• Cardiorespiratory Profile and Performance Demands of Elite Hip-Hop Dancers: Breaking and New Style.

      Wyon, Matthew A; Harris, Julie; Adams, Faye; Cloak, Ross; Clarke, Francis A; Bryant, Janine (Scandmed, 2018-09-01)
      Dancers need to constantly maintain and develop their physiological capabilities to support their performances. Previously these physiological demands have been investigated only in traditional dance styles such as ballet and modern. The aim of this study was to examine the physiological demands of two types of hip-hop: new style and break dance. Nine female new style dancers (age 20±6 yrs, height 163.5±1.4 cm, mass 55.8±22 kg) and 9 male break dancers (age 23±4.2 yrs, height 178.2±5.7 cm, mass 62.1±7.7 kg) volunteered for the study. Each subject completed a maximal graded treadmill test and a dance performance routine, either new style (approx 1:45-2:30 min) or breaking (2 min). Breathe-by-breathe gas analysis and heart rate (HR) were collected by a portable gas analyser, and blood lactate (BLa) was measured at the end of the treadmill test and each routine. The male breaker dancers had significantly higher VO2 peak than other equivalent dancers in other genres, whilst the female new style dancers were similar to that previously reported for female dancers. Performance data showed significant differences between the two styles for VO2, HR, and BLa (p<0.001) and for VO2 and HR relative to individual maximal treadmill data (p<0.05). New style is more comparable to other theatrical dance genres, with a lower relative mean VO2 demand, whilst break dance is shorter in duration, allowing a higher cardiorespiratory demand and generating significant levels of blood lactate. This difference is also reflected in the dancers' cardiorespiratory profiles.
    • The effects of a home-based physical activity intervention on cardiorespiratory fitness in breast cancer survivors; a randomised controlled trial

      Lahart, Ian M.; Carmichael, Amtul R.; Nevill, Alan M.; Kitas, George D.; Metsios, George S.; Faculty of Education, Health and Wellbeing, Institute of Sport, University of Wolverhampton, Walsall, UK; Life & Health Sciences, Aston University, Birmingham, UK; Faculty of Education, Health and Wellbeing, Institute of Sport, University of Wolverhampton, Walsall, UK; Department of Research and Development, Dudley Group NHS Foundation Trust, Russells Hall Hospital, Dudley, UK; Faculty of Education, Health and Wellbeing, Institute of Sport, University of Wolverhampton, Walsall, UK (Routeledge, 2017-07-26)
      The aim of this current randomised controlled trial was to evaluate the effects of a home-based physical activity (PA) intervention on cardiorespiratory fitness in breast cancer survivors. Thirty-two post-adjuvant therapy breast cancer survivors (age = 52 ± 10 years; BMI = 27.2 ± 4.4 kg∙m2) were randomised to a six-month home-based PA intervention with face-to-face and telephone PA counselling or usual care. Cardiorespiratory fitness and self-reported PA were assessed at baseline and at six-months. Participants had a mean relative V̇O2max of 25.3 ± 4.7 ml∙kg−1∙min−1, which is categorised as “poor” according to age and gender matched normative values. Magnitude-based inference analyses revealed likely at least small beneficial effects (effect sizes ≥.20) on absolute and relative V̇O2 max (d = .44 and .40, respectively), and total and moderate PA (d = .73 and .59, respectively) in the intervention compared to the usual care group. We found no likely beneficial improvements in any other outcome. Our home-based PA intervention led to likely beneficial, albeit modest, increases in cardiorespiratory fitness and self-reported PA in breast cancer survivors. This intervention has the potential for widespread implementation and adoption, which could considerably impact on post-treatment recovery in this population.
    • Scaling children's waist circumference for differences in body size

      Nevill, Alan M; Duncan, Michael J.; Lahart, Ian M; Davies, Paul; Ramirez-Velez, Robinson; Sandercock, Gavin; Faculty of Education; Health and Wellbeing, University of Wolverhampton; Walsall Campus Walsall United Kingdom; Faculty of Health and Life Sciences; Coventry University; Coventry United Kingdom; Faculty of Education; Health and Wellbeing, University of Wolverhampton; Walsall Campus Walsall United Kingdom; Faculty of Education; Health and Wellbeing, University of Wolverhampton; Walsall Campus Walsall United Kingdom; Centro de Estudios en Medición de la Actividad Física (CEMA), Universidad del Rosario; Bogotá Cundinamarca Colombia; School of Biological Sciences; University of Essex; Colchester United Kingdom (Wiley, 2017-07-12)
      Objectives Both waist circumference (WC) and body size (height) increase with age throughout childhood. Hence, there is a need to scale WC in children to detect differences in adiposity status (eg, between populations and different age groups), independent of body size/height. Methods Using two culturally different samples, 1 English (10–15.9 years n = 9471) and 2 Colombian (14–15 years, n = 37,948), for WC to be independent of height (HT), a body shape index was obtained using the allometric power law WC = a.HTb. The model was linearized using log-transformation, and multiple regression/ANCOVA to estimate the height exponents for WC controlling for age, sex, and any other categorical/population differences. Results In both samples, the power-law height exponent varied systematically with age. In younger children (age 10–11 years), the exponent was approximately unity, suggesting that pre-pubertal children might be geometrically similar. In older children, the height exponent declined monotonically to 0.5 (ie, HT0.5) in 15+ year-olds, similar to the exponent observed in adults. UK children's height-adjusted WC revealed a “u” shaped curve with age that appeared to reach a minimum at peak-height velocity, different for boys and girls. Comparing the WC of two populations (UK versus Colombian 14–15-year-old children) identified that the gap in WC between the countries narrowed considerably after scaling for height. Conclusions Scaling children's WC for differences in height using allometric modeling reveals new insights into the growth and development of children's WC, findings that might well have been be overlooked if body size/height had been ignored.
    • Defining instances and limbs during performance of the standing turn

      Smith, Tina; Strike, Siobhan (Elsevier, 2017-07)
      Conventions have been reported to describe walking and turning gait. No such descriptions appear for the 180° standing turn and as such there are inconsistencies in the literature reporting on this movement. The complexity of explaining the standing turning motion, variation in number of steps when turning, and differing strategies used means conventions will make research reporting easier to comprehend and less likely for errors in interpretation. We propose definitions of the 180° standing turning motion and steps used to complete a turn for able-bodied and pathological populations to encourage consistency in reporting. It is recommended that the definitions be applied in future research on standing turns.
    • Effects of physical activity on the link between PGC-1a and FNDC5 in muscle, circulating Ιrisin and UCP1 of white adipocytes in humans: A systematic review

      Dinas, Petros C.; Lahart, Ian M.; Timmons, James A.; Svensson, Per-Arne; Koutedakis, Yiannis; Flouris, Andreas D.; Metsios, George S. (F1000, 2017-05-26)
      Background: Exercise may activate a brown adipose-like phenotype in white adipose tissue. The aim of this systematic review was to identify the effects of physical activity on the link between peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1a) and fibronectin type III domain-containing protein 5 (FNDC5) in muscle, circulating Irisin and uncoupling protein one (UCP1) of white adipocytes in humans. Methods: Two databases (PubMed 1966 to 08/2016 and EMBASE 1974 to 08/2016) were searched using an appropriate algorithm. We included articles that examined physical activity and/or exercise in humans that met the following criteria: a) PGC-1a in conjunction with FNDC5 measurements, and b) FNDC5 and/or circulating Irisin and/or UCP1 levels in white adipocytes. Results: We included 51 studies (12 randomised controlled trials) with 2474 participants. Out of the 51 studies, 16 examined PGC-1a and FNDC5 in response to exercise, and only four found increases in both PGC-1a and FNDC5 mRNA and one showed increased FNDC5 mRNA. In total, 22 out of 45 studies that examined circulating Irisin in response to exercise showed increased concentrations when ELISA techniques were used; two studies also revealed increased Irisin levels measured via mass spectrometry. Three studies showed a positive association of circulating Irisin with physical activity levels. One study found no exercise effects on UCP1 mRNA in white adipocytes. Conclusions: The effects of physical activity on the link between PGC-1a, FNDC5 mRNA in muscle and UCP1 in white human adipocytes has attracted little scientific attention. Current methods for Irisin identification lack precision and, therefore, the existing evidence does not allow for conclusions to be made regarding Irisin responses to physical activity. We found a contrast between standardised review methods and accuracy of the measurements used. This should be considered in future systematic reviews.
    • Physical Activity Levels of Adolescents with Type 1 Diabetes Physical Activity in T1D

      de Lima, Valderi Abreu; Mascarenhas, Luis Paulo Gomes; Decimo, Juliana Pereira; de Souza, William Cordeiro; Monteiro, Anna Louise Stellfeld; Lahart, Ian; França, Suzana Nesi; Leite, Neiva; Federal University of Paraná; Federal University of Paraná; Federal University of Paraná; University of Contestado; Universidade Federal do Parana; University of Wolverhampton; Universidade Federal do Parana; Federal University of Paraná (Human Kinetics, 2017-05)
      The aim of this study was to evaluate the level of physical activity and cardiorespiratory fitness in teenagers with type 1 diabetes mellitus (T1D) in comparison with healthy scholar participants. Total of 154 teenagers (T1D = 45 and CON = 109). Height, weight, cardiorespiratory fitness (VO2max), and the level of physical activity by the Bouchard’s Physical Activity Record were measured, and glycated hemoglobin (HbA1c) in T1D. The VO2max was lower in the T1D (38.38 ± 7.54) in comparison with the CON (42.44 ± 4.65; p < .05). The VO2max had correlation with the amount of time of moderate-to-vigorous physical activity (r = .63; p = .0001) and an inverse correlation with sedentary activities (r= -0.46; p = .006). In the T1D the levels of HbA1c had an inverse correlation with the amount of time of moderate-to-vigorous physical activity (r= -0.34; p = .041) and correlation with the BMI z-score (r = .43; p = .017). Only 37,8% of the participants in the T1D reached the adequate amount of daily moderate-to-vigorous intensity physical activity, in the CON 81,7% reached the WHO’s recommendation. Conclusion: T1D had less cardiorespiratory capacity then healthy controls, the teenagers of T1D with lower BMI z-score and that dedicated a greater time in moderate-to-vigorous intensity physical activity demonstrated a better glycemic control.
    • The Use of Recovery Strategies Among Participants of the Bupa Great North Run: A Cross-Sectional Survey

      Henderson, Sarah; Smith, Tina; Alexanders, Jenny; Shaw, Thomas; Smith, Lois; Nevill, Alan; Anderson, Anna (Human Kinetics, 2016-09-26)
      Objective: To investigate half marathon runners’ frequency of use of recovery strategies, perceptions regarding the most beneficial recovery strategy and reasons for using recovery strategies. Design: Cross-sectional survey. Participants: 186 participants of the 13.1 mile BUPA Great North Run 2013. Methods: A questionnaire was developed which required participants to indicate how frequently they used twelve different recovery strategies, identify which recovery strategy they believed to be most beneficial and rank six reasons for using recovery strategies in order of importance. Data was analysed using a Friedman non-parametric ANOVA and additional non-parametric tests. Results: All participants used recovery strategies. Stretching was the most commonly used recovery strategy (p < 0.001), whereas the use of nutritional supplements was the most commonly selected most beneficial recovery strategy. Over 50% of respondents indicated that they never used strategies such as kinesio tape (80%), hydrotherapy (78%) or ice baths (71%). A significant difference was observed between reasons for using recovery strategy (χ2 (5) = 292.29, p < 0.001). Reducing muscle tightness (rank 4.87) and reducing injury (rank 4.35), were the most frequently chosen most important reasons for using recovery strategies, minor sex and age differences in the responses were identified. Conclusion: Recovery strategy usage appears to be widespread among half marathon runners; however disparities exist between the frequency of use and perceived effectiveness of different recovery strategies. Further research in this area is needed to facilitate the development of recovery strategy guidelines which are both evidence-based and practically relevant.
    • Tibial impacts and muscle activation during walking, jogging and running when performed overground, and on motorised and non-motorised treadmills.

      Montgomery, G; Abt, G; Dobson, C; Smith, T; Ditroilo, M (Elsevier, 2016-09)
      Purpose To examine tibial acceleration and muscle activation during overground (OG), motorised treadmill (MT) and non-motorised treadmill conditions (NMT) when walking, jogging and running at matched velocities. Methods An accelerometer recorded acceleration at the mid-tibia and surface EMG electrodes recorded rectus femoris (RF), semitendinosus (ST), tibialis anterior (TA) and soleus (SL) muscle activation during OG, MT and NMT locomotion whilst walking, jogging and running. Results The NMT produced large reductions in tibial acceleration when compared with OG and MT conditions across walking, jogging and running conditions. RF EMG was small-moderately higher in the NMT condition when compared with the OG and MT conditions across walking, jogging and running conditions. ST EMG showed large and very large increases in the NMT when compared to OG and MT conditions during walking whilst SL EMG found large increases on the NMT when compared to OG and MT conditions during running. The NMT condition generated very large increases in step frequency when compared to OG and MT conditions during walking, with large and very large decreases during jogging and very large decreases during running. Conclusions The NMT generates large reductions in tibial acceleration, moderate to very large increases in muscular activation and large to very large decreases in cycle time when compared to OG and MT locomotion. Whilst this may decrease the osteogenic potential of NMT locomotion, there may be uses for NMTs during rehabilitation for lower limb injuries.
    • Opportunity through Sport

      Medcalf, Richard,; Biscomb, Kay. (Cambridge Scholars Publishing, 2015-10)
    • The effect of whole-body vibration on jump height and active range of movement in female dancers.

      Marshall, Lucille C; Wyon, Matthew A. (2012-03)
      Whole-body vibration (WBV) has been shown to have beneficial effects on strength and power indices in sedentary and moderately trained individuals. The aim of this study was to investigate the effect of 4 weeks of WBV on jump height, active range of motion (AROM), and leg anthropometry in conservatoire dance students. Seventeen female dancers were randomly assigned to a control or intervention group. The intervention group trained for 30 seconds per position at a 35-Hz frequency, 8-mm displacement in the first 2 weeks, and 40 seconds at 40 Hz for the final 2 weeks, whereas the control group carried out the same exercises but without vibration stimulation. A significant (p < 0.01) difference in the intervention group was noted over time for vertical jump and active ROM. No significant changes over time were noted in the anthropometric data. In conclusion, WBV can be used as a beneficial supplemental training intervention to increase jump and active flexibility in highly trained dancers without corresponding increases in relative anthropometric data.
    • Understanding the causes, prevention and treatment of osteoporosis (part 1):the structure of bone and the remodelling process

      Wyon, Matthew A.; Kumari, R; Hawkey, A; Metsios, G, (2011)
      Rheumatoid arthritis (RA) is a disabling disease characterised by chronic inflammation. moderate to high intensity exercise is recommended for the management of RA, although this is not always achievable due to pain caused by local inflammation. Identifying the current status of the swollen, tender joints and the patient’s perception of pain can be assessed using the ‘disease activity score’ (DAS28). Recently, vibration training has been shown to improve performance within healthy individuals, but has yet to be used in the treatment of RA. one female patient (age: 43yrs; height: 1.53m; mass: 48kg) with active RA was recruited for the current study. A sit and reach test was performed pre- and post- vibration. the DAS28 was recorded pre-, immediately post-, and 24hrs post- vibration. During vibration exposure, the patient performed three exercises (squat, lunge and calf raise), each for 30s with 60s recovery, at a frequency of 30Hz, and amplitude of 2mm. Results of the DAS28 showed no change in swollen joints 15 minutes post- vibration, but a reduction 24 hours post- vibration. there was no change in the number of tender joints 15 minutes post- training, but an increase 24 hours post- training. there was a 10% increase in the patient’s perception of health 15 minutes posttraining, with no change 24 hours post- training. there was also an increase (0.02m) in sit and reach test scores post- training. the current study suggests that a single bout of vibration training can have positive affects on patients’ perceived health, flexibility measures, and potentially reduce factors contributing to inflammation. However, the increased joint tenderness postvibration warrants further investigation, in a randomised controlled trial, to verify the effectiveness of vibration on inflammation and joint tenderness.
    • Prediction of VO2max from a new field test based on portable indirect calorimetry.

      Flouris, Andreas D.; Metsios, Giorgos S.; Famisis, Konstantinos; Geladas, Nikos; Koutedakis, Yiannis (Elsevier, 2010-01)
      We assessed the validity and reliability of the new 15m square shuttle run test (SST) for predicting laboratory treadmill test (TT) maximal oxygen uptake (VO(2 max)) compared to the 20 m multistage shuttle run test (MST) in 45 adult males. Thirty participants performed a TT and a SST once to develop a VO( 2max) prediction model. The remaining 15 participants performed the TT and MST once and the SST twice for cross-validation purposes. Throughout testing V O(2max) was determined via portable indirect calorimetry while blood lactate concentration was assessed at the fifth recovery minute. Comparisons of TT V O(2 max) (51.3+/-3.1 ml kg(-1)min(-1)) with SST measured (51.2+/-3.2 ml kg(-1)min(-1)) and predicted (50.9+/-3.3 ml kg(-1)min(-1)) V O(2 max) showed no differences while TT blood lactate was higher compared to SST (10.3+/-1.7 mmol vs. 9.7+/-1.7 mmol, respectively). In contrast, MST measured (53.4+/-3.5 ml kg(-1)min(-1)) and predicted (57.0+/-4.5 ml kg(-1)min(-1)) V O(2 max) and blood lactate (11.2+/-2.0 mmol) were significantly higher compared to TT. No test-retest differences were detected for SST measured and predicted V O(2 max) and blood lactate. It is concluded that the SST is a highly valid and reliable predictive test for V O(2 max).
    • Cardiorespiratory and immune response to physical activity following exposure to a typical smoking environment.

      Flouris, Andreas D.; Metsios, Giorgos S.; Jamurtas, Athanasios Z.; Koutedakis, Yiannis (BMJ Publishing Group, 2010)
      OBJECTIVE: Millions of non-smokers suffer daily passive smoking (PS) at home or at work, many of whom then have to walk fast for several minutes or climb a few sets of stairs. We conducted a randomised single-blind crossover experiment to assess the cardiorespiratory and immune response to physical activity following PS. DESIGN: Data were obtained from 17 (eight women) non-smoking adults during and following 30 minutes of moderate cycling administered at baseline and at 0 hour, 1 hour and 3 hours following a 1-hour PS exposure set at bar/restaurant PS levels. RESULTS: We found that PS was associated with a 36% and 38.7% decrease in mean power output in men and women, respectively, and that this effect persisted up to 3 hours (p<0.05). Moreover, at 0 hour almost all cardiorespiratory and immune variables measured were markedly reduced (p<0.05). For instance, FEV(1) values at 0 hour dropped by 10.2% in men and 10.8% in women, while IL-5 increased by 59.2% in men and 44% in women, respectively (p<0.05). At 3-hour mean values of respiratory quotient, mean power, perceived exertion, cotinine, FEV(1), IL-5, IL-6 and INFgamma in both sexes, recovery diastolic and mean arterial pressure, IL-4 and TNFalpha in men, as well as percentage predicted FEV(1) in women remained different compared to baseline (p<0.05). Also, some of the PS effects were exacerbated in less fit individuals. CONCLUSION: It is concluded that 1 hour of PS at bar/restaurant levels adversely affects the response to moderate physical activity in healthy non-smokers for at least 3 hours following PS.
    • Effect of seasonal programming on fetal development and longevity: links with environmental temperature.

      Flouris, Andreas D; Spiropoulos, Yiannis; Sakellariou, Giorgos J.; Koutedakis, Yiannis (Wiley, 2009)
      This study examined the effect of birth season on fetal development and longevity using two independent databases of all Greek citizens that were born (total: 516,874) or died (total: 554,101) between 1999 and 2003. We found significantly increased birth weight, gestational age, and longevity in individuals born during the autumn and winter seasons of the year. These individuals also demonstrated statistically significantly lower prevalence rates for fetal growth restriction and premature birth. Furthermore, we found that increased temperature at birth was associated with adverse effects on fetal development and longevity. In conclusion, our results show strong effects of season of birth on fetal development and longevity mediated, at least in part, by environmental temperature at time of birth.
    • Effect of a school-based intervention to promote healthy lifestyles in 7–11 year old children.

      Gorely, Trish; Nevill, Mary E.; Morris, John G.; Stensel, David J.; Nevill, Alan M. (BioMed Central Ltd., 2009)
      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.
    • Acute and short-term effects of secondhand smoke on lung function and cytokine production.

      Flouris, Andreas D.; Metsios, Giorgos S.; Carrillo, A. E.; Jamurtas, Athanasios Z.; Gourgoulianis, K.; Kiropoulos, Theodoros; Tzatzarakis, M. N.; Tsatsakis, A. M.; Koutedakis, Yiannis (American Thoracic Society, 2009)
      RATIONALE: The acute effect of secondhand smoke (SHS) on lung function and the duration of system disruption remain unknown. OBJECTIVES: To assess the SHS effects and their duration on lung function and inflammatory markers. METHODS: In a randomized single-blind crossover experiment data were obtained from 16 (8 women) nonsmoking adults at baseline and at 0, 1, and 3 hours after a 1-hour SHS exposure set at bar/restaurant SHS levels. MEASUREMENTS AND MAIN RESULTS: Serum and urine cotinine, lung function, and cytokines IL-4, IL-5, IL-6, tumor necrosis factor (TNF)-alpha, and IFN-gamma. At 0 hours most lung function parameters were significantly reduced (indicative: FEV(1), 4.3 +/- 0.4 vs. 3.8 +/- 0.3 L; FEV(1)/FVC, 0.9 +/- 0.1 vs. 0.8 +/- 0.1; P < 0.05) but at 3 hours they were at baseline levels. In contrast, cotinine (serum, 8.9 +/- 3.2 vs. 35.5 +/- 10.2 ng x ml(-1)), IL-4 (41.3 +/- 5.8 vs. 44.2 +/- 4.5 pg x ml(-1)), IL-5 (36.1 +/- 3.2 vs. 60.1 +/- 7.0 pg x ml(-1)), IL-6 (2.5 +/- 0.3 vs. 7.6 +/- 1.4 pg x ml(-1)) and IFN-gamma (0.3 +/- 0.2 vs. 0.6 +/- 0.2 IU x ml(-1)) at 3 hours were higher than at baseline (P < 0.05). IL-4 and TNF-alpha increased only in men, whereas IL-5, IL-6, and IFN-gamma were different between sexes after exposure (P < 0.05). Regression analyses revealed inverse associations of FEV(1) and FEV(1)/FVC ratio with IL-5 (P < 0.05) in men and with IL-5 (P = 0.01), IL-6 (P < 0.001), IFN-gamma (P = 0.034) and serum cotinine (P < 0.001) in women. CONCLUSIONS: We conclude that 1 hour of SHS exposure at bar/restaurant levels is accompanied by significant decrements on lung function and marked increases in inflammatory cytokines, particularly in men. More importantly, whereas most smoke-induced effects on lung function appear to recede within 60 minutes, inflammatory cytokines remain elevated for at least 3 hours after exposure to SHS.
    • Longitudinal preventive-screening cutoffs for metabolic syndrome in adolescents.

      Flouris, Andreas D.; Bouziotas, Constantin; Christodoulos, A. D.; Koutedakis, Yiannis (Macmillan, 2008-10)
      OBJECTIVE: To detect metabolic risk factor cutoff points in adolescence for the diagnosis of metabolic syndrome that develops at the age of 17 years (MS17). DESIGN: This study adopted a 6-year design incorporating four data collection time points (TPs). Volunteers were assessed prospectively at the ages of 12, 13, 14 and 17. PARTICIPANTS: A total of 210, 204, 198 and 187 schoolchildren volunteered at the first (TP(1)=12 years old), second (TP2=13 years old), third (TP3=14 years old) and fourth (TP4=17 years old) data collection TP, respectively. MEASUREMENTS: At each data collection TP, anthropometrical, biological and lifestyle data were obtained. Identical protocols were used for each assessment conducted by the same trained investigators. RESULTS: A total of 12% of the participants were diagnosed with MS17, the majority of them being boys (P<0.05). The prevalence of the syndrome increased directly with the degree of obesity. Using body mass index (BMI), adiposity and/or aerobic fitness levels in both genders, MS17 could be correctly diagnosed as early as TP1. No such cutoff points were found for high-density lipoprotein cholesterol, triglycerides, blood pressure and fasting plasma glucose levels. CONCLUSION: With respect to the data presented, it has been established that the calculated longitudinal preventive-screening cutoffs allow successful diagnosis of metabolic syndrome in adolescents using BMI, adiposity or aerobic fitness levels in both sexes. Adoption of such pediatric guidelines may help mitigate future increase in the prevalence of metabolic syndrome.
    • Differences in Physical Activity Levels Between White and South Asian Children in the United Kingdom

      Duncan, Michael; Woodfield, Lorayne; Al-Nakeeb, Yahya; Nevill, Alan M. (Human Kinetics, Inc., 2008)
      The purpose of this study was to compare physical activity levels between white and South Asian children in the UK. The data were obtained from 606, 11–14 year old schoolchildren (397 white; 209 Asian). Physical activity was assessed using the ‘four by one day’ recall questionnaire from which the time spent in moderate and vigorous physical activity was calculated. Boys were significantly more active than girls (p = .0001), and white children reported significantly greater physical activity than south Asian children (p = .001). Mean ± SD of time spent in moderate and vigorous activity was 90.2 ± 65.4 mins and 68.2 ± 49.3 mins for white and south Asian children and 103.5 ± 63.4 mins and 65.6 ± 53.5 mins for boys and girls respectively. These findings indicate that south Asian children are significantly less active than their white peers and there may be a need for specific interventions to target South Asian children particularly.
    • Criterion-related validity and test—retest reliability of the 20m Square Shuttle Test

      Metsios, Giorgos S.; Flouris, Andreas D.; Koutedakis, Yiannis; Nevill, Alan M. (Elsevier, 2008)
      We assessed validity and reliability of the new 20m square shuttle run test (SST) for predicting maximal oxygen uptake (˙VO2 max) and compared it with its predecessor, the 20m Multistage Shuttle Run Test (MST). In a repeatedmeasures randomised-block design, 74 healthy adult males performed the SST, the MST and a treadmill test (TT). To assess reliability, 40 of the total 74 volunteers were randomly-selected to perform the SST and MST twice. Unlike the SST (p > 0.05), mean predicted ˙VO2 max (pred˙VO2 max) from the MST was significantly increased from that measured during the TT (p < 0.05). The pred˙VO2 max from SST and MST correlated with TT ˙VO2 max at r = 0.95 (p < 0.001) and r = 0.63 (p < 0.001), respectively. Prediction error of SST was −0.3±3.3 ml kg−1 min−1 with a coefficient of variation of ±3.5%, while the equivalent values for MST were 4.2±7.3 ml kg−1 min−1 and ±7.4%. Mean test—retest pred˙VO2 max did not differ for both SST and MST (p > 0.05), while the corresponding test—retest correlation coefficients were r = 0.85 (p < 0.001) and r = 0.72 (p < 0.001). Reliability errors in 95% limits of agreement were 0.3±4.8 and 0.6±6.8 ml kg−1 min−1 while coefficients of variation were ±5.2% and ±6.8% for the SST and MST, respectively. It is concluded that SST is a more valid proxy than MST for predicting laboratory ˙VO2 max based on the current procedures, while both tests are sufficiently reliable in healthy male adults.
    • Can we use the Jackson and Pollock equations to predict body density/fat of obese individuals in the 21st century?

      Nevill, Alan M.; Metsios, Giorgos S.; Jackson, A.S.; Wang, J.; Thornton, J.; Gallagher, D. (Smith-Gordon, 2008)
      Objective: Jackson and Pollock’s (JP) ground-breaking research reporting generalized body density equations to estimate body fat was carried out in the late 1970s. Since then we have experienced an ‘obesity epidemic’. Our aim was to examine whether the original quadratic equations established by Jackson and co-workers are valid in the 21st century. Methods: Reanalyzing the original JP data, an alternative, more biologically sound exponential powerfunction model for body density is proposed that declines monotonically, and hence predicts body fat to rise monotonically, with increasing skin-fold thicknesses. The model also remains positive irrespective of the subjects’ sum-of-skinfold thicknesses or age. Results: Compared to the original quadratic model proposed by JP, our alternative exponential power-function model is theoretically and empirically more accurate when predicting body fat of obese subjects (sums of skinfolds >120mm). A cross-validation study on 14 obese subjects confirmed these observations, when the JP quadratic equations under estimated body fat predicted using dual energy x-ray absorptiometry (DXA) by 2.1% whereas our exponential power-function model was found to underestimate body fat by less than 1.0%. Otherwise, the agreement between the DXA fat (%) and the two models were found to be almost identical, with both coefficients of variation being 10.2%. Conclusions: Caution should be exercised when predicting body fat using the JP quadratic equations for subjects with sums of skinfolds>120 mm. For these subjects, we recommend estimating body fat using the tables reported in the present manuscript, based on the more biologically sound and empirically valid exponential power-function model.