Changes in height, body weight, and body composition in American football players from 1942 to 2011

Kinanthropometric Characteristic Comparisons of NCAA Division I Offensive and Defensive Linemen Spanning 8 Decades

ABSTRACT

Jacobson, BH, Dawes, J, Smith, D, and Johnson, Q. Kinanthropometric characteristic comparisons of NCAA Division I offensive and defensive linemen spanning eight decades. J Strength Cond Res 36(12): 3404-3408, 2022-College football players have gained body mass, stature, and speed since the inception of the game. Of particular note is the body mass gain of NCAA Division I offensive linemen (OL) and defensive linemen (DL). The primary purpose of this study was to compare body mass and stature of OL and DL for each decade since 1950 and to subsequently compare speed using more recently available NFL Combine data to determine if the rates of gain have been consistent or is waning. Ten universities were randomly chosen from the "Power Five" conferences based on the prominence of their football programs. Recorded data included players' body mass, stature, and available 40 yd times. For each team, 8 OL and 8 DL were chosen, totaling 80 OL and 80 DL. Results indicated that body mass increased significantly ( p < 0.05) for both OL and DL (57.9 and 54.4%, respectively). However, the rate of weight gain for either OL or DL was not linear. Both OL and DL consistently increased in height from 1950 with OL and DL increasing 12.7 cm (5.0 in) and 11.4 cm (4.7 in), respectively. In addition, 40 yd times have improved over the 3 available decades (2000-2020). The 2020 times were significantly faster than the 2000 for both OL and DL. These findings may have profound implications related to player safety. The overall increases in body mass of linemen in combination with greater speed may result in have devastating consequences to the human body in a contact/collision sport such as football. Indeed, new rules are being considered to reduce debilitating injures.

Association of Playing College American Football With Long-term Health Outcomes and Mortality

IMPORTANCE

Exposure to repetitive head impacts from playing American football (including impacts resulting in symptomatic concussions and subconcussive trauma) is associated with increased risk for later-life health problems, including cognitive and neuropsychiatric decline and neurodegenerative disease. Most research on long-term health consequences of playing football has focused on former professional athletes, with limited studies of former college players.

OBJECTIVES

To estimate the prevalence of self-reported health conditions among former college football players compared with a sample of men in the general population as well as standardized mortality ratios (SMRs) among former college football players.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included data from 447 former University of Notre Dame (ND) football players aged 59 to 75 years who were seniors on the rosters from 1964 to 1980. A health outcomes survey was distributed to living players and next of kin of deceased players for whom contact information was available. The survey was completed from December 2018 to May 2019.

EXPOSURE

Participation in football at ND.

MAIN OUTCOMES AND MEASURES

Prevalence of health outcomes was compared between living former players who completed the survey and propensity score-matched participants in the Health and Retirement Study (HRS). Standardized mortality ratios of all causes and specific causes of death among all former players were compared with those among men in the general US population.

RESULTS

A total of 216 living players completed the health survey (median age, 67 years; IQR, 63-70 years) and were compared with 638 participants in the HRS (median age, 66 years; IQR, 63-70 years). Former players reported a higher prevalence of cognitive impairment (10 [5%] vs 8 [1%]; P = .02), headaches (22 [10%] vs 22 [4%]; P = .001), cardiovascular disease (70 [33%] vs 128 [20%]; P = .001), hypercholesterolemia (111 [52%] vs 182 [29%]; P = .001), and alcohol use (185 [86%] vs 489 [77%]; P = .02) and a lower prevalence of diabetes (24 [11%] vs 146 [23%]; P = .001). All-cause mortality (SMR, 0.54; 95% CI, 0.42-0.67) and mortality from heart (SMR, 0.64; 95% CI, 0.39-0.99), circulatory (SMR, 0.23; 95% CI, 0.03-0.83), respiratory (SMR, 0.13; 95% CI, 0.00-0.70), and digestive system (SMR, 0.13; 95% CI, 0.00-0.74) disorders; lung cancer (SMR, 0.26; 95% CI, 0.05-0.77); and violence (SMR, 0.10; 95% CI, 0.00-0.58) were significantly lower in the ND cohort than in the general population. Mortality from brain and other nervous system cancers was significantly higher in the ND cohort (SMR, 3.82; 95% CI, 1.04-9.77). Whereas point estimates were greater for all neurodegenerative causes (SMR, 1.42; 95% CI, 0.29-4.18), amyotrophic lateral sclerosis (SMR, 2.93; 95% CI, 0.36-10.59), and Parkinson disease (SMR, 2.07; 95% CI, 0.05-11.55), the difference did not reach statistical significance.

CONCLUSIONS AND RELEVANCE

In this cohort study of former college football players, both positive and negative health outcomes were observed. With more than 800 000 former college players living in the US, additional research appears to be needed to provide stakeholders with guidance to maximize factors that improve health outcomes and minimize factors that may increase risk for later-life morbidity and mortality.

Five-Year Trends in Reported National Football League Injuries

OBJECTIVE

To determine the incidence of all-cause injury and concussion in the National Football League (NFL) over a 5-season time span (2012-2016).

DESIGN

Prospective descriptive epidemiological study.

SETTING

National Football League Injury Report data from 2012 to 2016.

PARTICIPANTS

National Football League players.

INTERVENTIONS

None (descriptive study).

MAIN OUTCOME MEASURES

Injury report data were collected prospectively for all NFL injuries from 5 seasons (2012-2016). The incidences of reported concussions, knee injuries, and all-cause injury were compared across the 5 seasons using the Kruskal-Wallis rank-sum test.

RESULTS

A total of 10 927 injuries were identified across the 5 seasons, including 752 (6.9%) concussions. The top 3 most injured areas included the knee (17.2%), ankle (13.6%), and shoulder (8.8%). Defensive backs consistently had the highest number of all-cause injuries per season. When comparing across years, there was a significant decrease in all-cause injury in 2016 compared with 2015, a significant decrease in knee injuries in 2016 compared with 2015, and a significant increase in concussion in 2015 compared with 2014 (P < 0.05).

CONCLUSIONS

Reported all-cause injury incidence and knee injury incidence is currently on the decline. However, reported concussion incidence has recently increased, perhaps due to increased awareness and rule changes implemented to aid in the detection and treatment of concussion. Strategies to reduce injury and improve injury awareness should continue to be explored.

The possible role of hydration in concussions and long-term symptoms of concussion for athletes. A review of the evidence

The purpose of this review is to address what is known, speculated, and hypothesized regarding the issue of hydration and concussions. Based on the question, “What impact does hydration have on the relative risk for suffering concussive injuries along with long-term ramifications that have been associated with concussive (and repeated subconcussive) traumas to the cerebral cortex?,” a search of available literature was performed through June 2019. Deducing from the available literature, we can stipulate that changes in hydration within the cerebral cortex increase the likelihood for disruption of neurofilament proteins, dysregulation of membrane dynamics of the neurons and exacerbate inflammation responses following head trauma. As such, it can be speculated that differences in incidence rates may be attributed to difference in tissue fluid based on athlete demographics, level of whole-body water balance, and degree of tissue dehydration more than selection of sport. Moreover, tissue hydration in combination with other inflammation factors provides the scaffolding for the development of long-term issues (e.g. chronic traumatic encephalopathy) associated with repetitive head trauma in athletes.

Prevalence and correlates of muscle-enhancing behaviors among adolescents and young adults in the United States

OBJECTIVES

To determine the prevalence of muscle-enhancing behaviors in adolescents and young adults using a nationally representative sample in the USA and to examine differences by sex, race/ethnicity, age, socioeconomic status, body mass index, and participation in team sports.

METHODS

Prospective cohort data from the National Longitudinal Study of Adolescent to Adult Health, Waves I through III (1994-2002) were analyzed. Engagement in muscle-enhancing behaviors including dietary changes, exercise and weightlifting, supplement use, performance-enhancing substances, and anabolic androgenic steroids were recorded. Multiple logistic regression models using generalized estimating equations, incorporating robust standard errors with clustering by school and within persons, and using national sample weighting, were used to determine associations with muscle-enhancing behaviors across three data collection waves.

RESULTS

Of the 18,924 adolescents at baseline, 29.2% of males and 7.0% of females reported weight gain attempts, while 25.2% of males and 3.8% of females reported any muscle-enhancing behavior. All muscle-enhancing behaviors were more common in males compared to females (p<0.001). Among young men 18-26 years old, 15.6% reported using legal performance enhancing substances and 2.7% reported using androgenic anabolic steroids. Factors that were associated with muscle-enhancing behaviors in males across three data collection waves included Black or Hispanic/Latino race/ethnicity, age over 14 years, higher parental education, lower body mass index, and participation in team sports.

CONCLUSIONS

Muscle-enhancing behaviors ranging from dietary changes to supplement and androgenic anabolic steroid use are common among adolescent and young adult males. Clinicians should consider screening for muscle-enhancing behaviors in these populations.

Observational Study of the Associations of Participation in High School Football With Self-Rated Health, Obesity, and Pain in Adulthood

American football is the most popular high school sport in the United States, yet its association with health in adulthood has not been widely studied. We investigated the association between high school football and self-rated health, obesity, and pain in adulthood in a retrospective cohort study of data from the Wisconsin Longitudinal Study (1957-2004). We matched 925 males who played varsity football in high school with 1,521 males who did not play football. After matching, playing football was not associated with poor or fair self-rated health (odds ratio (OR) = 0.88, 95% confidence interval (CI): 0.63, 1.24; P = 0.48) or pain that limited activities (OR = 0.86, 95% CI: 0.59, 1.25; P = 0.42) at age 65 years. Football was associated with obesity (body mass index (weight (kg)height (m)2) ≥30) in adulthood (OR = 1.32, 95% CI: 1.06, 1.64; P = 0.01). The findings suggest that playing football in high school was not significantly associated with poor or fair self-related health at age 65 years, but it was associated with the risk of being obese as an adult in comparison with not playing football in high school. Our findings provide needed information about the risk of playing football with regard to a broader set of health outcomes.

Performance of Future Elite Players at the National Football League Scouting Combine

Hedlund, DP. Performance of future elite players at the NFL scouting combine. J Strength Cond Res 32(11): 3112-3118, 2018-The purpose of this study is to examine players' physical and performance measures taken at the National Football League (NFL) Scouting Combine and compare these with their future performance in the NFL. From 2002 to 2016, 3 types of player data (N = 5,506) were collected from secondary data sources. Results of players earned on various NFL Scouting Combine drills and measurements (e.g., height, body mass, 40-yard dash time, vertical jump, bench press repetitions, shuttle run time, and 3-cone drill time), the position players play on the field (e.g., quarterback, running back, wide receiver, tight end, offensive line, defensive line, linebacker, and defensive back), and if players received elite performance awards (e.g., Pro Bowl and All-Pro selections) in the future were collected. After analyzing the data, the results indicate that (a) NFL quarterbacks that received All-Pro and Pro Bowl awards tend to be taller, weigh more, run faster in the 40-yard dash, jump higher, complete more bench press reps, and are slower for the shuttle run and 3-cone drill; (b) All-Pro and Pro Bowl NFL running backs tend to weigh more, run the 40-yard dash faster, do not jump as high, complete more bench press reps, and complete the shuttle run and 3-cone drills slower; (c) NFL wide receivers who were selected for the Pro Bowl or as All-Pros tend to be taller, weigh more, run the 40-yard dash faster, have a higher vertical jump, and run the 3-cone drill faster; (d) NFL tight ends that received All-Pro and Pro Bowl awards tend to be taller, weigh more, run the 40-yard dash faster, jump higher, complete more bench press reps, run the shuttle run slower, and complete the 3-cone drill faster; (e) All-Pro and Pro Bowl NFL offensive linemen tend to run the 40-yard dash faster, jump higher, are able to complete more bench press reps, and run both the shuttle run and 3-cone drill faster; (f) NFL defensive linemen who were selected as All-Pro and Pro Bowl players tend to be taller, weigh more, run the 40-yard dash faster, jump higher, complete more bench press reps, and run the 3-cone drill faster; (g) NFL linebackers who were named to the All-Pro and Pro Bowl teams tend to be taller, weigh more, run the 40-yard dash faster, jump higher, can complete more bench press reps, and run both the shuttle run and 3-cone drill faster; and (h) NFL wide receivers that were selected for the Pro Bowl or as an All-Pro tend to weigh more, run the 40-yard dash faster, jump higher, can complete fewer bench press reps, and run the shuttle run slower. Certified strength and conditioning specialists for college and professional teams will be able to use these results to help train and set performance goals for American football athletes with whom they work and train.

Weight Gain and Health Affliction Among Former National Football League Players

BACKGROUND

Professional American-style football players are among the largest athletes across contemporary sporting disciplines. Weight gain during football participation is common, but the health implications of this early-life weight gain remain incompletely understood. We sought to define weight trajectories of former professional American-style football athletes and to establish their relationship with 5 common health afflictions (cardiovascular disease, cardiometabolic disease, neurocognitive impairment, sleep apnea, and chronic pain).

METHODS

A health survey was distributed to former National Football League (NFL) players. Former players reported body weight at 4 time points (high school, college, professional, and time of survey response) as well as maximal retirement weight. Logistic regression was used to assess associations between weight gain during football participation and health affliction.

RESULTS

In this cohort of former NFL players (n = 3,506, age 53 ± 14 years), mean weight increase from high school to time of survey response was 40 ± 36 pounds, with the majority of weight gain occurring during periods of football participation (high-school-to-college and college-to-professional). The prevalence of health afflictions ranged from 9% (cardiovascular disease) to 28% (chronic pain). Weight gain during football participation was independently associated with risk of multiple later-life health afflictions in models adjusted for football exposure, lifestyle variables, and post-career weight gain.

CONCLUSIONS

Early-life weight gain among American-style football athletes is common and is associated with risk of adverse health profiles during later-life. These findings establish football-associated weight gain as a key predictor of post-career health and raise important questions about the central role of targeted weight gain in this population.

Body Mass Index Versus Body Fat Percentage in Prospective National Football League Athletes: Overestimation of Obesity Rate in Athletes at the National Football League Scouting Combine

Provencher, MT, Chahla, J, Sanchez, G, Cinque, ME, Kennedy, NI, Whalen, J, Price, MD, Moatshe, G, and LaPrade, RF. Body mass index versus body fat percentage in prospective national football league athletes: overestimation of obesity rate in athletes at the national football league scouting combine. J Strength Cond Res 32(4): 1013-1019, 2018-Obesity has been previously noted as a major issue in the National Football League (NFL), where it has been shown that 97% of all players demonstrate a body mass index (BMI) of ≥25.0 with a reported obesity rate of 56% (BMI ≥ 30.0). However, BMI does not take into account body composition by mass, and may overestimate prevalence of obesity. The purposes of this study were (a) to determine the validity of BMI as a measure of body fat percentage and obesity in athletes at the NFL Combine, (b) to define the obesity rate based on body fat percentage compared with BMI, and (c) to determine the relationship between draft status and body composition. It was hypothesized that the rate of obesity, as measured by air displacement plethysmography (ADP), would be less than the rate of obesity as measured using BMI. Athletes who competed at the 2010 through 2016 NFL Combines were included in this study. Air displacement plethysmograph testing at the Combine was performed through BOD POD Body Composition Tracking System with collection of the following metrics: body fat percentage (%), and compared with BMI based on weight and height. In addition, the metrics were evaluated for differences over the 7-year study period to determine temporal changes and to determine draft status based on position relative to BOD POD calculations. A total of 1,958 NFL Combine participants completed ADP body composition testing. Based on BMI (≥30.0), the obesity rate was 53.4% versus an 8.9% obesity rate when using ADP. Drafted players demonstrated a significantly lower body fat percentage than undrafted players (p ≤ 0.05), with the exception of quarterbacks and running backs. All 8 positions of play, with the exception of defensive linemen, demonstrated a decrease in body fat percentage between 2010 and 2017. However, total body mass by position of play remained relatively constant with no significant change noted in any position. In conclusion, the obesity rate in prospective athletes at the NFL Combine was overestimated when calculated based on the BMI. Body fat percentage was more valid for determining an NFL player candidate's true body composition. Drafted players demonstrated a significantly lower body fat percentage in 6 of 8 positions compared with undrafted players. This is important to recognize for a strength and conditioning professional to use the correct metric when evaluating NFL players who could have been erroneously categorized in the obese population by their BMI. Furthermore, a higher percentage of fat translates to lower chances of becoming drafted.

Fat-Free Mass Index in NCAA Division I and II Collegiate American Football Players

Fat-free mass index (FFMI) is a height-adjusted assessment of fat-free mass (FFM), with previous research suggesting a natural upper limit of 25 kg·m in resistance trained male athletes. The current study evaluated upper limits for FFMI in collegiate American football players (n = 235) and evaluated differences between positions, divisions, and age groups. The sample consisted of 2 National Collegiate Athletic Association Division I teams (n = 78, n = 69) and 1 Division II team (n = 88). Body composition was assessed via dual-energy x-ray absorptiometry and used to calculate FFMI; linear regression was used to normalize values to a height of 180 cm. Sixty-two participants (26.4%) had height-adjusted FFMI values above 25 kg·m (mean = 23.7 ± 2.1 kg·m; 97.5th percentile = 28.1 kg·m). Differences were observed among position groups (p < 0.001; η = 0.25), with highest values observed in offensive linemen (OL) and defensive linemen (DL) and lowest values observed in offensive and defensive backs. Fat-free mass index was higher in Division I teams than Division II team (24.3 ± 1.8 kg·m vs. 23.4 ± 1.8 kg·m; p < 0.001; d = 0.49). Fat-free mass index did not differ between age groups. Upper limit estimations for FFMI seem to vary by position; although the 97.5th percentile (28.1 kg·m) may represent a more suitable upper limit for the college football population as a whole, this value was exceeded by 6 linemen (3 OL and 3 DL), with a maximal observed value of 31.7 kg·m. Football practitioners may use FFMI to evaluate an individual's capacity for additional FFM accretion, suitability for a specific position, potential for switching positions, and overall recruiting assessment.

Association of Playing High School Football With Cognition and Mental Health Later in Life

Importance

American football is the largest participation sport in US high schools and is a leading cause of concussion among adolescents. Little is known about the long-term cognitive and mental health consequences of exposure to football-related head trauma at the high school level.

Objective

To estimate the association of playing high school football with cognitive impairment and depression at 65 years of age.

Design, Setting, and Participants

A representative sample of male high school students who graduated from high school in Wisconsin in 1957 was studied. In this cohort study using data from the Wisconsin Longitudinal Study, football players were matched between March 1 and July 1, 2017, with controls along several baseline covariates such as adolescent IQ, family background, and educational level. For robustness, 3 versions of the control condition were considered: all controls, those who played a noncollision sport, and those who did not play any sport.

Exposures

Athletic participation in high school football.

Main Outcomes and Measures

A composite cognition measure of verbal fluency and memory and attention constructed from results of cognitive assessments administered at 65 years of age. A modified Center for Epidemiological Studies' Depression Scale score was used to measure depression. Secondary outcomes include results of individual cognitive tests, anger, anxiety, hostility, and heavy use of alcohol.

Results

Among the 3904 men (mean [SD] age, 64.4 [0.8] years at time of primary outcome measurement) in the study, after matching and model-based covariate adjustment, compared with each control condition, there was no statistically significant harmful association of playing football with a reduced composite cognition score (-0.04 reduction in cognition vs all controls; 97.5% CI, -0.14 to 0.05) or an increased modified Center for Epidemiological Studies' Depression Scale depression score (-1.75 reduction vs all controls; 97.5% CI, -3.24 to -0.26). After adjustment for multiple testing, playing football did not have a significant adverse association with any of the secondary outcomes, such as the likelihood of heavy alcohol use at 65 years of age (odds ratio, 0.68; 95% CI, 0.32-1.43).

Conclusions and Relevance

Cognitive and depression outcomes later in life were found to be similar for high school football players and their nonplaying counterparts from mid-1950s in Wisconsin. The risks of playing football today might be different than in the 1950s, but for current athletes, this study provides information on the risk of playing sports today that have a similar risk of head trauma as high school football played in the 1950s.

Longitudinal Body Composition Changes in NCAA Division I College Football Players

Trexler, ET, Smith-Ryan, AE, Mann, JB, Ivey, PA, Hirsch, KR, and Mock, MG. Longitudinal body composition changes in NCAA Division I college football players. J Strength Cond Res 31(1): 1-8, 2017-Many athletes seek to optimize body composition to fit the physical demands of their sport. American football requires a unique combination of size, speed, and power. The purpose of the current study was to evaluate longitudinal changes in body composition in Division I collegiate football players. For 57 players (mean ± SD, age = 19.5 ± 0.9 years, height = 186.9 ± 5.7 cm, weight = 107.7 ± 19.1 kg), body composition was assessed via dual-energy x-ray absorptiometry in the off-season (March-Pre), end of off-season (May), mid-July (Pre-Season), and the following March (March-Post). Outcome variables included weight, body fat percentage (BF%), fat mass, lean mass (LM), android and gynoid (GYN) fat, bone mineral content (BMC), and bone mineral density (BMD). For a subset of athletes (n = 13 out of 57), changes over a 4-year playing career were evaluated with measurements taken every March. Throughout a single year, favorable changes were observed for BF% (Δ = -1.3 ± 2.5%), LM (Δ = 2.8 ± 2.8 kg), GYN (Δ = -1.5 ± 3.0%), BMC (Δ = 0.06 ± 0.14 kg), and BMD (Δ = 0.015 ± 0.027 g·cm, all p ≤ 0.05). Across 4 years, weight increased significantly (Δ = 6.6 ± 4.1 kg) and favorable changes were observed for LM (Δ = 4.3 ± 3.0 kg), BMC (Δ = 0.18 ± 0.17 kg), and BMD (Δ = 0.033 ± 0.039 g·cm, all p ≤ 0.05). Similar patterns in body composition changes were observed for linemen and non-linemen. Results indicate that well-trained collegiate football players at high levels of competition can achieve favorable changes in body composition, even late in the career, which may confer benefits for performance and injury prevention.

Weight control practices of Division I National Collegiate Athletic Association athletes

OBJECTIVES

Altering body weight can have substantial effects on an athlete's performance and well-being. Limited information is available describing the weight control practices of Division I National Collegiate Athletic Association (NCAA) athletes.

METHODS

Weight control practices data from 188 (138 male and 50 female; 18-23 y) Division I NCAA athletes were analyzed as a part of this cross-sectional, retrospective study. Participants completed questionnaires on weight control practices and weight control nutrition knowledge at the end of their season and were classified into weight-sensitive and less weight-sensitive sports.

RESULTS

A higher proportion of females attempted to lose weight than males among less weight-sensitive sports (61% vs. 22%, chi-square = 15.8, p < 0.001). However, the prevalence of weight loss attempts was not different between females and males among weight-sensitive sports (50% vs. 60%, chi-square = 0.5, p = 0.479). The prevalence of weight gain attempts differed by gender for less weight-sensitive sports (65% vs. 4% for males and females, chi-square = 33.5, p < 0.001) but not weight-sensitive sports (24% vs. 9% for males and females, chi-square = 2.1, p = 0.146). Weight control knowledge did not differ between participants attempting versus not attempting to lose weight (Mann-Whitney U = 3340, z = -1.37, p = 0.17). Common maladaptive behaviors used to lose weight included skipping meals and exercising more than usual.

CONCLUSION

Weight loss attempts are common among Division I NCAA athletes, and the differences between males and females may be more pronounced among less weight-sensitive sports. Weight gain attempts are more common in select male sports.

Body composition and bone mineral density of collegiate American football players

The aim of this study was to compare whole and segmental body composition and bone mineral density of collegiate American football players by playing positions. Forty collegiate American football players voluntarily participated in this study. Participants were categorized by playing positions into one of five categories i.e., defensive linemen, offensive linemen, defensive secondary players, offensive secondary players and receivers. Whole body composition and bone mineral density were measured by dual x-ray absorptiometry. Offensive and defensive linemen had higher body mass, a body mass index, lean mass and a fat mass index compared to the remaining three positions and a higher lean mass index compared to offensive secondary players and receivers. Offensive linemen had a higher body fat percentage and lower values of upper to lower lean mass than offensive and defensive secondary players and receivers, and higher total mass to the lean mass ratio and fat mass to the lean mass ratio compared to the other players. Offensive linemen had a higher fat mass index and fat mass to the lean mass ratio than defensive linemen. However, in all other measures they were similar. Offensive and defensive secondary players and receivers were similar with respect to the measured variables. Bone mineral density of the players was within the normal range and no difference in lean mass was observed between the legs. In conclusion, findings of this study showed that the total and segmental body composition profile of collegiate American football players reflected the demands of particular playing positions.

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.

Physical Attributes and NFL Combine Performance Tests Between Italian National League and American Football Players: A Comparative Study

Vitale, JA, Caumo, A, Roveda, E, Montaruli, A, La Torre, A, Battaglini, CL, and Carandente, F. Physical attributes and NFL Combine performance tests between Italian National League and American football players: a comparative study. J Strength Cond Res 30(10): 2802-2808, 2016-The purpose of this study was to examine anthropometric measurements and the results of a battery of performance tests administered during the National Football League (NFL) Combine between American football players who were declared eligible to participate in the NFL Combine and football players of a top Italian team (Rhinos Milan). Participants (N = 50) were categorized by position into 1 of 3 groups based on playing position: skill players (SP) included wide receivers, cornerbacks, free safeties, strong safeties, and running backs; big skill players (BSP) consisted of fullbacks, linebackers, tight ends, and defensive ends; lineman (LM) included centers, offensive guards, offensive tackles, and defensive tackles. A 1-way analysis of variance followed by the Tukey-Kramer post hoc test was used for comparisons between Italian players by playing position. Ninety-five percent CIs were used for comparisons between American and Italian football for the NFL Combine performance tests. Significant differences for all the variables between the 3 playing categories were observed among the Italian players; LM had higher anthropometric and body composition values than SP (p < 0.001) and BSP (p < 0.001), whereas LM performed significantly worse in the physical tests, except for the 225-lb bench press test when compared with SP (p < 0.002). American football players presented significantly higher anthropometric values and test performance scores when compared with Italian players. Administrators of professional football teams in Italy need to improve the player's physical attributes, so the gap that currently exists between American and Italian players can be reduced, which could significantly improve the quality of American football in Italy.

Influence of increased body mass and body composition on cycling anaerobic power

Recent evidence suggests that not only body fat (BF) but high lean body mass (HLBM) adversely affects aerobic performance and may reduce aerobic endurance performance as well. However, the influence of body composition on anaerobic performance remains controversial. This study aimed to examine the effects of increased body mass (BM) and body composition on cycling anaerobic power. Peak power (PP) and mean power (MP) measurements were conducted in 2 groups of men with similar total BM but different body compositions resulting from (a) high level of BF [HBF group] or (b) high level of lean body mass [HLBM group] and in a control group. Peak power and MP were calculated in absolute values, relative to BM and lean body mass (LBM), and using allometric scaling. Absolute PP and MP were significantly higher in the HLBM group compared with the control and HBF groups. However, PP and MP relative to BM and using allometric scaling were similar in the HLBM and control groups, yet significantly higher than in the HBF group. There were no significant differences between groups in PP and MP when presented relative to LBM. Therefore, it seems that it is not BM but rather body composition that affects PP. Increased BM, resulting from increased LBM, does not adversely affect cycling anaerobic power, but a BM increase resulting from an increase in BF may adversely affect PP. Therefore, coaches and athletes should avoid excess BF to maximize cycling anaerobic power.

Changes in body size and physical characteristics of South African under-20 rugby union players over a 13-year period

This study compared changes in the body size and physical characteristics of South African under-20 rugby union players over a 13-year period. A total of 453 South African under-20 players (forwards: n = 256 and backs: n = 197) underwent measurements of body mass, stature, muscular strength, endurance, and 10- and 40-m sprint times. A 2-way analysis of variance was used to determine significant differences for the main effects of position (forwards vs. backs) and time (1998-2010). The pooled data showed that forwards were significantly heavier (22%), taller (5%), and stronger (18%) than the backs. However, when 1 repetition maximum strength scores were adjusted for body mass, backs were stronger per kg body mass. Stature did not change over the 13-year period for both groups. There were, however, significant increases in muscular strength (50%), body mass (20%), and muscular endurance (50%). Furthermore, an improvement in sprint times over 40 (4%) and 10 m (7%) was evident over the period of the study. In conclusion, the players became heavier, stronger, taller, and improved their upper-body muscular endurance over the 13 years of the study. Furthermore, sprint times over 10 and 40 m improved over the same time period despite the increase in body mass. It can be speculated that the changes in physical characteristics of the players over time are possibly a consequence of (a) adaptations to the changing demands of the game and (b) advancements in training methods.

Descriptive Epidemiology of Musculoskeletal Injuries and Concussions in the National Football League, 2012-2014

Background:

The risk of all-cause injury and concussion associated with football is significant. The National Football League (NFL) has implemented changes to increase player safety warranting investigation into the incidence and patterns of injury.

Purpose:

To document the incidence and patterns of all-cause injury and concussions in the NFL.

Study Design:

Descriptive epidemiology study.

Methods:

Injury data were collected prospectively from official NFL injury reports over 2 regular seasons from 2012 to 2014, with identification of injury incidence rates and patterns. Concussion rate ratios were calculated using previously reported NFL rates.

Results:

A total of 4284 injuries were identified, including 301 concussions. The all-cause injury rate was 395.8 per 1000 athletes at risk (AAR) and concussion incidence was 27.8 per 1000 AAR. Only 2.3% of team games were injury free. Wide receivers, tight ends, and defensive backs had the highest incidence of injury and concussion. Concussion incidence was 1.61-fold higher in 2012 to 2014 compared with 2002 to 2007. The knee was injured most frequently, followed by the ankle, hamstring, shoulder, and head.

Conclusion:

The incidence of all-cause injury and concussion in the NFL is significant. Concussion injury rates are higher than previous reports, potentially reflecting an improvement in recognition and awareness. Injury prevention efforts should continue to reduce the prevalence of injury associated with football.

Nutritional responses to acute training sessions in young elite rugby players

BACKGROUND

Acute exercise has been shown to induce nutritional adaptations in obese and lean inactive youth but it remains unclear whether youth with a high level of physical activity experience such exercise-induced energy intake and appetite modifications.

METHODS

14 (15- to 16-year-old) male elite rugby players completed sessions on three separate occasions: (1) a control session (CON); (2) an exercise session (EX) and; (3) a rugby session (RUGBY). The energy induced by the rugby and exercise sessions was matched (Polar Team2 pro technology), and participants' energy intake, food preferences (ad libitum buffet meals) and appetite feelings (Visual Analogue Scales) were assessed throughout the experimental days.

RESULTS

The energy intake during lunch and snack time was not different between conditions. Dinner time energy intake was significantly increased after RUBGY compared to CON with respectively 969 ± 145 kcal and 777 ± 183 kcal (p < 0.05). The energy intake at dinner time was significantly increased during EX (1185 ± 199 kcal) compared to both CON (p < 0.001) and RUGBY (p < 0.01). None of the appetite feelings investigated were modified between sessions.

CONCLUSION

Adolescent elite rugby players regulate their energy intake differently depending on the nature of their training; independently of the energy expended. This demonstrates the need for energetic and nutritional education to optimize their physical fitness and performance.

Clinical subtypes of chronic traumatic encephalopathy: literature review and proposed research diagnostic criteria for traumatic encephalopathy syndrome

The long-term consequences of repetitive head impacts have been described since the early 20th century. Terms such as punch drunk and dementia pugilistica were first used to describe the clinical syndromes experienced by boxers. A more generic designation, chronic traumatic encephalopathy (CTE), has been employed since the mid-1900s and has been used in recent years to describe a neurodegenerative disease found not just in boxers but in American football players, other contact sport athletes, military veterans, and others with histories of repetitive brain trauma, including concussions and subconcussive trauma. This article reviews the literature of the clinical manifestations of CTE from 202 published cases. The clinical features include impairments in mood (for example, depression and hopelessness), behavior (for example, explosivity and violence), cognition (for example, impaired memory, executive functioning, attention, and dementia), and, less commonly, motor functioning (for example, parkinsonism, ataxia, and dysarthria). We present proposed research criteria for traumatic encephalopathy syndrome (TES) which consist of four variants or subtypes (TES behavioral/mood variant, TES cognitive variant, TES mixed variant, and TES dementia) as well as classifications of ‘probable CTE’ and ‘possible CTE’. These proposed criteria are expected to be modified and updated as new research findings become available. They are not meant to be used for a clinical diagnosis. Rather, they should be viewed as research criteria that can be employed in studies of the underlying causes, risk factors, differential diagnosis, prevention, and treatment of CTE and related disorders.

Secular trend: morphology and performance

In a context of morphological expansion of the general population, how do athletes follow such a pattern of anthropometric growth? Is there any relation to performance? Biometric data including mass, height, body mass index (BMI) and age were collected for 50,376 American athletes representing 249,336 annual performers playing in professional baseball, football, ice hockey and basketball. Distributions by mass in National Football League (NFL) players are described by periods. Field goals have been studied in relation to players' height in the National Basketball Association (NBA). Between 1871 and 2011, athletes from the four sports have increased significantly in mass, height and BMI, following a multi-exponential function series. Consequently, biometric differences between athletes and the general population are increasing gradually. Changes in the mass distribution within the NFL show the emergence of a biometrical specificity in relation to the field position. At the professional level, performance remains structured around precise biometric values. In the NBA, a height-attractor at 201.3 ± 6.3 cm for the best scorers is invariant, regardless of the level of play. These results suggest that laws of growth and biometrics drive high-level sport and organise performance around the specific constraint of each field position. Discrepancies between some mass and height developments question the (disproportionate) large mass increase (relative to the height increase) during the 1980s and 1990s.