A randomised controlled trial of 1- versus 2-day per week formats of Nordic hamstring training on explosive athletic tasks in prepubertal soccer players

Purpose: This randomised controlled trial examined the effect of volume-equated programmes of Nordic hamstring exercise (NHE) training, executed at frequencies of 1- or 2-days per week, on explosive athletic tasks (30 m sprint, 15 m manoeuvrability and standing long jump [SLJ]) in male youth soccer players (mean age: 10.3 ± 0.5 years). Materials and methods: Players were divided into an experimental group (n=31) which was further subdivided into 1-day (n=16) and 2-days (n=15) per week training conditions, and a control group (n=14). Results: There were significant group-by-time interactions for 30-m sprint (p<0.001, d=0.6), SLJ (p=0.001, d=1.27) and 15 m manoeuvrability (p<0.001, d=0.61). The experimental group demonstrated small to moderate effect sizes in 30-m sprint (d=0.42, p=0.077), SLJ (d=0.97, p<0.001) and 15 m manoeuvrability (d=0.61, p<0.001). The control group showed small significant performance decrements or no change in these variables. There were no significant differences between the 1-day and 2-day training groups. In two of the three tests (30 m sprint, SLJ) the 2-day group demonstrated larger effect sizes. Conclusion: The NHE enhances explosive athletic task performance in prepubertal youth soccer players and there may be only small advantages to spreading training over two days instead of one

A Repeated Measures Experiment of Green Exercise to Improve Self-Esteem in UK School Children

Exercising in natural, green environments creates greater improvements in adult's self-esteem than exercise undertaken in urban or indoor settings. No comparable data are available for children. The aim of this study was to determine whether so called 'green exercise' affected changes in self-esteem; enjoyment and perceived exertion in children differently to urban exercise. We assessed cardiorespiratory fitness (20 m shuttle-run) and self-reported physical activity (PAQ-A) in 11 and 12 year olds (n = 75). Each pupil completed two 1.5 mile timed runs, one in an urban and another in a rural environment. Trials were completed one week apart during scheduled physical education lessons allocated using a repeated measures design. Self-esteem was measured before and after each trial, ratings of perceived exertion (RPE) and enjoyment were assessed after completing each trial. We found a significant main effect (F (1,74), = 12.2, p<0.001), for the increase in self-esteem following exercise but there was no condition by exercise interaction (F (1,74), = 0.13, p = 0.72). There were no significant differences in perceived exertion or enjoyment between conditions. There was a negative correlation (r = -0.26, p = 0.04) between habitual physical activity and RPE during the control condition, which was not evident in the green exercise condition (r = -0.07, p = 0.55). Contrary to previous studies in adults, green exercise did not produce significantly greater increases in self-esteem than the urban exercise condition. Green exercise was enjoyed more equally by children with differing levels of habitual physical activity and has the potential to engage less active children in exercise. © 2013 Reed et al

European fitness landscape for children and adolescents: updated reference values, fitness maps and country rankings based on nearly 8 million test results from 34 countries gathered by the FitBack network

Objectives (1) To develop reference values for health-related fitness in European children and adolescents aged 6–18 years that are the foundation for the web-based, open-access and multilanguage fitness platform (FitBack); (2) to provide comparisons across European countries. Methods This study builds on a previous large fitness reference study in European youth by (1) widening the age demographic, (2) identifying the most recent and representative country-level data and (3) including national data from existing fitness surveillance and monitoring systems. We used the Assessing Levels of PHysical Activity and fitness at population level (ALPHA) test battery as it comprises tests with the highest test–retest reliability, criterion/construct validity and health-related predictive validity: the 20 m shuttle run (cardiorespiratory fitness); handgrip strength and standing long jump (muscular strength); and body height, body mass, body mass index and waist circumference (anthropometry). Percentile values were obtained using the generalised additive models for location, scale and shape method. Results A total of 7 966 693 test results from 34 countries (106 datasets) were used to develop sex-specific and age-specific percentile values. In addition, country-level rankings based on mean percentiles are provided for each fitness test, as well as an overall fitness ranking. Finally, an interactive fitness platform, including individual and group reporting and European fitness maps, is provided and freely available online (www.fitbackeurope.eu). Conclusion This study discusses the major implications of fitness assessment in youth from health, educational and sport perspectives, and how the FitBack reference values and interactive web-based platform contribute to it. Fitness testing can be conducted in school and/or sport settings, and the interpreted results be integrated in the healthcare systems across Europe

Effects of activity pacing in patients with chronic conditions associated with fatigue complaints: a meta-analysis

A meta-analysis was conducted to (1) determine the effect of activity pacing interventions on fatigue, physical functioning and physical activity among patients with chronic conditions associated with fatigue complaints, and to (2) examine potential moderator effects of trial characteristics (components of intervention and amount of patient-provider contact). Six studies were included in the meta-analysis. Relevant content of the studies was extracted and rated on methodological quality. Random-effects modeling was used to pool data across studies. Medium (standardized mean difference =0.50) and marginal (standardized mean difference =0.34) effects were found for fatigue at post-treatment and follow-up respectively. Inconsequential effects were found for physical functioning and activity (standardized mean difference =0.08–0.30) at both assessment points. Subgroup analyses revealed components of intervention and amount of patient-provider contact were not the source of variance. Minimal patient-provider contact had an effect on fatigue comparable in magnitude to more intensive contact. This meta-analysis of activity pacing in patients with fatigue complaints suggests that activity pacing might have sustained beneficial effects on fatigue management, in particular on fatigue reduction. The divergence in effects for all outcomes suggests that alternative ways such as tailoring advice to individual’s behavior toward physical activity may be more successful

Oxygen Costs of the Incremental Shuttle Walk Test in Cardiac Rehabilitation Participants: An Historical and Contemporary Analysis

Background The incremental shuttle walk test (ISWT) is a standardised assessment for cardiac rehabilitation. Three studies have reported oxygen costs (VO2)/metabolic equivalents (METs) of the ISWT. In spite of classic rep- resentations from these studies graphically showing curvilinear VO2 responses to incremented walking speeds, linear regression techniques (also used by the American College of Sports Medicine [ACSM]) have been used to estimate VO2. Purpose The two main aims of this study were to (i) re- solve currently reported discrepancies in the ISWT VO2- walking speed relationship, and (ii) derive an appropriate VO2 versus walking speed regression equation. Methods VO2 was measured continuously during an ISWT in 32 coronary heart disease [cardiac] rehabilitation (CHD-CR) participants and 30 age-matched controls. Results Both CHD-CR and control group VO2 responses were curvilinear in nature. For CHD-CR VO2 = 4.4- e0.23 9 walkingspeed (km/h). The integrated area under the curve (iAUC) VO2 across nine ISWT stages was greater in the CHD-CR group versus the control group (p \ 0.001): & John P. Buckley [email protected] 1 (±86) mlkg-1min-1kmh-1; con- trol = 316 (±52) mlkg-1min-1kmh-1. Conclusions CHD-CR group vs. control VO2 was up to 30 % greater at higher ISWT stages. The curvilinear nature of VO2 responses during the ISWT concur with classic studies reported over 100 years. VO2 estimates for walking using linear regression models (including the ACSM) clearly underestimate values in healthy and CHD-CR par- ticipants, and this study provides a resolution to this when the ISWT is used for CHD-CR populations

Changes in self-esteem, ratings of perceived exertion and enjoyment in green exercise versus control.

<p>SE – Self esteem; measured using the Rosenberg scale (a lower score shows higher self-esteem) Δ<i>Score is pre-test minus post-test value.</i> RPE – Rating of Perceived Exertion; measured using Borg's 6–20 scale. Enjoyment – Score out of 120 measured using a visual analogue scale (a higher score shows greater enjoyment).</p

Self esteem pre- and post exercise in control and green exercise conditions.

<p>Self esteem; measured using the Rosenberg scale (a lower score shows higher self-esteem).</p

Validity and Reliability of Short-Term Heart-Rate Variability from the Polar S810

Purpose: To assess the validity and the reliability of short-term resting heart-rate variability (HRV) measures obtained using the Polar S810 heart-rate monitor and accompanying software. Methods: Measures of HRV were obtained from 5-min R to R wave (RR) interval data for 19 males and 14 females during 10 min of quiet rest on three separate occasions at 1-wk intervals using the Polar S8.10. Criterion measures of HRV were obtained simultaneously using the CardioPerfect (CP; Medical Graphics Corporation, St Paul, MN) 12-lead ECG module. Measures of validity of the Polar S810 were estimated by regression analysis, and measures of reliability of both. devices were estimated by analysis of change scores. Measures of the SD of normal-to-normal intervals (SDNN), the root mean square of successive differences (RMSSD), and the low-frequency (LF) and the high-frequency (HF) spectral power and their ratio (LF/HF) were analyzed after log transformation, whereas mean RR and LF and HF in normalized units were analyzed without transformation. Results: There were marginal differences between the Polar and the CP mean measures of HRV, and the uncertainty in the differences was small. The Polar S810 demonstrated high correlations (0.85-0.99) with CP for all measures of HRV indicating good to near-perfect validity. Except for the low- and the high-frequency normalized units, Polar S810 did not add any substantial technical error to the within-subject variability in the repeated measurements of HRV. Conclusion: HRV measures obtained with the Polar S810 and accompanying software have no appreciable bias or additional random error in comparison with criterion measures, but the measures are inherently unreliable over a 1-wk interval. Reliability of HRV from longer (e.g., 10 min) and/or consecutive 5-min RR recordings needs to be investigated with the Polar and criterion instruments. Copyright © 2008 by the American College of Sports Medicine