Effect of repeated sprints on postprandial endothelial function and triacylglycerol concentrations in adolescent boys

This study investigated if repeated, very short duration sprints influenced endothelial function (indicated by flow-mediated dilation) and triacylglycerol concentrations following the ingestion of high-fat meals in adolescent boys. Nine adolescent boys completed two, 2-day main trials (control and exercise), in a counter-balanced, cross-over design. Participants were inactive on day 1 of the control trial but completed 40 x 6 s maximal cycle sprints on day 1 of the exercise trial. On day 2 capillary blood samples were collected and flow-mediated dilation measured prior to, and following, ingestion of a high-fat breakfast and lunch. Fasting flow-mediated dilation and plasma triacylglycerol concentration were similar in the control and exercise trial (P>0.05). In the control trial flow-mediated dilation was reduced by 20% and 27% following the high-fat breakfast and lunch; following exercise these reductions were negated (main effect trial, P<0.05; interaction effect trial x time, P<0.05). The total area under the plasma triacylglycerol concentration versus time curve was 13% lower on day 2 in the exercise trial, compared to the control trial (8.65 (0.97) vs. 9.92 (1.16) mmol·L-1·6.5h, P<0.05). These results demonstrate that repeated 6 s maximal cycle sprints can have beneficial effects on postprandial endothelial function and triacylglycerol concentrations in adolescent boys

Attempted re-establishment of a sooty tern Onychoprion fuscatus breeding colony on Denis Island, Seychelles

Seychelles supports around three million nesting pairs of sooty terns. However, there have been recent declines and the colonies continue to face ongoing threats from habitat change and excessive commercial harvesting of their eggs, as well as potential threats by commercial fishing and climate change. A possible method to counter these threats is to re-establish breeding colonies on islands from which they have disappeared. An attempt was made to attract birds to a previously occupied island through habitat management, decoy birds and playback of recorded sooty tern calls. Habitat preparation involved predator eradication and tree removal to provide open ground with bare sandy areas and low herb vegetation. Overflying birds were attracted by broadcast calls, with some circling over and landing among the decoys. Large three-dimensional plastic models were superior to other models presented. This study demonstrated that large numbers of birds can be attracted by these means and that the birds then undertook behaviour associated with breeding, including egg laying by a few birds. However, after five seasons a breeding colony has not yet been established; one possible cause is the emergence of unexpected egg predators, common moorhen Gallinula chloropus and common myna Acridotheres tristis

Breakfast glycaemic index and exercise: combined effects on adolescents' cognition

The aim of the present study was to examine the combined effects of breakfast glycaemic index (GI) and a mid-morning bout of exercise on adolescents’ cognitive function. Participants were randomly allocated to a high or low GI breakfast group in a mixed research design, where each participant completed two experimental trials (exercise and resting). Forty-two adolescents (12.4±0.5 years old), undertook a bout of exercise (ten repeats of level one of the multi-stage fitness test; exercise trial) or continued to rest (resting trial) following consumption of either a high or low GI breakfast. A battery of cognitive function tests (visual search test, Stroop test and Sternberg paradigm) was completed 30 min before and 45 min following the exercise. Average heart rate during exercise was 170±15 beats.min-1. On the complex level of the Stroop test, response times improved across the morning following the low GI breakfast on both the exercise and resting trials, though the improvement was greatest on the exercise trial. However, response times only improved on the resting trial following the high GI breakfast (p = 0.012). On the 5 letter level of the Sternberg paradigm, response times improved across the morning following the low GI breakfast (regardless of exercise) and only on the exercise trial following the high GI breakfast (p = 0.019). The findings of the present study suggest that the combined effects of breakfast GI and exercise in adolescents depend upon the component of cognitive function examined. A low GI breakfast and mid-morning bout of exercise were individually beneficial for response times on the Sternberg paradigm, whereas they conferred additional benefits for response times on the Stroop test

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

Case Reports1. A Late Presentation of Loeys-Dietz Syndrome: Beware of TGFβ Receptor Mutations in Benign Joint Hypermobility

Background: Thoracic aortic aneurysms (TAA) and dissections are not uncommon causes of sudden death in young adults. Loeys-Dietz syndrome (LDS) is a rare, recently described, autosomal dominant, connective tissue disease characterized by aggressive arterial aneurysms, resulting from mutations in the transforming growth factor beta (TGFβ) receptor genes TGFBR1 and TGFBR2. Mean age at death is 26.1 years, most often due to aortic dissection. We report an unusually late presentation of LDS, diagnosed following elective surgery in a female with a long history of joint hypermobility. Methods: A 51-year-old Caucasian lady complained of chest pain and headache following a dural leak from spinal anaesthesia for an elective ankle arthroscopy. CT scan and echocardiography demonstrated a dilated aortic root and significant aortic regurgitation. MRA demonstrated aortic tortuosity, an infrarenal aortic aneurysm and aneurysms in the left renal and right internal mammary arteries. She underwent aortic root repair and aortic valve replacement. She had a background of long-standing joint pains secondary to hypermobility, easy bruising, unusual fracture susceptibility and mild bronchiectasis. She had one healthy child age 32, after which she suffered a uterine prolapse. Examination revealed mild Marfanoid features. Uvula, skin and ophthalmological examination was normal. Results: Fibrillin-1 testing for Marfan syndrome (MFS) was negative. Detection of a c.1270G > C (p.Gly424Arg) TGFBR2 mutation confirmed the diagnosis of LDS. Losartan was started for vascular protection. Conclusions: LDS is a severe inherited vasculopathy that usually presents in childhood. It is characterized by aortic root dilatation and ascending aneurysms. There is a higher risk of aortic dissection compared with MFS. Clinical features overlap with MFS and Ehlers Danlos syndrome Type IV, but differentiating dysmorphogenic features include ocular hypertelorism, bifid uvula and cleft palate. Echocardiography and MRA or CT scanning from head to pelvis is recommended to establish the extent of vascular involvement. Management involves early surgical intervention, including early valve-sparing aortic root replacement, genetic counselling and close monitoring in pregnancy. Despite being caused by loss of function mutations in either TGFβ receptor, paradoxical activation of TGFβ signalling is seen, suggesting that TGFβ antagonism may confer disease modifying effects similar to those observed in MFS. TGFβ antagonism can be achieved with angiotensin antagonists, such as Losartan, which is able to delay aortic aneurysm development in preclinical models and in patients with MFS. Our case emphasizes the importance of timely recognition of vasculopathy syndromes in patients with hypermobility and the need for early surgical intervention. It also highlights their heterogeneity and the potential for late presentation. Disclosures: The authors have declared no conflicts of interes

Effect of a school-based intervention to promote healthy lifestyles in 7–11 year old children.

Copyright 2009 Goreley et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/2.0/, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Background: Physical inactivity is recognised as a public health concern within children and interventions to increase physical activity are needed. The purpose of this research was to evaluate the effect of a school-based healthy lifestyles intervention on physical activity, fruit and vegetable consumption, body composition, knowledge, and psychological variables. Method: A non-randomised controlled study involving 8 primary schools (4 intervention, 4 control). Participants were 589 children aged 7–11 years. The intervention lasted 10 months and comprised a CD-rom learning and teaching resource for teachers; an interactive website for pupils, teachers and parents; two highlight physical activity events (1 mile school runs/walks); a local media campaign; and a summer activity wall planner and record. Primary outcome measures were objectively measured physical activity (pedometers and accelerometers) and fruit and vegetable consumption. Secondary outcomes included body mass index, waist circumference, estimated percent body fat, knowledge, psychological variables. Multi-level modelling was employed for the data analysis. Results: Relative to children in control schools, those in intervention schools significantly increased their total time in moderate-to-vigorous physical activity (MVPA) (by 9 minutes/day vs a decrease of 10 minutes/day), their time in MVPA bouts lasting at least one minute (10 minutes/day increase vs no change) and increased daily steps (3059 steps per day increase vs 1527 steps per day increase). A similar pattern of results was seen in a subset of the least active participants at baseline. Older participants in intervention schools showed a significant slowing in the rate of increase in estimated percent body fat, BMI, and waist circumference. There were no differences between groups in fruit and vegetable intake. Extrinsic motivation decreased more in the intervention group. Conclusion: The intervention produced positive changes in physical activity levels and body composition. It appeared to have little or no effect on consumption of fruit and vegetables. Schools are a suitable setting for the promotion of healthy lifestyles although more work, particularly focussed on dietary change, is needed in a variety of schools and social settings

Effect of the Great Activity Programme on healthy lifestyle behaviours in 7-11 year olds

The study investigated the effect of a school-based healthy lifestyles intervention on physical activity and dietary variables. In total 378 children (177 intervention, 201 control; age 9.75 &plusmn; 0.82 years (mean &plusmn; s)) took part in the 7-month intervention comprising: preparation for and participation in 3 highlight events (a dance festival, a walking event and a running event); an interactive website for pupils, teachers and parents; and vacation activity planners. Primary outcome measures were objectively measured physical activity (pedometers and accelerometers), endurance fitness and dietary variables. Multi-level modelling was employed for data analysis. The increase in physical activity was greater in the intervention group than the control group (steps: 1049 vs 632 daily steps each month; moderate to vigorous physical activity (MVPA) total: 4.6 min &middot; day-1 &middot; month-1 vs 1.3 min &middot; day-1 &middot; month-1; MVPA bouts: 5.4 min &middot; day-1 &middot; month-1 vs 2.6 min &middot; day-1 &middot; month-1; all P &lt; 0.05). The increase in multi-stage fitness test distance was greater for intervention participants (46 vs 29 m &middot; month-1 of intervention, group &times; month interaction, P &lt; 0.05). There were no differences between groups in dietary variables, body composition, knowledge of healthy lifestyles or psychological variables. Thus an intervention centred around highlight events and including relatively few additional resources can impact positively on the objectively measured physical activity of children

Physical activity and body composition outcomes of the GreatFun2Run intervention at 20 month follow-up

Background: Physical inactivity is recognised as a public health concern within children and interventions to increase physical activity are needed. GreatFun2Run was a school-based healthy lifestyles intervention that showed positive changes in physical activity levels and body composition immediately post-intervention. The purpose of this paper was to examine whether these changes in physical activity and body composition were maintained 18- 20 months after the intervention ended. Method: Participants (n = 589, aged 7-11 yrs) from 4 intervention and 4 control schools took part in the 10-month intervention, of which 421 (71%) were present for follow-up. The intervention comprised a CD-rom learning and teaching resource for teachers; an interactive website for pupils, teachers and parents; two highlight physical activity events (1 mile school runs/walks); a local media campaign; and a summer activity wall planner and record. Randomisation was not possible because of local media content. Outcome measures were objectively measured physical activity (pedometers and accelerometers) and body composition variables (body mass index, waist circumference, estimated percent body fat, and sum of skinfolds). Teacher interviews and participant focus groups were conducted. Multi-level modelling was employed for the data analysis. Results: Both control and intervention participants had increased their physical activity at follow-up but there was no group by time interaction (control: 2726 steps per day increase; intervention 3404 steps per day increase, p > .05). There were significant increases in estimated percent body fat, sum of skinfolds, waist circumference and body mass index (BMI) with increasing age. In the control group, there was evidence for a plateauing in the rate of change in all body composition variables with increasing age, except BMI. In contrast, significant interaction terms suggest that the rate of change in waist circumference, BMI and BMISDS continued to increase with age in the intervention group. Teacher interviews suggested that because of time pressures, competing resources, curriculum demands and staff changes the majority of teachers had not continued to use the resources. Conclusions: While the intervention initially produced positive changes in physical activity levels and body composition, these changes were not sustained once the intervention ended. Facilitating long-term health behaviour change in children remains a challenge