Overweight and obesity among youth participants in American football

Determinants of LV mass in athletes: the impact of sport, constitutional traits and cardiovascular risk factors

BACKGROUND

Whether cardiovascular (CV) risk factors might impact Left Ventricular (LV) mass in athletes is unknown.

METHODS

The impact of CV risk factors (Total/LDL cholesterol, triglycerides, positive family history, smoking, body fat, blood pressure), constitutional characteristics (age, sex, body mass index) and type of sport was assessed in 1111 Olympic athletes.

RESULTS

Multivariate logistic regression analysis demonstrated a significant impact: BMI ≥ 30 kg/m² (odds ratio [OR] = 2.8. 95° Confidence Interval [CI] 0.9-13.7; < 0.001; in males); age ≥ 20-year (OR = 2.1, CI 1.4-3.3; p < 0.001) in males; (OR = 2.3; CI 1.4-3.7) in females; systolic blood pressure ≥ 130 mmHg (OR = 1.1, CI 1.01-1.16; p < 0.001) in males; (OR = 1.03; CI 1.01-1.06; p < 0.03) in females; diastolic ≥ 85 mmHg (OR = 1.1, CI 1.03-1.2; p = 0.003) in males; (OR = 1.05, CI 1.02-1.08, p < 0.001) in females. No association was found for family history, smoking, body fat, LDL, total cholesterol, triglycerides. Overall, constitutional traits explain > 60% of the LV mass. Sport explains on average 14%, but large differences existed among disciplines, i.e., endurance showed the highest impact (55%, mixed: 20%, power: 17%, skill: 8%; p < 0.001).

CONCLUSION

LV mass in athletes is largely governed by constitutional traits and type of sport, and independent from CV risk factors, except for systolic and diastolic blood pressure. Overall, constitutional traits explain more than 60% of LV mass. The impact of sport is largely different in relation to the discipline, and highest in endurance, moderate mixed and power and mild in skill disciplines.

Improper Fit in American Youth Football Helmets Across One Competitive Season

Improper helmet fit is related to sport-related concussion symptomology. The objective of this study was to determine the prevalence of improperly fit helmets in American youth tackle football players across one competitive season. Four recreation leagues including 147 players (45.2 ± 14.7 cm, 147.5 ± 9.0 kg), aged 7-12 years, participated in pre-season and post-season data collection timepoints. Participant and league demographics were collected at pre-season. Helmet fit was assessed at pre- and post-season using a 13-item checklist. A helmet was defined as improperly fit if failed to comply with or more of the checklist items. Most players (84%) rented helmets from the league. At preseason, 71.4% of helmets, and at post-season 79.6%, were improperly fit with no significant change over time (p = 0.14). Of the 105 improperly fit helmets at the start of the season, 61% were still considered improperly fit at post season. The 11-12 year old age group had significantly more improperly fit helmets than the 7-10 year old age group at post-season (p = 0.033), but not pre-season (p = 0.655). American youth football players depend on the league to fit their helmet. Most players did not meet at least one checklist criteria. Helmets improperly fit at preseason were still not fit at post.

A Comparison of an Alternative Weight-Grading Model Against Chronological Age Group Model for the Grouping of Schoolboy Male Rugby Players

Objectives

Concerns regarding marked differences in the weights and body composition of young rugby players competing within the same age groups have led to the suggestion of alternative models for grouping young players. The aims of this study were (1) to compare variance in the body size and body composition of schoolboy rugby players (9 to 14 years), across weight- and age-grading models, and (2) to identify morphotypes for the weight model using Hattori’s body composition chart.

Materials and Methods

Skinfold thickness measurements were used to assess body fat mass (BF), fat-free mass (FFM), body fat mass index (BFMI), and fat-free mass index (FFMI). Standardized measure of height and weight were taken for all participants. Data were grouped according to the age categories of the French Rugby Federation (U11: Under 11 years, U13: Under 13 years, and U15: Under 15 years), and to the weight categories (W30–44.9; W45–59.9; and W60–79.9) carried out from 25th and 75th weight percentile in each age category. Body mass index status (NW normal-weight versus OW/OB overweight/obese) was considered. Extreme morphotypes are characterized from BFMI and FFMI in the weight-grading model on Hattori’s body composition chart.

Results

The dispersion of anthropometric characteristics decreased significantly for the weight model, except for height in all groups and BFMI for U13. Among NW, 3, 1.8, and 0% upgraded; 18.2, 68.7, and 45.5% downgraded; among OW, 50, 21.5, and 12.5%; and among OB, 91.3, 83.3, and 74.6% upgraded, respectively, in U11, U13, U15. FFMI/BFMI were correlated in U11 (r = 0.80, p < 0.001), U13 (r = 0.66, p < 0.001), and U15 (r = 0.77, p < 0.001). There was no significant correlation in W45–59.9 and low correlations in W30–44.9 (r = 0.25, p < 0.001) and W60–79.9 (r = 0.29, p < 0.001). Significant grading difference between the centroids (p < 0.05) and the distribution deviates from centroids of BFMI and FFMI (p < 0.0001) were noted between the two models. Thirteen players were located in adipo-slender, twenty-three in adipo-solid, twenty-two in lean-slender, and two located in the lean-solid morphotype in weight model.

Conclusion

A weight-grading model should be considered to limit mismatches in anthropometric variables. However, variations of body composition also persisted for this model. Hattori’s body composition chart allowed more detailed examination of morphological atypicalities among schoolboy rugby players.

Exertional heat illness risk factors and physiological responses of youth football players

OBJECTIVE

To determine which intrinsic and extrinsic exertional heat illness (EHI) risk factors exist in youth American football players and observe perceptual and physiological responses of players during events (games and practices).

METHODS

Cross-sectional cohort study observing 63 youth football players, varying in position. Independent variables were league (weight-restricted (WR, n = 27) and age-restricted (AR, n = 36)) and event type. Dependent variables were anthropometrics, work-to-rest ratio, and wet bulb globe temperature. Descriptive variables included preparticipation examination and uniform configuration. A subset of 16 players participated in physiological variables (heart rate and gastrointestinal temperature). Data collection occurred on 7 AR and 8 WR nonconsecutive practices and the first 3 games of the season.

RESULTS

Mean values for anthropometric variables were higher (p < 0.05) in the AR league than the WR league. Work time (χ² (1,111) = 4.232; p = 0.039) and rest time (χ² (1,111) = 43.41; p < 0.001) were significantly greater for games, but ratios were significantly higher for practices (χ² (1,111) = 40.62; p < 0.001). The majority of events (77%) observed were in black and red flag wet bulb globe temperature risk categories. A total of 57% of the players had a preparticipation examination, and up to 82% of events observed were in full uniforms. Individual gastrointestinal temperature and heart rate responses ranged widely and no players reached critical thresholds.

CONCLUSION

Extrinsic (disproportionate work ratios, environmental conditions) and intrinsic (higher body mass index) EHI risk factors exist in youth football. Certain risk factors may be influenced by event and league type. National youth football organizations need to create thorough guidelines that address EHI risk factors for local leagues to adopt.

Epidemiology of American Football Injuries at Universities in the United Kingdom

Background:

College-level American football injury data are routinely collected; however, data relating to American football injuries at universities in the United Kingdom have never been reported.

Purpose:

To describe the epidemiology of UK university American football injuries.

Study Design:

Descriptive epidemiology study.

Methods:

An online survey tool was used to collect the injury data of 410 players from 56 UK university teams who participated in the 2014-2015 British Universities and College Sports American football season. Survey data were collected from January to February 2016 and were analyzed to determine the incidence and patterns of injury.

Results:

Overall, 710 injuries and 204 concussions were self-reported among the 410 participants, of which 334 (81.5%) were injured and 131 (32.0%) experienced concussion symptoms. The rate of injury per 100 athlete-seasons was greater in defensive players (195.3) than offensive players (155.1). The most common injuries were knee and ankle ligament injuries. Most injuries were classified as severe (time loss of >4 weeks).

Conclusion:

UK university American football injuries differ markedly from those reported for US colleges. UK university players appear to have less playing experience, greater concussion risks, more severe injuries, and a greater proportion of injuries in defensive players versus offensive players.

Stature, Body Mass, and Body Mass Index in High School American Football Players: Appropriate Determinants of Obesity Prevalence?

Mendez, AI, Miramonti, AA, Gillen, ZM, McKay, BD, Leutzinger, TJ, and Cramer, JT. Stature, body mass, and BMI in high school american football players: Appropriate determinants of obesity prevalence? J Strength Cond Res 32(11): 3119-3126, 2018-The purpose of this study was to evaluate stature (HT), mass (BM), body mass index (BMI), and obesity prevalence based on BMI categories in a large sample (n = 7,175) of high school American football players enrolled as freshmen, sophomores, or juniors. Players were categorized by their positions: offensive linemen (OLs), defensive linemen (DLs), tight end, defensive end, linebacker, running back, quarterback, defensive back, and wide receiver. The HT, BM, and BMI increased as grade increased among all positions. Offensive lineman and DL had the greatest HT, BM, and BMI (p ≤ 0.05). Obesity prevalence was greatest in OL and DL. When accounting for age-related increases in BMI, BM increased to a greater degree than HT. If HT is an indirect indicator of skeletal size, although BM is more influenced by soft tissue, then the age-related BMI increases in this study may be largely accounted for by soft-tissue changes rather than skeletal growth. Although obesity prevalence in OL (94.5%) and DL (78.4%) positions was greater than all other positions as determined from BMI, it is impossible to know the allocations of fat-free and fat mass-particularly in American football athletes. If obesity continues to be defined as an unhealthy accumulation of fat, then athletes who may have a greater relative proportion of lean soft tissue should not be classified as obese using BMI (BM ÷ HT). More sophisticated, reliable, and sensitive measure of body composition, such as skinfolds, may be more appropriate field measurements.

Cardiovascular risk profile in Olympic athletes: an unexpected and underestimated risk scenario

Background

Prevalence of cardiovascular (CV) risk factors has been poorly explored in subjects regularly engaged in high-intensity exercise programmes. Our aim was, therefore, to assess the prevalence and distribution of CV risk factors in a large population of competitive athletes, to derive the characteristics of athlete’s lifestyle associated with the best CV profile.

Methods

1058 Olympic athletes (656 males, 402 females), consecutively evaluated in the period 2014–2016, represent the study population. Prevalence and distribution of CV risk factors was assessed, in relation to age, body size and sport.

Findings

Dyslipidemia was the most common risk (32%), followed by increased waist circumference (25%), positive family history (18%), smoking habit (8%), hypertension (3.8%) and hyperglycaemia (0.3%). Large subset of athletes (418, 40%) had none or 1 (414, 39%) risk factor, while only a few (39, 3.7%) had 3/4 CV risk factors. The group without risks largely comprised endurance athletes (34%). Ageing was associated with higher total and low-density lipoprotein cholesterol, triglycerides (p<0.001) and glycaemia (p=0.002) and lower high-density lipoprotein cholesterol. On multivariate logistic regression analysis, age, BMI and body fat were identified as independent predictors of increased CV risk.

Interpretation

Dyslipidemia and increased waist circumference are common in elite athletes (32% and 25%, respectively). A large proportion (40%) of athletes, mostly endurance, are totally free from risk factors. Only a minority (3%) presents a high CV risk, largely expression of lifestyle and related to modifiable CV risk factors.

A Cross-Sectional Study Assessing the Contributions of Body Fat Mass and Fat-Free Mass to Body Mass Index Scores in Male Youth Rugby Players

Background

In some sports such as rugby, a large body size is an advantage, and the desire to gain weight can bring young players to become overweight or obese. The aim of this study was to evaluate the prevalence of overweight and obesity and the contribution of body fat mass index (BFMI) and fat-free mass index (FFMI) to body mass index (BMI) changes among young male rugby players (15-a-side rugby).

Methods

The criteria of the International Obesity Task Force were used to define overweight and obesity from BMI. The method of skinfold thickness was used to assess percentage of body fat (%BF), BFMI, and FFMI. Excess body fat was defined by using BFMI and %BF above the 75th percentile. Data were grouped according to the age categories of the French Rugby Federation (U11, under 11 years; U13, under 13 years; U15, under 15 years) and to BMI status (NW normal-weight versus OW/OB overweight/obese).

Results

Overall, 32.8% of the young players were overweight, and 13.8% were obese. However, 53% of young players classified as obese and overweight by BMI had an excess body fat by using BFMI above the 75th percentile. FFMI increased significantly between U11 and U13 in both groups, without significant change in BMI and BFMI. Both groups had similar significant gains in BMI and FFMI between U13 and U15, while BFMI only increased significantly in OW/OB (+ 18.5%). The strong correlations between BMI and %BF were systematically lower than those between BMI and BFMI. FFMI was strongly or moderately associated with BFMI.

Conclusions

Chart analysis of BFMI and FFMI could be used to distinguish changes in body composition across age categories in young male rugby players classified as normal-weight, overweight, and obese by BMI.

Anthropometrics and maturity status: A preliminary study of youth football head impact biomechanics

CONTEXT

There is a paucity of head impact biomechanics research focusing on youth athletes. Little is known about how youth subconcussive head impact tolerances are related to physical size and maturation.

OBJECTIVE

To examine the effects of age, anthropometric and maturational status variability on head impact biomechanics.

DESIGN

Cross-sectional.

SETTING

Outdoor youth football facilities in South Carolina.

PARTICIPANTS

Thirty-four male recreational youth football players, 8 to 13yrs.

INTERVENTIONS

Categorized by CDC standards, independent variables were: age, height, mass, BMI, and estimated peak height velocity (PHV). Participants wore a designated head impact sensor (xPatch) on their mastoid process during practices and games.

MAIN OUTCOME MEASURES

Linear acceleration (g) and rotational acceleration (rad/s²).

RESULTS

Boys in the older age category had a greater linear (F=17.72; P<0.001) and rotational acceleration (F=10.74; P<0.001) than those in the younger category. Post-PHV boys had higher linear (F=9.09, P=0.002) and rotational (F=5.57, P=0.018) accelerations than those who were pre-PHV. Rotational, but not linear acceleration differed by height category with lowest impacts found for the tallest category, whereas both linear and rotational accelerations by mass differences favored average and heavy categories. BMI overweight boys, had the greatest linear (F=5.25; P=0.011) and rotational acceleration (F=4.13; P=0.260) means.

CONCLUSION

Post-PHV boys who were older, taller and had longer legs, but who were not heavier, had higher impacts perhaps due to the type of impacts sustained. Taller boys' heads are above their peers possibly encouraging hits in the torso region resulting in lower impact accelerations. Obese boys did not have sequential results compared to boys in the other BMI categories probably due to league rules, player position, and lack of momentum produced.

Television or unrestricted, unmonitored internet access in the bedroom and body mass index in youth athletes

AIM

To correlate television or unrestricted, unmonitored Internet access in room of sleep with body mass index (BMI).

METHODS

Cross-sectional study of athletes ≤19 years who underwent an injury prevention evaluation. Independent variables included proportion of athletes categorised as overweight or obese who answered positively to American Academy of Pediatrics recommended questions: (i) Do you have a TV in the room where you sleep? (ii) Do you have unrestricted, unmonitored access to the Internet in the room where you sleep?

RESULTS

555 athletes; 324 female; mean age 13.83 ± 2.60. Athletes with a TV in their room of sleep had higher BMI (22.73 vs. 20.54; p < 0.001), slept less hours/week (7.65 vs. 8.12; p = 0.003) and were more likely to be overweight/obese (40.32% vs. 25.52%; p = 0.022). Athletes with unrestricted, unmonitored Internet access in the room of sleep had a higher BMI (21.68 vs. 19.83; p < 0.001), slept fewer hours/week (7.58 vs. 8.60; p < 0.001) and per/weekend (9.00 vs. 9.37; p < 0.001). After adjusting for age and gender, having a TV in the room of sleep remained significantly associated with BMI and WHO criteria for overweight/obesity.

CONCLUSION

Athletes with television in their room of sleep were more likely to have higher BMI and be overweight or obese.

Anthropometrics, Physical Performance, and Injury Characteristics of Youth American Football

BACKGROUND

Prior research has described the anthropometric and physical performance characteristics of professional, collegiate, and high school American football players. Yet, little research has described these factors in American youth football and their potential relationship with injury.

PURPOSE

To characterize anthropometric and physical performance measures, describe the epidemiology of injury, and examine the association of physical performance measures with injury among children participating within age-based divisions of a large metropolitan American youth football league.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Demographic, anthropometric, and physical performance characteristics and injuries of 819 male children were collected over a 2-year period (2011-2012). Injury data were collected by the league athletic trainer (AT) and coaches. Descriptive analysis of demographic, anthropometric, and physical performance measures (40-yard sprint, pro-agility, push-ups, and vertical jump) were conducted. Incidence rates were computed for all reported injuries; rates were calculated as the number of injuries per 1000 athlete-exposures (AEs). Multinomial logistic regression was used to identify whether the categories of no injury, no-time-loss (NTL) injury, and time-loss (TL) injury were associated with physical performance measures.

RESULTS

Of the 819 original participants, 760 (92.8%) completed preseason anthropometric measures (mean ± SD: age, 11.8 ± 1.2 years; height, 157.4 ± 10.7 cm; weight, 48.7 ± 13.3 kg; experience, 2.0 ± 1.8 years); 640 (78.1%) players completed physical performance measures. The mean (±SD) 40-yard sprint and pro-agility measures of the players were 6.5 ± 0.6 and 5.7 ± 0.5 seconds, respectively; the number of push-ups and maximal vertical jump height were 16.5 ± 9.3 repetitions and 42.3 ± 8.4 cm, respectively. Players assigned to different teams within age divisions demonstrated no differences in anthropometric measures; 40-yard dash and pro-agility times differed significantly (P < .05) between players assigned to different teams. A total of 261 NTL and TL injuries were reported during 35,957 AEs (games: 22%, n = 7982 AEs; practices: 78%, n = 27,975 AEs). The overall incidence rate was 7.26 per 1000 AEs (95% CI, 6.37-8.14). Physical performance measures did not predict NTL or TL injuries (P > .05).

CONCLUSION

No practically meaningful differences existed in anthropometric or physical performance measures between teams within age-based levels of play. Findings suggest that age-only criterion for player groupings can evenly match in terms of physical performance.

Body Size Changes Among National Collegiate Athletic Association New England Division III Football Players, 1956-2014: Comparison With Age-Matched Population Controls

CONTEXT

Collegiate football programs encourage athletes to pursue high body weights.

OBJECTIVE

To examine position-dependent trends over time in body size characteristics among football players in the National Collegiate Athletic Association Division III New England Small College Athletic Conference (NESCAC) from 1956 to 2014 and to compare the observed absolute and relative changes with those in age-matched male population controls.

DESIGN

Descriptive laboratory study.

SETTING

Medical school affiliated with a NESCAC institution.

PATIENTS OR OTHER PARTICIPANTS

Football team rosters from the 10-member NESCAC schools, available as public documents, were analyzed along with body size data from general population males aged 20 to 29 years from the National Health and Nutrition Examination Survey (NHANES).

MAIN OUTCOME MEASURE(S)

Body weight, height, and calculated body mass index were evaluated using analysis of variance, linear regression, and nonlinear regression to determine the distribution features of size variables and changes associated with time (year), school, and position.

RESULTS

Among NESCAC linemen, absolute and relative changes over time in body weight and body mass index exceeded corresponding changes in the NHANES population controls. New England Small College Athletic Conference offensive linemen body weights increased by 37.5% from 1956 to 2014 (192 to 264 lb [86.4 to 118.8 kg]), compared with a 12% increase (164 to 184 lb [73.8 to 82.8 kg]) since 1961 in the NHANES population controls. Body mass index changed in parallel with body weight and exceeded 35 kg/m(2) in more than 30% of contemporary NESCAC offensive linemen. Among skill players in the NESCAC group, time-related changes in body size characteristics generally paralleled those in the NHANES controls.

CONCLUSIONS

High body weight and body mass indices were evident in offensive linemen, even among those in Division III football programs with no athletic scholarships. These characteristics may be associated with adverse cardiovascular and metabolic outcomes. We need approaches to encourage risk modification in the postfootball lifestyles of these individuals.

Bullied Status and Physical Activity in Texas Adolescents

This study examined the association between having been bullied at school during the past 6 months (“bullied status”) and not meeting physical activity (PA) recommendations of 60 minutes of daily PA during the past week among 8th- and 11th-grade Texas adolescents. Multiple logistic regression analysis was conducted to examine this association, adjusted for weight status, grade, race/ethnicity, and stratified by gender; furthermore, a significant interaction was found between bullied status and weight status. Results are presented by interaction status. Results indicated that overweight girls who reported never being bullied, as well as those who reported being bullied more than twice, had higher odds of not meeting PA recommendations than normal weight girls who were never bullied (adjusted odds ratio [AOR] = 2.12, 95% confidence interval [CI: 1.12, 3.99]; AOR = 9.18, 95% CI [2.26, 37.27], respectively). Obese girls who were bullied once or twice had higher odds of not meeting PA recommendations than normal weight girls who were never bullied (AOR = 2.89, 95% CI [1.06, 7.89]). Overweight boys who reported never being bullied had lower odds of not meeting PA recommendations than normal weight boys who were never bullied (AOR = 0.62, 95% CI [0.39, 0.97]). Conversely, obese boys who were bullied once or twice reported higher odds of not meeting PA recommendations than normal weight boys who were never bullied (AOR = 3.61, 95% CI [1.22, 10.67]). Findings from this study indicate that the association between bullied status and meeting PA recommendations is complex and may differ by gender and the interaction between bullied status and weight status.

Prevalence of metabolic syndrome among college football linemen

OBJECTIVE

To determine the prevalence of metabolic syndrome among Canadian amateur football players.

METHODS

University football players from Saskatchewan were invited to participate in this study. Each subject underwent screening for blood pressure using a BpTRU monitor, and serum cholesterol and fasting blood glucose using a Cholestech LDX analyzer. Waist circumference was recorded and body composition was measured by dual-energy x-ray absorptiometry. RESULTS were compared between linemen and non-linemen using independent sample t-tests for continuous data and chi-square for dichotomous variables.

RESULTS

Out of 39 players who consented to participate, 14% of linemen (3/21) and no non-linemen satisfied metabolic syndrome criteria. Compared to non-linemen, linemen had a higher waist circumference (108.0 vs. 82.9 cm; p<0.001), higher total body fat composition (26.4% vs. 11.2%; p<0.001), lower mean high-density lipoprotein cholesterol (0.93, vs. 1.12 mmol/L; p=0.021) and higher fasting blood glucose (5.22 vs. 4.77 mmol/L; p<0.001).

CONCLUSION

Despite their young age and participation in an elite-level athletic program, many collegiate-level football linemen had features of metabolic syndrome. Although our study focused on a single team, we suspect these trends may be consistent across the country.

Prevalence of metabolic syndrome and its components among Chinese professional athletes of strength sports with different body weight categories

Background

There is an increasing concern on cardiometabolic health in young professional athletes at heavy-weight class.

Objective

Our cross-sectional survey aimed to evaluate the prevalence of metabolic syndrome and clustering of metabolic risk factors in a population of young and active professional athletes of strength sports in China.

Methods

From July 2006 to December 2008, a total of 131 male and 130 female athletes of strength sports were enrolled. We used two criteria provided by the Chinese Diabetes Society (2004) and the National Cholesterol Education Program's Adult Treatment Panel III (2002) to define the metabolic syndrome and its individual components, respectively.

Results

Regardless of their similar ages (mean: 21 years) and exercise levels, athletes in the heaviest-weight-class with unlimited maximum body weight (UBW) boundaries (mean weight and BMI: 130 kg and 38 kg/m² for men, 110 kg and 37 kg/m² for women) had significantly higher prevalence of metabolic syndrome than did those in all other body-weight-class with limited body weight (LBW) boundaries (mean weight and BMI: 105 kg and 32 kg/m² for men, 70 kg and 26 kg/m² for women). Prevalence of metabolic syndrome using CDS criteria (UBW vs. LBW: 89% vs. 18% for men, 47% vs. 0% for women) and its individual components, including central obesity, hypertension, hypertriglyceridemia, low high-density lipoprotein-cholesterol levels, and impaired fasting glucose, were all significantly higher in athletes at the heaviest weight group with UBW than all other weight groups with LBW.

Conclusions

Our study suggests that professional athletes of strength sports at the heaviest-weight-class are at a significant increased risk of cardiometabolic disease compared with those at all other weight categories. The findings support the importance of developing and implementing the strategy of early screening, awareness, and interventions for weight-related health among young athletes.

Nutritional status, biological maturation and cardiorespiratory fitness in Azorean youth aged 11-15 years

BACKGROUND

Sex and individual differences in biological maturity status can influence height, weight, and body fat. Thus, the rigorous control of these variables seems necessary for estimating overweight and obesity in adolescents. The aims of this study were to estimate the prevalence of overweight and obesity and over-fatness in Azorean adolescents and to examine the contributions of chronological age, sex, estimated maturity status, and cardiorespiratory fitness (CRF) to the risk of overweight and obesity and over-fatness.

METHODS

The sample comprised 1,206 youth aged 11-15 years (626 boys and 580 girls) from the Azores Islands, Portugal. Body mass, stature, and skinfolds (triceps and subscapular) were measured. Body mass index (BMI) was calculated and percent fat was predicted from skinfolds. Age- and sex-specific IOTF cut-off values of the BMI defined nutritional status. Biological maturation was estimated as present height expressed as a percentage of predicted adult (mature) stature. The CRF was analyzed from the 20-m shuttle run test.

RESULTS

The total prevalence rates of overweight/obesity and over-fatness were of 31% and 27%, respectively. Low CRF (unfit) and being average and advanced in maturity status were positively and significantly associated with overweight/obesity and with risk of being over-fatness in both sexes.

CONCLUSIONS

High prevalence rates of overweight/obesity and over-fatness were identified in Azorean youth, and low CRF and advanced biological maturation were positively associated with overweight/obesity and over-fatness in our sample of adolescents.

Predicting football players' dual-energy x-ray absorptiometry body composition using standard anthropometric measures

CONTEXT

The recent increase in athlete size, particularly in football athletes of all levels, coupled with the increased health risk associated with obesity warrants continued monitoring of body composition from a health perspective in this population. Equations developed to predict percentage of body fat (%Fat) have been shown to be population specific and might not be accurate for football athletes.

OBJECTIVE

To develop multiple regression equations using standard anthropometric measurements to estimate dual-energy x-ray absorptiometry %Fat (DEXA%Fat) in collegiate football players.

DESIGN

Controlled laboratory study.

PATIENTS AND OTHER PARTICIPANTS

One hundred fifty-seven National Collegiate Athletic Association Division IA football athletes (age = 20 ± 1 years, height = 185.6 ± 6.5 cm, mass = 103.1 ± 20.4 kg, DEXA%Fat = 19.5 ± 9.1%) participated.

MAIN OUTCOME MEASURE(S)

Participants had the following measures: (1) body composition testing with dual-energy x-ray absorptiometry; (2) skinfold measurements in millimeters, including chest, triceps, subscapular, midaxillary, suprailiac, abdominal (SFAB), and thigh; and (3) standard circumference measurements in centimeters, including ankle, calf, thigh, hip (AHIP), waist, umbilical (AUMB), chest, wrist, forearm, arm, and neck. Regression analysis and fit statistics were used to determine the relationship between DEXA%Fat and each skinfold thickness, sum of all skinfold measures (SFSUM), and individual circumference measures.

RESULTS

Statistical analysis resulted in the development of 3 equations to predict DEXA%Fat: model 1, (0.178 · AHIP) + (0.097 · AUMB) + (0.089 · SFSUM) - 19.641; model 2, (0.193 · AHIP) + (0.133 · AUMB) + (0.371 · SFAB) - 23.0523; and model 3, (0.132 · SFSUM) + 3.530. The R(2) values were 0.94 for model 1, 0.93 for model 2, and 0.91 for model 3 (for all, P < .001).

CONCLUSIONS

The equations developed provide an accurate way to assess DEXA%Fat in collegiate football players using standard anthropometric measures so athletic trainers and coaches can monitor these athletes at increased health risk due to increased size.

Association between body mass index, body fat per cent and muscle power output in soccer players

The objectives of this study were to examine (a) the prevalence of overweight/obesity, (b) the relationship between body mass index (BMI) and body fat percent (BF), and (c) the association between BMI, BF and power output in adult male soccer players. Members of competitive soccer clubs (n=169, aged 22.7±4.2yr) were examined for anthropometric characteristics and body composition, and performed the physical working capacity in heart rate 170 min−1 test (PWC170), a force-velocity test (F-v) and the Wingate anaerobic test (WAnT). Based on international BMI cut-off points, 17.8% (n=30) of participants were classified as overweight. BMI was correlated with BF (r=0.67, p<0.001) and could be predicted based on the equation BF=1.193·BMI-12.24 (standard error of estimate 2.49). BMI and BF were in inverse relationship with mean power during WAnT (r=−0.30, p<0.001; r=−0.47, p<0.001, respectively). BF was also in inverse relationship with PWC170 (r=−0.26, p<0.001) and maximal power of the F-v test (r=−0.18, p=0.020).The prevalence of overweight among participants was lower than what is observed in general population. The findings confirmed previous observations on general population about the negative effect of overweight and fatness on selected parameters of physical fitness.

Elevated body mass index and body fat percentage are associated with decreased physical fitness in soccer players aged 12-14 years

Purpose

Adolescents are in increased risk for the development of obesity, while sport has been suggested as an effective means against adolescent obesity. The objectives of this study were to examine (a) the prevalence of overweightness/obesity, (b) the relationship between body mass index (BMI) and body fat percent (BF), and (c) the association between BMI, BF and physical fitness in adolescent soccer players.

Methods

Members (n=136, aged 13.1±0.6 yr) of competitive soccer clubs were examined for physical and physiological characteristics.

Results

Based on international BMI cut-off points, 19.9% (n=27) of participants were classified as overweight. BMI was highly correlated with BF (r=0.77, P<0.001). BMI and BF were in inverse relationship with aerobic power (r= − 0.29, P<0.001; r= − 0.44, P<0.001, respectively), maximal anaerobic power (r= − 0.23, P=0.009; r= − 0.47, P<0.001) and local muscular endurance (r= − 0.36, P<0.001; r= − 0.67, P<0.001).

Conclusions

The strong relationship between BMI and BF suggest the further use of BMI in adolescent soccer players. The findings confirmed previous observations in the general population about the negative effect of overweight and fatness on physical fitness. The prevalence of overweightness among participants was similar with what is observed in general population. Therefore, sport participation cannot guarantee physiological body mass and body composition, and it is necessary to prescribe exercise targeting body mass and fat control.

Elevated body mass in National Football League players linked to cognitive impairment and decreased prefrontal cortex and temporal pole activity

Obesity is a risk factor for neurodegenerative disease and has been shown to adversely affect cognitive function. Professional athletes who participate in sports, which expose them to repetitive concussions, may be at heightened risk for cognitive impairment. Here, we investigated the effects of body mass as measured by waist-to-height ratio (WHtR) on regional cerebral blood flow using single-photon emission computed tomography imaging in 38 healthy weight (WHtR mean 49.34 ± 2.8; age 58 ± 9.6) and 38 overweight (WHtR mean 58.7 ± 4.7; age 58 ± 13.3) retired National Football League football players. After matching for age and position, we used a two sample t-test to determine the differences in blood flow in healthy versus overweight subjects. Statistical parametric mapping revealed a higher WHtR ratio is associated with decreased blood flow in Brodmann areas 8, 9 and 10, brain regions involved in attention, reasoning and executive function (P<0.05, family-wise error) along with deficits in the temporal pole. Moreover, overweight athletes had significant decrease in attention (P = 0.01326), general cognitive proficiency (P = 0.012; Microcog: Assessment of Cognitive Functioning) and memory (P=0.005; Mild Cognitive Impairment Screen). The association between elevated WHtR percentage and decreased blood flow in the prefrontal cortex and temporal pole may be correlated with the decreased performance on tests of attention and memory. These findings suggest that a weight management program may be critical to the health of athletes who have been exposed to mild brain trauma during their careers.

American childhood football as a possible risk factor for cerebral infarction

Three adolescent football players who had ischemic stroke associated with football practice and play are described. The literature on stroke associated with childhood sports and football in particular is reviewed, and the multiple mechanisms by which football can contribute to ischemic stroke are discussed.

Early sport specialization: roots, effectiveness, risks

Year-round training in a single sport beginning at a relatively young age is increasingly common among youth. Contributing factors include perceptions of Eastern European sport programs, a parent's desire to give his or her child an edge, labeling youth as talented at an early age, pursuit of scholarships and professional contracts, the sporting goods and services industry, and expertise research. The factors interact with the demands of sport systems. Limiting experiences to a single sport is not the best path to elite status. Risks of early specialization include social isolation, overdependence, burnout, and perhaps risk of overuse injury. Commitment to a single sport at an early age immerses a youngster in a complex world regulated by adults, which is a setting that facilitates manipulation - social, dietary, chemical, and commercial. Youth sport must be kept in perspective. Participants, including talented young athletes, are children and adolescents with the needs of children and adolescents.

Review of cardiometabolic risk factors among current professional football and professional baseball players

Data on the development of cardiovascular disease in professional football players are conflicting. Studies have documented a higher prevalence of obesity, lower high-density lipoprotein cholesterol levels, increased left ventricular and left atrial size, and higher prevalence of metabolic syndrome in former professional football linemen compared with nonlinemen. It has been suggested that former National Football League players are at risk for early cardiovascular disease and premature death. A print media report in 2006 indicated an increased prevalence of cardiovascular disease and early mortality in professional football players compared with professional baseball players. However, there has been little scientific evaluation of cardiovascular risk factors in professional baseball players. Our data suggest that there is increased cardiovascular disease risk in football players, but this is limited to heavier linemen. In preliminary studies, baseball players do not appear to demonstrate the same increased risk. However, caution should be used in the interpretation of increased cardiovascular disease risk, as it does not necessarily translate into early increased mortality.

Metabolic syndrome and insulin resistance in Division 1 collegiate football players

PURPOSE

To estimate the prevalence of metabolic syndrome and insulin resistance in a cohort of Division 1 collegiate football players.

METHODS

Ninety football players were evaluated in a cross-sectional study to estimate the prevalence of metabolic syndrome, insulin resistance, and associated risk factors. Obesity was defined as a body fat >or=25% determined by BOD POD measurements. The National Cholesterol Education Program Adult Treatment Panel III criteria were used to estimate prevalence of metabolic syndrome. Quantitative insulin sensitivity check index calculations were performed to estimate prevalence of insulin resistance. Linear regression techniques were used to determine association between body fat percentage and other measured continuous parameters. Fisher exact test was used to determine association between nominal variables, and one-way ANOVA compared the three groups defined by position.

RESULTS

Summary measures showed a small prevalence of abnormal individual measurements. There was an association between body fat percentage and most evaluated parameters (P < 0.05). The prevalence of obesity, insulin resistance, and metabolic syndrome was 21%, 21%, and 9%, respectively. Obesity is closely associated with metabolic syndrome (P < 0.0001) and insulin resistance (P < 0.0001) in this population. All subjects with metabolic syndrome were obese, and the odds for insulin resistance in the obese group are 10.6 times the odds for the nonobese group. Linemen (n = 29) had 19 of the 19 obese subjects, 13 of the 19 subjects with insulin resistance, and all subjects with metabolic syndrome.

CONCLUSIONS

There is a strong association between obesity and both metabolic syndrome and insulin resistance in Division 1 collegiate football players. Linemen are at significant risk for metabolic syndrome and insulin resistance compared with other positions. This may be predictive of future health problems in Division 1 collegiate football players, especially linemen.

Presence of metabolic syndrome in football linemen

CONTEXT

Metabolic syndrome is a clustering of symptoms associated with abdominal obesity that demonstrates a high risk for cardiovascular disease and type II diabetes mellitus.

OBJECTIVE

To evaluate football linemen in National Collegiate Athletic Association Divisions I, II, and III schools for the presence of metabolic syndrome according to the American Heart Association/National Heart, Lung, and Blood Institute criteria as well as to document other related biomarkers.

DESIGN

Cross-sectional descriptive study.

SETTING

Three university locations on the first full day of football camp in early morning.

PATIENTS OR OTHER PARTICIPANTS

Of 76 football linemen, 70 were able to provide blood samples.

MAIN OUTCOME MEASURE(S)

Height, mass, blood pressure, upper-body skinfolds, and waist circumference were measured at various stations. Two small venous samples of blood were collected and analyzed in a hospital laboratory for fasting insulin, glucose, high-density lipoprotein, total cholesterol, triglycerides, C-reactive protein, and glycosylated hemoglobin. The last station was a verbal family history for cardiovascular disease and diabetes; also, athletes filled out a nutrition attitudes questionnaire.

RESULTS

Of the 70 athletes, 34 were identified as having metabolic syndrome according to measures of blood pressure, waist circumference, fasting glucose, high-density lipoprotein, and triglycerides. The mean total cholesterol-to-high-density lipoprotein cholesterol ratio for the group was 4.95, with 32 participants displaying values higher than 5.0. Twelve volunteers had total cholesterol levels greater than 200 mmol/L, 15 had high levels of C-reactive protein, and 9 had slightly elevated levels of glycosylated hemoglobin.

CONCLUSIONS

Although athletes might be assumed to be protected from risks of cardiovascular disease, we found a high incidence of metabolic syndrome and other associated adverse biomarkers for heart disease in collegiate football linemen. Early screening, awareness, and intervention may have favorable effects on the overall health outcomes of football linemen.

Prevalence of metabolic syndrome in retired National Football League players

The National Institute of Occupational Safety and Health mortality study of National Football League (NFL) players concluded that retired NFL linemen have an increased risk of cardiovascular death compared with both nonlinemen and the general population. Though elevated body mass index contributed to the increased cardiac risk of linemen, it could not fully account for the mortality observed, suggesting that other unmeasured cardiovascular risk factors were involved. We performed a cross-sectional prevalence study of metabolic syndrome (MS), and its individual component criteria, in 510 retired NFL players who were recruited to multicity health screenings from February 2004 through June 2006. The International Diabetes Federation criteria were used to define MS. The MS component criteria of body mass index>30 kg/m2, reduced high-density lipoprotein, and raised fasting glucose were more prevalent in linemen compared with nonlinemen (85.4% vs 50.3%, p<0.001; 42.1% vs 32.7%, p=0.04; 60.4% vs 37.6%, p<0.001, respectively). Metabolic syndrome was more prevalent in linemen compared with nonlinemen (59.8% vs 30.1%, p<0.001). In conclusion, linemen exhibited a high prevalence of MS, almost double the prevalence of their nonlinemen counterparts. These findings may partially explain the increased risk for cardiovascular death observed in retired linemen and could have significant public health implications for preprofessional training regimens and postprofessional health maintenance.