Lessons From Special Forces Operators for Elite Team Sports Training: How to Make the Whole Greater Than the Sum of the Parts.

This methodology paper describes the design of a holistic and multidisciplinary human performance program within the Belgian Special Forces Group, the Tier 1 Special Operations unit of the Belgian Defense. Performance management approaches in the military draw heavily on sports science. The key component of the program design described here is its integrative nature, which team sports training might benefit from. The basic rationale behind the program was to bridge several gaps: the gap between physical and mental training; the gap between the curative or preventive medical approach and the performance enhancement approach; and the gap between individual and team training. To achieve this goal, the methodology of Intervention Mapping was applied, and a multidisciplinary team of training and care professionals was constituted with operational stakeholders. This was the first step in the program design. The second step took a year, and consisted of formal and informal consultations, participant observations and task analyses. These two first stages and their conclusions are described in the Method section. The Results section covers the next two stages (three and four) of the process, which aimed at defining the content of the program; and to test a pilot project implementation. The third stage encompassed the choice of the most relevant assessment and intervention tools for the target population, within each area of expertise. This is described extensively, to allow for replication. The fourth and last stage was to "test drive" the real-life integration and implementation of the whole program at the scale of a single team (8 individuals). For obvious confidentiality reasons, the content data will not be reported extensively here. Implications for wider-scale implementation and tie-back to sports team training are presented.

A surface electromyography based objective method to identify patients with nonspecific chronic low back pain, presenting a flexion related movement control impairment.

Movement control impairments (MCI) are often present in patients with non-specific chronic low back pain (NS-CLBP). Therefore, movement control exercises are widely used to rehabilitate patients. However, the objective assessment remains difficult. The purpose of this study was to develop a statistical model, based on logistic regression analysis, to differentiate patients with NS-CLBP presenting a flexion-related MCI from healthy subjects. This model is based on trunk muscle activation patterns measured by surface electromyography (sEMG), during movement control exercises. Sixty-three healthy male subjects and 36 male patients with a flexion-related MCI participated in this study. Muscle activity of the internal obliques, the external obliques, the lumbar multifidus and the thoracic part of the iliocostalis was registered. Ratios of deep stabilizing to superficial torque producing muscle activity were calculated to examine trunk muscle recruitment patterns during 6 different exercises. Logistic regression analyses were performed (1) to define the ratios and exercises that were most discriminating between patients and non-patients, (2) to make a predictive model. K-Fold cross-validation was used to assess the performance of the predictive model. This study demonstrated that sEMG trunk muscle recruitment patterns during movement control tests, allows differentiating NSCLBP patients with a flexion-related MCI from healthy subjects.

Velocity of isokinetic trunk exercises influences back muscle recruitment patterns in healthy subjects.

Isokinetic exercises at different angular velocities on Cybex devices are often used for assessment and therapy in chronic low back pain patients. Little is known about the effect of velocity of movement on the muscle activity during these exercises. The purpose of this study was to investigate both relative muscle activity and ratios of local to global muscle activity at the different velocities of isokinetic movements on a Cybex dynamometer. Fifty-three healthy employees of Belgian Defence (26 male and 27 female) aged between 20 and 57 years old voluntarily performed isometric and isokinetic exercises at four different velocities. Surface electromyographic signals of different abdominal and back muscles were recorded on both sides. Both the relative muscle activity and the local to global muscle activity ratio of the back muscles were affected by changes in velocities of isokinetic exercises. The global muscle system was more influenced by changes in velocity, than the local muscle system. Abdominal relative muscle activity and ratios were not influenced by velocity of movement. This study revealed that the velocity of isokinetic extension exercises influences the recruitment of the back muscles, meaning that protocols of training programs should be adapted in function of the focus of the therapy.

Delayed vastus medialis obliquus to vastus lateralis onset timing contributes to the development of patellofemoral pain in previously healthy men: a prospective study.

BACKGROUND: Delayed onset of vastus medialis obliquus activity has been described in patellofemoral pain patients. No prospective study investigating the development of patellofemoral pain has tested the onset timing of electromyographic activity of the vastus medialis obliquus and vastus lateralis muscles during a functional task. HYPOTHESIS: Before the development of patellofemoral pain, subjects demonstrate an altered firing order of the vastus medialis obliquus and vastus lateralis muscles compared with healthy subjects during a functional task. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: The onset of vastus medialis obliquus and vastus lateralis activity was measured with surface electromyography during a functional task (rocking back on the heels) in 79 healthy subjects subsequently submitted to a 6-week strenuous basic military training. Afterward, these subjects were reassessed. RESULTS: Thirty-two percent of the recruits developed patellofemoral pain during training. Patellofemoral pain subjects demonstrated a significant delay of onset of vastus medialis obliquus electromyographic activity compared with the healthy controls (P = .023), even before basic military training. In healthy subjects, no significant differences in electromyographic activity onset of the vastus medialis obliquus compared with the vastus lateralis could be identified before and after basic military training. A significant (P < .001) delay could be demonstrated in the patellofemoral pain group after basic military training. A binary logistic regression could be constructed wherein the onset of the electromyographic activity of the vastus medialis obliquus and vastus lateralis was withheld in the model. The most optimal cutoff value, which is based on the receiver operating characteristic curve, is a timing difference of -0.67 milliseconds (vastus medialis obliquus - vastus lateralis). The area under the receiver operating characteristic curve is considered as fair (0.68). CONCLUSION: Delayed onset of electromyographic activity of the vastus medialis obliquus-vastus lateralis is one of the contributing risk factors to the development of patellofemoral pain.

Specific associations between types of physical activity and components of mental health.

Findings of previous studies suggest that the relationship between physical activity and mental health may change across different domains of physical activity, different dimensions of mental health, and different population subgroups. The present study examined associations between five types of physical activity with different contents: housework, leisure active transportation, biking to/from work, walking to/from work, and sports participation, and two dimensions of mental health: perceived stress and psychological distress, in 1919 participants aged 20-65 years, using the data from the Flemish Policy Research Centre Sport, Physical Activity and Health. Multiple logistic regression analyses were performed with the total sample, and with the sample stratified by gender, age, and occupational category. Further, separate models were used in the gender and age subgroups of each occupational category. Sports participation was the only type of physical activity inversely associated with both stress (OR=0.375; CI: 0.200-0.704) and distress (OR=0.480; CI: 0.253-0.910). Sports participation related to less distress in unemployed mid-aged adults, and to less stress in unemployed women, unemployed young adults, and young adults with blue-collar jobs. Housework was associated with more stress and more distress in women with blue-collar jobs. In young adults with white-collar jobs, however, an inverse association between housework and distress was found. Biking to and from work was associated with more stress in men with blue-collar jobs. Results invite consideration for the utility, and perhaps the necessity, of differentiated health recommendations for physical health and for mental health in different population subgroups.

Lipid profile in men and women with different levels of sports participation and physical activity.

OBJECTIVE: The purpose of the present study was to analyse the lipid profile in men and women differentiated according to energy expenditure during sports participation (EE(SPORT)), energy expenditure during active leisure time (EE(ALT)) and overall energy expenditure (EE(TOTAL)). DESIGN: The subjects were grouped by sex, age, EE(SPORT), EE(ALT) and EE(TOTAL). Group differences were analysed using analyses of covariance with BMI and alcohol consumption as covariates. SETTING: Physical activity was assessed using the Flemish Physical Activity Computerised Questionnaire. Fasting blood samples were taken to measure total cholesterol (TC), TAG, HDL-cholesterol (HDL-C), LDL-cholesterol (LDL-C) and the ratio TC:HDL-C. SUBJECTS: The study sample consisted of 1170 Flemish men and women between 18 and 75 years of age. RESULTS: Differences in lipid profile were observed in the younger age group (<45 years), all in favour of the most active group. More specifically, when differentiating by EE(ALT) and EE(TOTAL), men had a healthier lipid profile for TAG, HDL-C and TC:HDL-C. Differentiation according to EE(SPORT) revealed the same significant results except for TAG. In women significant results for HDL-C, LDL-C and TC:HDL-C were found when differentiated by EE(SPORT). CONCLUSIONS: Men and women <45 years of age with higher levels of energy expenditure due to sport show a better lipid profile than their sedentary counterparts. When differentiating subjects according to energy expenditure during active leisure time or overall energy expenditure, only in men was a healthier lipid profile observed in favour of the most active subjects.

Reliability and validity of the Flemish Physical Activity Computerized Questionnaire in adults.

The purpose of this study was to investigate the test-retest reliability and concurrent validity of the Flemish Physical Activity Computerized Questionnaire (FPACQ) in employed/unemployed and retired people. The FPACQ was developed to assess detailed information on several dimensions of physical activity and sedentary behavior over a usual week. A triaxial accelerometer, the RT3 Triaxial Research Tracker (RT3), in combination with a written 7-day activity record, was used as the objective criterion measure. In employed/unemployed people, 2-week test-retest reliability for several activity variables calculated from the FPACQ was good to excellent with intraclass correlations (ICCs) ranging from .67 to .99. In retired people ICCs were lower but, except for time spent eating, still fair to excellent, ranging from .57 to .96. Except for time spent in leisure time activities for men and the average energy expenditure related to sports participation in women, correlations between the RT3 and the FPACQ generally supported the relative validity of the FPACQ for employed/unemployed people (r ranging from .37 to .88). Values for retired people were somewhat lower (r ranging from .15 to .85), but most variables still reached at least moderate correlations. Concerning absolute validity, the FPACQ generally overestimated physical activity and underestimated sedentary behavior compared to the RT3. From this study, it can be concluded that the FPACQ is a reliable and reasonably valid questionnaire for assessing different dimensions of physical activity and sedentary behavior.

Dietary factors associated with obesity indicators and level of sports participation in Flemish adults: a cross-sectional study.

BACKGROUND: Obesity develops when energy intake continuously exceeds energy expenditure, causing a fundamental chronic energy imbalance. Societal and behavioural changes over the last decades are held responsible for the considerable increase in sedentary lifestyles and inappropriate dietary patterns. The role of dietary fat and other dietary factors in the aetiology and maintenance of excess weight is controversial. The purposes of the present study were to investigate the dietary factors associated with body mass index (BMI) and waist circumference (WC), and to analyse whether dietary intake varies between subjects with different levels of sports participation. METHODS: Data for this cross-sectional study, including anthropometric measurements, 3-day diet diary and physical activity questionnaire, were collected by the Flemish Policy Research Centre Sport, Physical Activity and Health (SPAH) between October 2002 and April 2004. Results of 485 adult men and 362 women with plausible dietary records were analysed. Analyses of covariance were performed to determine the differences in dietary intake between normal weight, overweight and obese subjects, and between subjects with different levels of sports participation. RESULTS: Total energy intake, protein and fat intake (kcal/day) were significantly higher in obese subjects compared to their lean counterparts in both genders. Percentage of energy intake from fat was significantly higher in obese men compared to men with normal weight or WC. Energy percentages from carbohydrates and fibres were negatively related to BMI and WC in men, whereas in women a higher carbohydrate and fibre intake was positively associated with obesity. Alcohol intake was positively associated with WC in men. Subjects participating in health related sports reported higher intake of carbohydrates, but lower intake of fat compared to subjects not participating in sports. CONCLUSION: This study supports the evidence that carbohydrate, fat, protein and fibre intake are closely related to BMI and WC. The sex differences for dietary intake between obese men and women might reflect the generally higher health consciousness of women. Alcohol intake was only associated with WC, emphasizing the importance of WC as an additional indicator in epidemiological studies. Besides enhancing sports and physical activity, it is necessary to improve the knowledge about nutrition and to promote the well-balanced consumption of wholesome food.

Methodological issues associated with longitudinal research: findings from the Leuven Longitudinal Study on Lifestyle, Fitness and Health (1969 - 2004).

Longitudinal studies provide unique opportunities but are also faced with several limitations. The purpose of this study was to document three of these issues ("imperfect" design, evolution of data collection methods, representativeness) by means of the Leuven Longitudinal Study on Lifestyle, Fitness and Health (LLSLFH). The LLSLFH (1969 - 2004) comprises observations on males between 12 and 18 years and at 30, 35, 40, and 47 years, and on females at 16 and 40 years. In the most recent phase of the study, spouses and offspring were also included. The different phases and evolving research questions throughout the LLSLFH required an appropriate adaptation of the research design. The associated evolution of data collection methods largely reflects the changing ideas about physical fitness, body composition, and physical activity, the continuing search for new and better measurement techniques, and the need for adaptations with age. Ongoing study participants are representative in terms of body composition and, except for adolescence in males, also physical activity. No straightforward answer can be given concerning physical fitness. In both sexes, socio-economic status is above average. When informed about the possible "pitfalls" of longitudinal research in advance, several measures could be taken to prevent or limit them as much as possible.

Secular trends in anthropometric characteristics, physical fitness, physical activity, and biological maturation in Flemish adolescents between 1969 and 2005.

In this study, secular trends in anthropometric characteristics, physical fitness, physical activity, and biological maturity over the past 25-35 years in Flemish adolescents were investigated. Representative cross-sectional samples of 12-18-year-old secondary school children (11,899 assessments in boys in 1969-1974, 4,899 girls in 1979-1980, 1,429 boys and 1,772 girls in 2005) and parent-offspring pairs tested at approximately the same age during adolescence (55 father-son pairs, mean age fathers = 15.47 years, mean age sons = 15.38 years; 62 mother-daughter pairs, mean age mothers = 16.63 years, mean age daughters = 15.01 years) were used. The cross-sectional data were analyzed in 6 yearly age-categories using Wilcoxon rank sum tests. For the parent-offspring data paired t-tests, simple linear regressions to adjust for parent-offspring differences in chronological age and multiple linear regressions to adjust for parent-offspring differences in chronological and skeletal age were conducted. The cross-sectional study generally revealed an increase in weight, stature, BMI, skinfolds and trunk-extremity index, and a decrease in the performance on several physical fitness tests. In the parent-offspring study, only sons were maturationally advanced compared to fathers. Even after adjustment for parent-offspring differences in chronological age and in chronological and skeletal age, results for stature, trunk-extremity index and physical fitness were generally similar to the cross-sectional study. No secular trend was observed for sports participation. The fact that the positive secular trends in weight, BMI, and skinfolds of the cross-sectional study were not entirely confirmed in the parent-offspring study is probably due to higher similarity in genetic and familial background, higher socio-economic status, and more health-consciousness of the latter.

Muscular strength, aerobic fitness, and metabolic syndrome risk in Flemish adults.

PURPOSE: To investigate the association of muscular strength and aerobic fitness with a continuous metabolic syndrome risk score in male and female adults. METHODS: This cross-sectional study included 1019 (571 men) Flemish adults, aged 18-75. Muscular strength was evaluated by measuring isometric knee extension and flexion peak torque, using a Biodex System Pro 3 dynamometer. Aerobic fitness was quantified as VO2peak and was determined during a maximal cycle ergometer exercise test. Both strength and aerobic fitness were scaled for differences in FFM, using allometric analyses. A validated metabolic syndrome risk score that was based on waist circumference, triglycerides, blood pressure, fasting plasma glucose, and HDL cholesterol was used. Metabolic syndrome risk score, strength, and aerobic fitness were analyzed as continuous variables using multiple linear regression. RESULTS: Metabolic syndrome risk was inversely associated with strength, independently of aerobic fitness, and after adjustment for age, height, education level, smoking status, and dietary intake in women (beta = -0.172, P < 0.001). In men, however, adjustment for aerobic fitness attenuated the inverse association between strength and metabolic syndrome risk (beta = -0.044, P > 0.05). Independently of strength, aerobic fitness was inversely associated with metabolic syndrome risk (men: beta = -0.309, P < 0.001; women: beta = -0.208, P < 0.001). Furthermore, independent associations were found for strength and aerobic fitness with several individual metabolic syndrome risk factors in women, and most of these associations were only partially mediated by central and general adiposity indicators. CONCLUSION: Although cross-sectional, the present results support inclusion of strength training in addition to aerobic exercise in physical activity recommendations for women, because both types of activity might show additional effects in reducing the risk of the metabolic syndrome.

Socio-economic and lifestyle factors associated with overweight in Flemish adult men and women.

BACKGROUND: Changes in lifestyles and in the environment over the last decades are probably the most important cause of the overweight epidemic, but the findings are inconsistent among studies. The purpose of this study was to investigate the association of several socio-economic and lifestyle factors with overweight in Flemish adults, using BMI > or = 25 kg/m2, waist circumference (WC) > or = 94 cm (men) or > or = 80 cm (women) and the combination of BMI and WC for identifying overweight. METHODS: This cross-sectional epidemiological study was conducted by the Flemish Policy Research Centre Sport, Physical Activity and Health between October 2002 and February 2004 in 46 Flemish communities. A total of 4903 Flemish adults (2595 men and 2308 women), aged 18 to 75 years, from a population-based random sample were included in the analysis. Body weight, height and WC were measured, and socio-economic and lifestyle factors were reported by means of validated questionnaires. RESULTS: The results of the logistic regressions revealed that age is positively associated with overweight in both genders. Alcohol consumption is associated with overweight only in men. Men smoking in the past and watching TV >11 h/week have significantly higher OR's for overweight, while men who participate in health related sports >4 h/week have significantly lower OR's for overweight. In women, watching TV >9 h/week was positively associated with overweight. Women who are current smokers or participate in health related sports >2.5 h/week or with a higher educational level have significantly lower odds for overweight. Different results are observed between the first (BMI) and the second model (WC) in both genders. In men, the models differ for education and health related sports, while in women they differ for smoking status and leisure time physical activity. CONCLUSION: The present study confirms the contention that overweight is a multifactorial problem. Age and TV viewing are positively associated with overweight, while educational level and health related sports are negatively related to overweight in both genders. In men, alcohol consumption and smoking in the past are also among the lifestyle factors associated with overweight. This study also indicates that BMI and WC do not have the same discriminative function regarding different lifestyle factors.

Tracking of physical fitness and physical activity from youth to adulthood in females.

PURPOSE: To evaluate stability of physical fitness and physical activity from adolescence into middle adulthood in Flemish females. METHODS: Within the scope of the Leuven Longitudinal Study on Lifestyle, Fitness and Health, 138 females (mean age=16.6+/-1.1 yr) from the Leuven Growth Study of Flemish Girls were seen in adulthood (mean age=40.5+/-1.1 yr). Several body dimensions and motor fitness tests were taken. Physical activity was assessed by means of a sports participation inventory. Inter-age correlations were calculated between adolescent and adult values. Cross-tabulation was used to identify the percentage of subjects remaining in the same BMI and physical activity group or shifting from one group to another from adolescence to adulthood. Odds ratios for less activity and overweight in adulthood according to adolescent activity or weight status were calculated. RESULTS: Except for flamingo balance, plate tapping, leg lifts, and arm pull, all anthropometric and physical fitness characteristics were stable from adolescence to adulthood (r ranging from 0.49 to 0.96). Sports participation was not a stable characteristic (r=0.13). From adolescence to adulthood, 84.5 and 63.6%, respectively, remained in the normal-weight and overweight group, whereas 62.5 and 54.4%, respectively, remained in the less active and active group. The odds of being overweight in adulthood was 9.53 (95% CI: 3.1-29.8) times greater in overweight compared with normal-weight adolescent girls. CONCLUSION: In Flemish females, anthropometric and fitness characteristics demonstrate higher levels of stability from adolescence to middle adulthood than physical activity. Weight status during adolescence is indicative of adult weight status, and a pattern of less activity rather than activity tends to continue from youth to adulthood.