximal effort improved by 19.7 m (2.7%) (time × group, P = 0.018) and produced a significant reduction in perceived effort in response to a set submaximal load (60 W) (time × group, P = 0.040). At baseline total distance rowed during the 3-min maximal test was significantly affected by body mass (main effect of body mass, P = 0.002), whereby a higher body mass was associated with enhanced rowing performance. However, the pattern of change over time was not different between healthy weight and centrally obese adolescents (time × group × waist centile, P = 0.577).

CONCLUSIONS

A 6-wk high-intensity rowing ergometry training intervention improved maximal rowing performance. This improvement was similar in healthy weight versus overweight and obese adolescents; yet overall overweight and obese adolescents had superior rowing performance compared to their healthy weight counterparts, suggesting that rowing may be an attractive exercise modality for interventions in overweight and obese young people.

Associations of Self-Control with Physical Activity, Physical Fitness, and Adiposity in Adolescents

The associations between self-control and objective measures of physical activity, physical fitness, and adiposity are yet to be explored in young people; this is a gap in the literature that the present study aimed to address. The study employed a cross-sectional design. A total of 101 young people participated in the study. Participants completed the Brief Self-Control Scale as a measure of trait self-control. Free-living physical activity was assessed using an ActiGraph GT3X + triaxial accelerometer, which was worn for 7 days. Participants also completed the 15-meter version of the multistage fitness test as a measure of physical fitness. For the assessment of adiposity, three criterion measures were used: body mass index (BMI), sum of skinfolds, and waist circumference. Data were analyzed using the glm function in the open access software R. Higher levels of trait self-control were associated with higher levels of physical fitness (measured by distance run on the multistage fitness test) and lower adiposity (BMI, waist circumference, and sum of skinfolds) in adolescents. There was a tendency for a positive association between self-control and time spent in vigorous physical activity, although this did not reach statistical significance. In a combined model, self-control was also associated with both physical fitness and waist circumference, with these effects independent of each other. These findings suggest that self-control is associated with healthy behaviors and characteristics in adolescents and is thus potentially an attractive target for future interventions aimed at increasing physical activity and physical fitness and reducing adiposity in this population.

Effects of a games-based physical education lesson on cognitive function in adolescents

Despite the importance of physical education (PE) lessons for physical activity in adolescents, the acute cognitive responses to PE lessons have not been explored; a gap in the literature that this study addresses. Following familiarisation, 76 (39 female) adolescents (12.2 ± 0.4 y) completed two trials (60 min games-based PE lesson and 60 min academic lesson) separated by 7-d in a counterbalanced, crossover design. Attention, executive function, working memory, and perception were assessed 30 min before, immediately post, and 45 min post-lesson in both trials. Participants were split into high-and low-fit groups based on a gender-specific median split of distance run on the multi-stage fitness test. Furthermore, participants were split into high and low MVPA groups based on a gender-specific median split of MVPA time (time spent >64% HR max) during the PE lesson. Overall, a 60 min games-based PE lesson had no effect on perception, working memory, attention, or executive function in adolescents (all p > 0.05) unless MVPA time is high. The physical activity-cognition relationship was moderated by MVPA, as working memory improved post-PE lesson in adolescents who completed more MVPA during their PE lesson (time*trial*MVPA interaction, p < 0.05, partial η2 = 0.119). Furthermore, high-fit adolescents displayed superior cognitive function than their low-fit counterparts, across all domains of cognitive function (main effect of fitness, all p < 0.05, partial η2 0.014–0.121). This study provides novel evidence that MVPA time moderates the cognitive response to a games-based PE lesson; and emphasises that higher levels of fitness are beneficial for cognitive function in adolescents.

Agreement and equivalence of estimated physical activity behaviours, using ENMO- and counts-based processing methods, for wrist-worn accelerometers in adolescents

The present study examined the agreement and equivalence between two physical activity processing methods. Data were obtained from 161 Hong-Kong adolescents (74 girls, age: 12.6 ± 1.7y). Participants wore an Actigraph GT3XBT on their non-dominant wrist for 7d. Time spent sedentary, and in light-(LPA), moderate-(MPA), vigorous-(VPA), and moderate-to-vigorous physical activity (MVPA) were calculated using different processing methods (proprietary counts and Euclidean Norm Minus One (ENMO)). Intraclass correlation coefficients (ICC) were used to examine absolute agreement (ICC2) and consistency (ICC3), and equivalence was assessed using pairwise equivalence tests. Using ENMO, sedentary time and VPA were higher, whereas all other behaviours were lower (compared to counts processing). Agreement ranged from poor (ICC2:0.42(Sedentary)) to moderate (ICC2:0.86(LPA)) and consistency ranged from moderate (ICC3:0.71(sedentary)) to good (ICC3:0.91(LPA)). Methods were not considered equivalent (all p > 0.05). Due to differences in the wear-time validation of processing methods, a sensitivity analyses (sub-sample with the same valid wear time for both methods (n = 56)), resulted in minimal change. Lack of agreement and equivalence between ENMO and counts processing methods suggests that the processing method significantly affects youth physical activity estimates.

Effect of adiposity and physical fitness on cardiometabolic risk factors in adolescents: A 2-year longitudinal study

Although risk factors for cardiometabolic diseases begin to present in young people, the association between physical fitness and adiposity with traditional and novel risk factors for cardiometabolic diseases across adolescence remains relatively unknown. Following ethical approval, fifty-two adolescents (age 11.6 ± 0.6 years; 32 girls) were recruited for a 2-years longitudinal study. Adiposity was assessed based on sum of skinfolds, waist circumference and body mass index, and physical fitness as distance run on the multi-stage fitness test (MSFT). Risk factors for cardiometabolic diseases (pro- and anti-inflammatory cytokines, plasma insulin, Homeostatic Model Assessment of Insulin Resistance - HOMA-IR, blood pressure) were measured following an overnight fast. Relationships between independent and response variables were analysed using multi-level modelling (final combined models were created using the stepwise backward elimination method). Plasma insulin concentration and HOMA-IR were positively associated with adiposity and inversely associated with distance run on the MSFT (all p < 0.05). The final combined models for plasma insulin concentration and HOMA-IR contained main effects for age, skinfolds and distance run on the MSFT. Levels of the anti-inflammatory cytokine IL-10 were inversely related to the sum of skinfolds (p = 0.046), whereas there was a trend for levels of the pro-inflammatory cytokine TNF-α to be positively related to the sum of skinfolds (p = 0.056). Adiposity and physical fitness are important, independent, determinants of metabolic health in adolescents. Furthermore, adiposity influences levels of pro- and anti-inflammatory cytokines in adolescence, with greater adiposity associated with a poorer inflammatory profile. The present study demonstrates an independent effect of physical fitness on metabolic health longitudinally across adolescence. It is therefore recommended that future work develops therapeutic interventions that reduce adiposity and enhance physical fitness in adolescents, to promote lifelong health.

Effect of 5-weeks participation in The Daily Mile on cognitive function, physical fitness, and body composition in children

The aim of the present study was to determine the effect of 5-weeks participation in The Daily Mile on cognitive function, physical fitness, and adiposity in primary school children. In a quasi-experimental study, one class from each school completed The Daily Mile (n = 44) or acted as a control group (n = 35). Baseline measures included cognitive function tests (Stroop test, Sternberg paradigm, Flanker task), physical fitness (multi-stage fitness test) and body composition (BMI percentile, waist:hip circumference, sum of skinfolds). The intervention group completed 5-weeks of The Daily Mile. Follow-up measurements were completed within 48-h of the last training session. Data were analysed via ANCOVA, examining between group differences at follow-up, controlling for baseline values. Response times on the complex Stroop test were faster at follow-up in the intervention group (Intervention: 1357 ms [1280–1400 ms]; Control: 1463 ms, [1410–1523 ms], d = 0.31, p = 0.048). There was no effect of The Daily Mile on the Sternberg paradigm or Flanker test. Physical fitness was greater at follow-up in the intervention group (Intervention: 880 m, [820–940 m]; Control: 740 m, [680–800 m], d = 0.39, p = 0.002). There was no effect of the intervention on adiposity. In conclusion, five-weeks of The Daily Mile enhanced inhibitory control and physical fitness in children, but did not affect working memory, attention, or adiposity.

Effect of two-weeks of school-based sprint training on physical fitness, risk factors for cardiometabolic diseases and cognitive function in adolescent girls: A randomized controlled pilot trial

Background

School-based physical activity interventions are accessible to most adolescents and could enhance adolescent cardiometabolic health and cognition; yet the feasibility and success of school-based physical activity interventions is understudied.

Methods

Sixteen adolescent girls (age: 11.7 ± 0.3 y; height: 1.58 ± 0.07 m; body mass: 45.5 ± 9.2 kg) were randomized to either an intervention (2-weeks sprint training; n = 8) or control group (continuation of regular physical activity levels; n = 8). Following familiarization, all participants completed baseline measurements including fasted and postprandial capillary blood samples, a battery of cognitive function tests (Stroop Test, Sternberg Paradigm and Flanker Task), and an assessment of physical fitness (20 m sprint and multi-stage fitness test). The intervention group completed 2-weeks progressive sprint training (3 sessions per week: week one 6 × 10 s sprints, week two 8 × 10 s sprints). Follow-up measurements were completed 48 h after the final sprint training session. Data were analyzed via ANCOVA to examine between group differences at follow-up whilst controlling for baseline score.

Results

Accuracy in the intervention group during the three-item Sternberg paradigm was greater when compared with the control group (Intervention: 99.6 ± 1.1%; Control: 97.7 ± 2.2%, p = 0.046). BDNF concentration was also higher in the intervention group at follow-up than control group (Intervention: 39.12 ± 9.88 ng.ml⁻¹; Control: 22.95 ± 9.13 ng.ml⁻¹, p < 0.001). There were no differences at follow-up between the intervention and control group for measures of cardiometabolic health (fasted cytokine concentrations or postprandial glycaemic and insulinaemic responses) or on the Stroop Test or Flanker Task (all p > 0.05). However, the intervention group reported enjoying the sprint training and that they found the sessions valuable.

Conclusion

Two-weeks sprint interval training in a school-setting enhanced working memory and increased concentrations of BDNF in adolescent girls. The intervention was deemed enjoyable and worthwhile by the adolescent girls and thus the longer-term implementation of such an intervention should be examined.

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.

Effect of acute football activity and physical fitness on glycaemic and insulinaemic responses in adolescents

The present study examined the metabolic responses to an acute bout of football and the overall and moderating role of physical fitness on these responses, in adolescents. Thirty-six adolescents (16 girls, 20 boys; 12.6±0.5 y) completed two trials (60-min football and 60-min seated rest) separated by 7-d. Capillary blood samples were taken at baseline (60-min prior to exercise/rest), immediately, 30- and 60-min post-exercise and 30-, 60- and 120-min following a standardised lunch (1.5-, 2- and 3-h post-exercise), for the determination of blood glucose and plasma insulin concentrations. The median split of distance covered on the multi-stage fitness test was used to define high- and low-fit groups. Overall plasma insulin tAUC following lunch was lower in high-fit participants compared to low-fit (high-fit: 3784.2±1653.1 pmol·L^-1x120min, low-fit: 6457.3±3290.7 pmol·L^-1x120min; p<0.001), although there was no acute effect of the football session (p>0.05). Football reduced blood glucose concentration 1-h post-exercise compared to control (exercise: 3.8±0.6 mmol·L^-1, rest: 4.6±0.8 mmol·L^-1; p<0.001), but this was similar for the high- and low-fit participants (p>0.05). Blood glucose tAUC was not affected by exercise or physical fitness (p>0.05). These data emphasise the importance of physical fitness for metabolic health in adolescents, as well as the utility of football as a popular form of games-based activity for improving glucose regulation.

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.

Multi-Stage Fitness Test Performance, V ˙ O2 Peak and Adiposity: Effect on Risk Factors for Cardio-Metabolic Disease in Adolescents

The role of physical activity in determining the metabolic health of adolescents is poorly understood, particularly concerning the effect on low-grade chronic inflammation (chronic elevation of pro-inflammatory cytokines IL-1β, IL-6, TNF-α and acute phase protein CRP, which is implicated in the etiology of atherosclerosis) and anti-inflammatory mediators such as IL-10. Furthermore, there is limited information on the mediating effects of performance on the multi-stage fitness test (MSFT), V˙O₂ peak and adiposity on risk factors for cardio-metabolic disease in adolescents.

Purpose: To examine the effect of performance on the MSFT, V˙O₂ peak and adiposity on risk factors for cardio-metabolic diseases in adolescents.

Methods: Following ethical approval, 121 adolescents (11.3 ± 0.8 year) completed the study. Risk factors for cardio-metabolic disease (circulating inflammatory cytokines, blood glucose and plasma insulin concentrations) was assessed using a fasted capillary blood sample. Participants were separated into quartiles based upon distance ran during the MSFT, the blood lactate response to submaximal exercise, V˙O₂ peak (determined during an uphill graded treadmill test), and adiposity (determined as the sum of four skinfolds). The blood lactate response to submaximal exercise and V0₂ peak were measured in a sub-group of participants. Data were analyzed using two-way between-subjects ANCOVA and multiple linear regression.

Results: Participants with the lowest performance on the MSFT had higher blood concentrations of IL-6 (3.25 ± 0.25 pg mL^-1) and IL-1β (4.78 ± 0.54 pg mL^-1) and lower concentrations of IL-10 (1.80 ± 0.27 pg mL^-1) when compared with all other quartiles (all p < 0.05). Yet, when categorized into V˙O₂ peak quartiles, no differences existed in any of the inflammatory mediators (all p > 0.05). Performance on the MSFT was the only predictor of IL-6 (β = -0.291, p = 0.031), IL-1β (β = -0.405, p = 0.005), IL-10 (β = 0.325, p = 0.021) and fasted blood glucose (β = -0.545, p < 0.001) concentrations. Adiposity was the only predictor of plasma insulin concentration (β = 0.515, p < 0.001) and blood pressure (diastolic: β = 0.259, p = 0.042; mean arterial pressure: β = 0.322, p = 0.011).

Conclusion: Enhanced performance on the MSFT, but not V˙O₂ peak, was associated with a favorable inflammatory profile in adolescents; whilst adiposity adversely affected plasma insulin, diastolic and mean arterial blood pressure. These findings demonstrate that enhancing performance on the MSFT and maintaining a healthy body composition are a potential therapeutic intervention for the attenuation of risk factors for cardio-metabolic diseases in adolescents.

Cytokine, glycemic, and insulinemic responses to an acute bout of games-based activity in adolescents

An acute bout of endurance exercise in adults stimulates a same‐day anti‐inflammatory response which may affect low‐grade chronic inflammation and insulin resistance and benefit cardio‐metabolic health. The anti‐inflammatory responses to intermittent games‐based exercise and to exercise in young people beyond 2 hours post‐exercise are unknown. Thus, the purpose of the present study is to examine the anti‐inflammatory, glycemic and insulinemic response to games‐based activity in adolescents. Following ethical approval and familiarization, 39 adolescents (12.3 ± 0.7 years) completed an exercise (E) and rested (R) trial in a counterbalanced, randomized crossover design. Following a standardized breakfast, participants completed 1‐hour games‐based activity. Capillary blood samples were taken at baseline, immediately and 1 hour post‐exercise, and 30, 60 and 120 minutes following a standardized lunch. A final blood sample was taken the next morning. Data were analyzed using repeated measures ANOVA. IL‐6 concentration was higher on day one of the exercise trial (E:3.4 ± 0.4, R:2.7 ± 0.4 pg/mL; P = 0.006), as was the anti‐inflammatory IL‐6:TNF‐α ratio (E:5.53 ± 0.93, R:3.75 ± 0.45; P = 0.027). Levels of the anti‐inflammatory cytokine IL‐10 increased on day two of the exercise trial (E:2.11 ± 0.23, R:1.66 ± 0.16 pg/mL; P = 0.032). Insulin sensitivity was enhanced on the exercise trial with a reduction in iAUC following the standardized lunch (E:2310 ± 834, R:3122 ± 1443 mU/L × 120 minutes; P < 0.001). Games‐based activity stimulated an anti‐inflammatory response up to 24 hours post‐exercise and improved insulin sensitivity in response to a standardized meal in healthy adolescents. These novel findings suggest that games‐based activity is an ecologically valid mode of exercise to elicit beneficial effects on cardio‐metabolic risk factors in young people.

High intensity intermittent games-based activity and adolescents' cognition: moderating effect of physical fitness

BACKGROUND

An acute bout of exercise elicits a beneficial effect on subsequent cognitive function in adolescents. The effect of games-based activity, an ecologically valid and attractive exercise model for young people, remains unknown; as does the moderating effect of fitness on the acute exercise-cognition relationship. Therefore, the aim of the present study was to examine the effect of games-based activity on subsequent cognition in adolescents, and the moderating effect of fitness on this relationship.

METHODS

Following ethical approval, 39 adolescents (12.3 ± 0.7 year) completed an exercise and resting trial in a counterbalanced, randomised crossover design. During familiarisation, participants completed a multi-stage fitness test to predict VO₂ peak. The exercise trial consisted of 60-min games-based activity (basketball), during which heart rate was 158 ± 11 beats∙min^- 1. A battery of cognitive function tests (Stroop test, Sternberg paradigm, trail making and d2 tests) were completed 30-min before, immediately following and 45-min following the basketball.

RESULTS

Response times on the complex level of the Stroop test were enhanced both immediately (p = 0.021) and 45-min (p = 0.035) post-exercise, and response times on the five item level of the Sternberg paradigm were enhanced immediately post-exercise (p = 0.023). There were no effects on the time taken to complete the trail making test or any outcome of the d2 test. In particular, response times were enhanced in the fitter adolescents 45-min post-exercise on both levels of the Stroop test (simple, p = 0.005; complex, p = 0.040) and on the three item level of the Sternberg paradigm immediately (p = 0.017) and 45-min (p = 0.008) post-exercise.

CONCLUSIONS

Games-based activity enhanced executive function and working memory scanning speed in adolescents, an effect particularly evident in fitter adolescents, whilst the high intensity intermittent nature of games-based activity may be too demanding for less fit children.