The impact of long haul travel on the sleep of elite athletes.

In order to manage and implement strategies to alleviate the symptoms of jet lag it is essential to assess the impact of jet lag in athletes. The aim of this study was to assess the impact of long haul eastward travel on elite athletes' (n = 7 elite national track cyclists; male n = 3, and female n = 4) sleep. The athletes' sleep was monitored before, during and after travel using both actigraphy and self-report measures. Participants wore an activity monitor for 5 days prior to travel, during the long haul travel and 5 days upon arrival at their destination and completed a daily online sleep diary Actigraphy highlighted significant reductions in time in bed, total sleep time and sleep efficiency (%) due to long haul eastward travel, particularly in the 48 h after travel. Sleep diary data exhibited significant reductions in time in bed, total sleep time, sleep efficiency, sleep quality and a significant increase in fatigue going to bed as a result of long haul eastward travel. In order to facilitate the development of interventions to reduce the symptoms and severity of jet lag objective and subjective assessments of sleep should be coupled with assessments of chronotype and perceived sleep need.

BMI is dead; long live waist-circumference indices: But which index should we choose to predict cardio-metabolic risk?

BACKGROUND AND AIMS: There is growing evidence that Body Mass Index (BMI) is unfit for purpose. Waist circumference (WC) indices appear to be the preferred alternative, although it is not clear which WC index is optimal at predicting cardio-metabolic risk (CMR) and associated health outcomes. METHODS AND RESULTS: We obtained a stratified random probability sample of 53,390 participants from the Health Survey for England (HSE), 2008-2018. The four available CMR factors were; high-density lipoproteins (HDL) cholesterol, glycated haemoglobin (HbA1c), systolic (SBP) and diastolic blood pressure (DBP). Strength of association between the four cardio-metabolic risk factors and competing anthropometric indicators of weight status [BMI, Waist-to-height ratio (WHTR), unadjusted WC, and a new WC index independent of height, WHT·5R = WC/height0.5] was assessed separately, using simple correlations and ANCOVAs, and together (combined) using MANCOVA, controlling for age, sex and ethnicity. Centile curves for the new index WHT·5R = WC/height0.5were also provided. CONCLUSIONS: Waist-circumference indices were superior to BMI when explaining/predicting our CMR factors, before and after controlling for age, sex and ethnicity. No single WC index was consistently superior. Results suggest that WHTR is the strongest predictor of HbA1c, confirming that shorter individuals are at great risk of diabetes. The most appropriate WC index associated with blood pressure was WHT·5R for DBP, or unadjusted WC for SBP. Given HDL cholesterol is independent of height, the best predictor of HDL was WHT.5R. Clearly, "no one size fits all!". MANCOVA identified WHT·5R to be the best single WC index associated with a composite of all four CMR factors.

Common mental disorders among Irish jockeys: prevalence and risk factors.

OBJECTIVE: Jockeys compete in a sport, horseracing, renowned for its physical and psychological demands. Previous research has identified that common mental disorders (CMDs) may be prevalent among this unique population of athletes. The aim of the present study was to further explore the prevalence of CMDs among jockeys and to test for associations with potential risk factors. METHODS: An anonymous survey was distributed to professional jockey online. Self-report screening tools for four CMDs (psychological distress, depression, generalized anxiety, and adverse alcohol use) were included alongside predictor variables from questionnaires assessing for burnout, career satisfaction, social support, and the contemplation of retirement. Binary logistic regression was used to explore associations between CMDs (present versus not present) and risk factors. Eighty-four professional jockeys completed the questionnaire (response rate = 52%). RESULTS: In total, 79% of jockeys met the threshold for at least one CMD. Prevalence (%) of CMD varied as follows: adverse alcohol (61%), depression (35%), generalized anxiety (27%), and psychological distress (19%). Burnout, career (dis)satisfaction, lower levels of social support, and the contemplation of retirement increased the odds of meeting the criteria for CMDs. CONCLUSION: The findings indicate that jockeys report CMD symptoms at comparable rates to athletes in other sports. The study was the first to highlight potential risk factors as predictors of CMDs among jockeys, including burnout, career satisfaction, and the current contemplation of retirement. Screening tools for the risk factors demonstrated may, therefore, provide useful in the early identification of CMDs among jockeys. The development of jockey-specific assessment tools, education programmes, and interventions may help better understand and support the mental health of jockeys.

The effect of intermittent running on biomarkers of bone turnover.

Intermittent exercise might be an efficient means of exercise for improving bone strength and quality. The aim of our study was to examine the effect of intermittent running on bone turnover markers using altered exercise-to-rest intervals. Twelve males completed one control (no exercise), and three, 45-min intermittent protocols (5, 20, and 80 s intervals) matched for distance and speed. Fasted venous blood samples were collected at baseline, 1, 2 and 24 h post-exercise. Carboxyterminal crosslinked telopeptide (CTX-I) and procollagen type 1 amino-terminal propeptide (P1NP) were used as markers of bone resorption and formation. After adjustment for baseline, CTX-I concentration at 1 h was higher (very likely to most likely small) for 5 s (30.2%; ±90% confidence limits: 10%), 20 s (2.9.0%; ±10%) and 80 s (32.0%; ±10%) compared to control. The very likely small effect remained for 5 s at 2 h (30.2%; ±15%). The effect for 20 and 80 s was possibly trivial and possibly small/possibly trivial (∼14.5%; ±âˆ¼15%). Differences in P1NP concentrations were likely to very likely trivial (∼7.4%; ±âˆ¼7.6%). Circulating CTX-I concentration is affected acutely by intermittent running with short-interval (5 s) intermittent loading resulting in a prolonged attenuation in circadian rhythm of CTX-I up to 2 h that was not demonstrated as clearly by longer intervals despite matched internal and external training load.

Modeling children's development in gross motor coordination reveals key modifiable determinants. An allometric approach.

Children change their body size, shape, and gross motor coordination (GMC) as they grow. Further, GMC is expected to link to changes in children's body size, physical activity (PA), and physical fitness (PF). The objective was to model GMC changes in children followed longitudinally and to investigate associations between these changes and PA and PF levels. A total of 245 children (122 girls) were observed at 6 years of age and followed annually until 9 years. A sequence of allometric models was fitted, that is, 1. body mass, stature, and PA; 2. addition of four PF tests; 3. addition of four more PF tests. In Model 1, changes in GMC are nonlinear, and body mass (-0.60 ± 0.07, P < .001) and stature (2.91 ± 0.35, P < .001) parameter estimates were significant suggesting children with a more linear body size/shape showed higher GMC performances. Girls tend to outperform boys across time, and PA was not associated with GMC changes. Model 2 fitted the data better, and the PF tests (handgrip, standing long jump, 50-yard dash, and shuttle run) were significantly linked to GMC change. In Model 3, adding the remaining PF tests did not change the order of any factors importance. The greatest GMC changes were achieved by children whose body size/shape has an ectomorphic dominance across the years. Considering that leaner and physically fitter children tended to be more coordinated, physical education should also focus on PF development in components related to muscular strength, speed, agility, and aerobic capacity, along with nutritional education to reduce fat mass.

Bone mineral density in vocational and professional ballet dancers.

According to existing literature, bone health in ballet dancers is controversial. We have verified that, compared to controls, young female and male vocational ballet dancers have lower bone mineral density (BMD) at both impact and non-impact sites, whereas female professional ballet dancers have lower BMD only at non-impact sites. INTRODUCTION: The aims of this study were to (a) assess bone mineral density (BMD) in vocational (VBD) and professional (PBD) ballet dancers and (b) investigate its association with body mass (BM), fat mass (FM), lean mass (LM), maturation and menarche. METHODS: The total of 152 VBD (13 ± 2.3 years; 112 girls, 40 boys) and 96 controls (14 ± 2.1 years; 56 girls, 40 boys) and 184 PBD (28 ± 8.5 years; 129 females, 55 males) and 160 controls (27 ± 9.5 years; 110 female, 50 males) were assessed at the lumbar spine (LS), femoral neck (FN), forearm and total body by dual-energy X-ray absorptiometry. Maturation and menarche were assessed via questionnaires. RESULTS: VBD revealed lower unadjusted BMD at all anatomical sites compared to controls (p < 0.001); following adjustments for Tanner stage and gynaecological age, female VBD showed similar BMD values at impact sites. However, no factors were found to explain the lower adjusted BMD values in VBD (female and male) at the forearm (non-impact site), nor for the lower adjusted BMD values in male VBD at the FN. Compared to controls, female PBD showed higher unadjusted and adjusted BMD for potential associated factors at the FN (impact site) (p < 0.001) and lower adjusted at the forearm (p < 0.001). Male PBD did not reveal lower BMD than controls at any site. CONCLUSIONS: Both females and males VBD have lower BMD at impact and non-impact sites compared to control, whereas this is only the case at non-impact site in female PBD. Maturation seems to explain the lower BMD at impact sites in female VBD.

Incidence of endotracheal tube colonization with the use of PneuX endotracheal tubes in patients following cardiac surgery.

INTRODUCTION: Ventilator-associated pneumonia (VAP) develops in up to 25% of patients following cardiac surgery. Colonization of the endotracheal tube (ETT) contributes to VAP. The PneuX ETT has been shown to halve VAP in high-risk patients undergoing cardiac surgery. This article reports on the secondary analysis of bacterial colonization in relation to VAP between the PneuX and standard ETTs. METHODS: In this randomized controlled trial, patients were randomized on a 1:1 basis to Group A (PneuX ET, N=120) or Group B (standard ETT, N=120). Patients aged >70 years with or without impaired left ventricular function (<50%) undergoing elective and urgent cardiac surgery were included in this study. Incidence of postoperative VAP and analysis of bacterial colonization within the ETT (N=234) were measured for patients requiring <24 h, 24-48 h and >48 h of intubation. RESULTS: Baseline patient demographics were comparable. VAP was lower in Group A compared with Group B (10.8% vs 21%; P=0.03). The incidence of VAP was lower at each time point for Group A. There was a lower incidence of ETT colonization in Group A for patients needing >48 h of intubation. There was no difference in the type of bacterial colonization (P=0.5) or the mean number of colony-forming units [4.35x107 (1.18x108) and 2.16x108 (1.24x109) in Groups A and B, respectively (P=0.8)]. CONCLUSION: Colonization of the ETT does not seem to play an important role in early-onset VAP. There is a tendency for reduced colonization in the PneuX ETT with longer intubation times. This may have an impact on reducing the incidence of late-onset VAP.

Scaling waist girth for differences in body size reveals a new improved index associated with cardiometabolic risk.

Our aim was to examine whether a new ratio, waist divided by height0.5 (WHT.5R), is both independent of stature and a stronger predictor of cardiometabolic risk (CMR) than other anthropometric indices. Subjects (4117 men and 646 women), aged 20-69 years, were assessed for stature (cm), mass (kg), waist, and hip girths (cm) from which body mass index (BMI), waist-to-hip ratio (WHR), waist-to-height ratio (WHTR), and two new indices, a body shape index (ABSI) and WHT.5R, were determined. We used the allometric power law, W = a.HTb , to obtain a simple body shape index for waist girth (W) to be independent of stature (HT). Physical activity was determined using self-report, and physical fitness was determined using the Bruce protocol. Glucose, total cholesterol, low-density lipoprotein, high-density lipoprotein, triglycerides, and TC/HDL ratio were determined from fasting venous blood samples. A single CMR composite score was derived from log-transformed z-scores of Triglycerides + average blood pressure ((diastolic + systolic)/2) + glucose + HDL (*-1). Results confirmed WHT.5R to be independent of stature and the strongest predictor of CMR, compared with BMI, WC, WHR, ABSI, and WHTR. We also found that CMR scores decline significantly with increasing fitness and physical activity, confirming that being fit and active can compensate for the adverse effects of being fat as measured by all other anthropometric indices. In conclusion, WHT.5R was the best anthropometric index associated with CMR, and being both physically fit and active has a protective effect on CMR, irrespective of weight status.

Longitudinal development of match-running performance in elite male youth soccer players.

This study longitudinally examined age-related changes in the match-running performance of retained and released elite youth soccer players aged 8-18 years. The effect of playing position on age-related changes was also considered. Across three seasons, 263 elite youth soccer players were assessed in 1-29 competitive matches (988 player-matches). For each player-match, total distance and distances covered at age group-specific speed zones (low-speed, high-speed, sprinting) were calculated using 1 Hz or 5 Hz GPS. Mixed modeling predicted that match-running performance developed nonlinearly, with age-related changes best described with quadratic age terms. Modeling predicted that playing position significantly modified age-related changes (P < 0.05) and retained players covered significantly more low-speed distance compared with released players (P < 0.05), by 75 ± 71 m/h (mean ± 95% CI; effect size ± 95% CI: 0.35 ± 0.34). Model intercepts randomly varied, indicating differences between players in match-running performance unexplained by age, playing position or status. These findings may assist experts in developing training programs specific to the match play demands of players of different ages and playing positions. Although retained players covered more low-speed distance than released players, further study of the actions comprising low-speed distance during match play is warranted to better understand factors differentiating retained and released players.

Physical employment standards for U.K. fire and rescue service personnel.

BACKGROUND: Evidence-based physical employment standards are vital for recruiting, training and maintaining the operational effectiveness of personnel in physically demanding occupations. AIMS: (i) Develop criterion tests for in-service physical assessment, which simulate the role-related physical demands of UK fire and rescue service (UK FRS) personnel. (ii) Develop practical physical selection tests for FRS applicants. (iii) Evaluate the validity of the selection tests to predict criterion test performance. METHODS: Stage 1: we conducted a physical demands analysis involving seven workshops and an expert panel to document the key physical tasks required of UK FRS personnel and to develop 'criterion' and 'selection' tests. Stage 2: we measured the performance of 137 trainee and 50 trained UK FRS personnel on selection, criterion and 'field' measures of aerobic power, strength and body size. Statistical models were developed to predict criterion test performance. Stage 3: matter experts derived minimum performance standards. RESULTS: We developed single person simulations of the key physical tasks required of UK FRS personnel as criterion and selection tests (rural fire, domestic fire, ladder lift, ladder extension, ladder climb, pump assembly, enclosed space search). Selection tests were marginally stronger predictors of criterion test performance (r = 0.88-0.94, 95% Limits of Agreement [LoA] 7.6-14.0%) than field test scores (r = 0.84-0.94, 95% LoA 8.0-19.8%) and offered greater face and content validity and more practical implementation. CONCLUSIONS: This study outlines the development of role-related, gender-free physical employment tests for the UK FRS, which conform to equal opportunities law.

The need to redefine age- and gender-specific overweight and obese body mass index cutoff points.

For convenience, health practitioners and clinicians are inclined to classify people/patients as overweight or obese based on body mass index (BMI) cutoff points of 25 and 30 kg m(-2) respectively, irrespective of age and gender. The purpose of the current study was to identity whether, for the same levels of adiposity, BMI is the same across different age groups and gender. A two-way ANCOVA revealed significant differences in BMI between different age groups and gender (plus an interaction), using body fat (%) as the covariate, data taken from a random sample of the English population (n=2993). Younger people had greater BMI than older people for the same levels of adiposity (differences ranged by 4 BMI units for males, and 3 BMI units for females). In conclusion, if BMI thresholds for overweight (BMI=25 kg m(-2)) and obese (BMI=30 kg m(-2)) are to reflect the same levels of adiposity across all gender and age groups within a population, then age- and gender-specific BMI adjustments outlined here are necessary to more accurately/fairly reflect the same critical levels of adiposity.

Provision of structured diabetes information encourages activation amongst people with diabetes as measured by diabetes care process attainment: the WICKED Project.

BACKGROUND: People with diabetes have better outcomes if they actively participate in their care. Patient-focused interventions can be effective in activating patients. Yet there is no known trial to evaluate the impact of the provision of individualized diabetes-specific information on patient activation and diabetes care outcomes. METHODS: In a randomized controlled trial, all people (n = 14 559) with diabetes within the local health economy were recruited and cluster randomized into two groups with the active group mailed a structured personalized report containing information on all nine of their diabetes care processes, whereas the control group received standard care. Differences in their Failed Process Score (FPS) were compared at three months. RESULTS: At three months, the FPS score (1.25 ± 1.87 vs. 1.35 ± 1.97, P < 0.01) and the change in FPS score (0.48 ± 1.55 vs. 0.42 ± 1.49, P < 0.02) were significantly better in those mailed a structured personalized report. A dichotomized FPS score [good attainment (GA) vs. poorer attainment], was significantly better in those mailed (χ2 = 10.0, P < 0.05) and using a binary logistic regression analysis adjusting for all demographic factors and the baseline FPS, the relative effect of mailing compared with non-mailing on three-month GA category was OR 1.14 (95% CI 1.04-1.25, P < 0.01). CONCLUSIONS: Provision of structured and individualized information to people with diabetes can positively influence the level of patient activation, promote better engagement and open the potential to improve other crucial diabetes outcomes.

Identifying the ideal body size and shape characteristics associated with children's physical performance tests in Peru.

We used allometric models to identify the optimal body size/shape characteristics associated with physical and motor performance tests in Peruvian schoolchildren. The sample consisted of 3624 subjects (1669 boys and 1955 girls) aged 11-17 years from 31 public schools belonging to four cities located in the three natural regions in central Peru. Motor performance included 12-min run, standing long jump, grip strength, curl-ups, shuttle run, and sit and reach. The reciprocal Ponderal index (RPI), a characteristic sometimes referred to as the somatotype "ectomorphy," was found to be the most suitable body shape indicator associated with 12-min run, standing long jump, curl-up, and shuttle run performance. A positive maturation offset parameter was also associated with greater standing long jump, grip strength, shuttle run, and sit-and-reach performances. With the exception of the sit-and-reach flexibility, sex differences are pervasive in all tests favoring boys. Rainforest schoolchildren are best performers in the power and flexibility tests, whereas those from high altitude were superior in the 12-min endurance test even after taking their much lighter body size characteristics into account. This latter finding suggests that living at high altitude in Peru benefits children's endurance performance both before and even after controlling for differences in the confounding variable of body size/shape.

Effect of fat free mass on serum and plasma BDNF concentrations during exercise and recovery in healthy young men.

Exercise results in release of brain derived neurotrophic factor into the circulation; however, little is known about the changes in serum and plasma brain derived neurotrophic factor concentrations and factors influencing brain derived neurotrophic factor during exercise and recovery. Serum (n=23) and plasma (n=10) brain derived neurotrophic factor concentrations were measured in healthy young men at rest, during steady-rate and after exercise to determine the maximum aerobic power. A two-way analysis of variance was used to investigate brain derived neurotrophic factor levels in blood during exercise and recovery, with one between-subject factor (a median split on: age, height, body mass, fat free mass, body mass index and aerobic fitness), and one within-subject factor (time). Serum brain derived neurotrophic factor concentrations increased in response to exercise and declined rapidly in recovery. Plasma brain derived neurotrophic factor had a greater proportional increase relative to exhaustive exercise compared with serum brain derived neurotrophic factor and was slower to return to near baseline values. There was a significant group-by-time interaction indicating a greater release and faster recovery for serum brain derived neurotrophic factor in high- compared with low-fat free mass individuals.

A 4-week instructed minimalist running transition and gait-retraining changes plantar pressure and force.

The purpose of this study is to compare changes in plantar pressure and force using conventional running shoes (CRS) and minimalist footwear (MFW) pre and post a 4-week MFW familiarization period. Ten female runners (age: 21 ± 2 years; stature: 165.8 ± 4.5 cm; mass: 55.9 ± 3.2 kg) completed two 11 km/h treadmill runs, 24 hours apart, in both CRS and MFW (pretest). Plantar data were measured using sensory insoles for foot strike patterns, stride frequency, mean maximum force ( M ⁢ F ¯ ), mean maximum pressure ( M ⁢ P ¯ ) and eight mean maximum regional pressures. Subjects then completed a 4-week familiarization period consisting of running in MFW and simple gait-retraining, before repeating the tests (posttest). During the pretests, 30% of subjects adopted a forefoot strike in MFW, following familiarization this increased to 80%; no change occurred in CRS. A significant decrease in M ⁢ F ¯ in both MFW and CRS (P = 0.024) was observed from pre-post, and a significant decrease in heel pressures in MFW. M ⁢ P ¯ was higher in MFW throughout testing (P < 0.001).A 4-week familiarization to MFW resulted in a significant reduction in M ⁢ F ¯ in both the CRS and MFW conditions, as well as a reduction in heel pressures. Higher M ⁢ P ¯ was observed throughout testing in the MFW condition.

A field-test battery for elite, young soccer players.

The validity and reliability of a battery of field-based performance tests was examined. The opinions of coaches, fitness professionals and players (n=170, 172 and 101 respectively) on the importance of performance testing were established using a questionnaire. On 2 occasions, separated by 7 days, 80 elite, young soccer players (mean±SD [and range]: age 13.2±2.6 [8.9-19.1] years; stature 1.59±0.18 m [1.32-1.91]; body mass 50.6±17.1 [26.5-88.7] kg) completed a battery of field-based tests comprised of heart rate response to a submaximal Multi-stage fitness test, 3 types of vertical jump, sprints over 10 and 20 m, and an agility test. Physical performance testing was considered important by coaches (97%), fitness professionals (94%) and players (83%). The systematic bias ratio and the random error components of the 95% ratio limits of agreement for the first and second tests, for the U9-U11 vs. U12-U14 vs. U15-U18 age groups, were [Systematic bias (*/÷ ratio limits)]: Heart rate (Level 5): 0.983 (*/÷ 1.044) vs. 0.969 (*/÷ 1.056) vs. 0.983 (*/÷ 1.055); Rocket jump: 0998 (*/÷ 1.112) vs. 0.999 (*/÷ 1.106) vs. 0.996 (*/÷ 1.093); 10 m sprint: 0.997 (*/÷ 1.038) vs. 0.994 (*/÷ 1.033) vs. 0.994 (*/÷ 1.038); Agility test: 1.010 (*/÷1.050) vs. 1.014 (*/÷1.050) vs. 1.002 (*/÷1.053). All tests, except heart rate recovery from the Multi-stage fitness test, were able to distinguish between different ability and age groups of players (p<0.05). Thus, the field-test battery demonstrated logical and construct validity, and was shown to be a reliable and objective tool for assessing elite, young soccer players.

Colorectal cancer incidence and trend in UK South Asians: a 20-year study.

AIMS: South Asians comprise 13.6% of the Wolverhampton population. We aimed to compare the incidence and trend of colorectal cancer in this subgroup with the non South Asian population over a 20-year period. METHOD: Patients of South Asian origin diagnosed with colorectal cancer from 1989 to 2008 were identified from the hospital histopathology database and compared with those of non South Asian origin. 1991 and 2001 census data were used to standardize for differing age and sex distributions in the two study populations. RESULTS: The median unadjusted incidence of colorectal cancer from 1989 to 2008 was 6.17 per 100,000 per year in South Asians compared with 71.70 per 100,000 per year in non South Asians (77.79% white British). The age and sex adjusted odds ratio for colorectal cancer in South Asians was 0.2 (P < 0.001). There was an equal increased trend in the incidence in both the South Asians and non South Asians over the study period (0.8% per year). In patients < 50 years, the gender difference in the incidence of cancer was not significant, but as age increased this rose significantly (males > females). CONCLUSION: There was a markedly lower incidence of colorectal cancer in South Asians compared with non South Asians, maintained over 20 years. Colorectal cancer incidence increased by a small and similar amount over the period in both groups. There was a male preponderance of colorectal cancer in both populations over 50 years.

Predictors of rehabilitation intention and behavior following anterior cruciate ligament surgery: an application of the Theory of Planned Behavior.

This study was guided by the Theory of Planned Behavior (TPB) to assess the predictors of rehabilitation intention and adherence following anterior cruciate ligament (ACL) reconstructive surgery in athletes. Participants (n=87; mean age=28.95±7.7 years) volunteered to participate following their first post-surgery physiotherapy session and completed the baseline measures of intention, attitudes, subjective norm, perceived behavioral control, self-efficacy, participation level, sport and age. At follow-up, 48 participants returned completed rehabilitation diaries detailing adherence behavior every 2 weeks during an 8-week period. Results indicated that there was no significant difference in rehabilitation behavior at weeks 2, 4, 6 or 8. A multivariate analysis of covariance indicated that sport type, sport level, intention and intention(2) significantly predicted rehabilitation behavior, although the strength of relationship varied across the weeks. Self-efficacy was a significant predictor of intention. These findings suggest that adherence behavior is predicted by sport type, participation level and curvilinearly by intention to adhere. Intention to adhere can be positively associated with enhanced self-efficacy. The study has highlighted issues that practitioners should be aware of when encouraging rehabilitation adherence. However, the TPB provided a poor fit for understanding adherence behavior in this setting.

Physical activity, walking and leanness: an analysis of the Northern Ireland Sport and Physical Activity Survey (SAPAS).

OBJECTIVE: To report on the contribution walking makes to total weekly physical activity and the relationship between the volume and intensity of walking and leanness in a representative sample of the Northern Ireland population. METHOD: 4563 adults participated in this cross-sectional survey of physical activity behaviour. Self-reported height and weight was used to determine inverse body mass index (iBMI) as a measure of leanness. Data across all domains of physical activity including self-reported volume and intensity of walking (in bouts of 10 min or more) were analysed to determine their contribution to leanness using ANCOVA, having controlled for age, gender, socio-economic and smoking status. RESULTS: Over 68% of the participants reported walking >10 minutes during the previous week but only 24% report walking at a brisk or fast pace. Time walking at a brisk or fast pace for personal transport was identified as having the strongest positive association with being lean (F(1,4256)=10.45, ß=0.051 cm(2) kg(-1) min(-1) (SE=0.016),P=0.001). CONCLUSIONS: In addition to increasing the amount of walking and the percentage of people walking regularly, public health messages encouraging an increase in walking pace may be valuable to increase the proportion of the population meeting physical activity guidelines and gaining associated health benefits.