Successful performance by an athlete during competition is influenced by many factors including skill level, nutritional intake before and during competition, injury status, strategy, and mental preparation. In many sports, body size and body composition can have both a direct and indirect impact on performance. This is particularly true in American football, where athletes must be bigger and have higher amounts of body mass to play certain positions. Offensive lineman (OL) and defensive lineman (DL), as well as linebackers and tight ends, are usually the largest players on a team. This is true at both the collegiate and professional levels of competition.
In an effort to enlarge body size, football players engage in many practices to increase both overall body mass and muscle mass. As the game of football has evolved at the collegiate and professional level with a demand for bigger, stronger, and faster athletes, there is a greater emphasis on quality training, proper nutrition, and the desire to be as physically large as possible while still maximizing running speed and quickness. This has led football players to use year-round advanced training programs (22), consume nutritionally appropriate diets (2), and use performance-enhancing ergogenic aids to increase muscle size and strength (37).
In the general population, there is a strong link between excess body mass, body fat, waist circumference, and poor health (4,6,8,13,14,20,38-40 4,6,8,13,14,20,38-40 4,6,8,13,14,20,38-40 4,6,8,13,14,20,38-40 4,6,8,13,14,20,38-40 4,6,8,13,14,20,38-40 4,6,8,13,14,20,38-40 4,6,8,13,14,20,38-40 4,6,8,13,14,20,38-40). Other factors such as sedentary lifestyle, impaired fasting glucose, dyslipidemia, hypertension, age, family history, and tobacco use also play a role in determining one's health status (20). These risk factors are usually found in conjunction with increases in body mass and body fat and correlate with altered health and diseases, such as hypertension, coronary heart disease, diabetes mellitus type 2, and metabolic syndrome (4,7,13,21,27 4,7,13,21,27 4,7,13,21,27 4,7,13,21,27 4,7,13,21,27).
With the increase in body size (i.e., greater mass, more body fat, larger waist circumference), there is an increased risk for poor health. In light of this relationship, it seems appropriate to ask the following question: can a football player become too big and increase his risk for certain disease conditions? The purpose of this article is three-fold. First, to show that body mass and body fat levels of American football players have increased dramatically during the last 70 years. Second, to provide evidence that the increase in body mass and body fat observed in a subset of football players puts them at increased risk for certain diseases. Third, to recommend an evaluation and treatment plan to help these individuals reduce the risk for certain diseases during and after their playing career is over.
HOW BIG HAVE FOOTBALL PLAYERS BECOME?
Visual observation of films and the inspection of player rosters from previous decades would support the conclusion that football players in the 21st century are considerably bigger than those of the 20th century. Recently, Anzell et al. (3) have demonstrated that both college and professional football players have significantly increased body size between the years 1942 and 2011. Although most position players have increased in both height and body mass over the 70-year period, the largest gains in body mass have occurred in the OL and DL (3). At the collegiate level, linemen have increased between 0.744 and 1.98 lbs per year (95% confidence intervals), which equates to a body mass increase between 52.0 lbs and 138.9 lbs over the 70-year period. At the professional level, linemen have increased body mass between 0.21 and 1.67 lbs per year, which equates to a body mass increase between 15.0 lbs and 116.6 lbs since 1942 (3).
Table 1 illustrates changes in the body mass of collegiate and professional linemen from the 1970s to the 2000s. Although the body mass values reported in Table 1 were randomly selected from the published research articles, we attempted to maintain validity of the data by only selecting those studies in which a researcher measured the body mass data in Division 1 college football teams and professional football teams. In other words, in Table 1, we only provide data where actual measurements were made and not data collected through self-report. From the data presented, it can be observed that substantial changes in body mass have occurred during the time period supporting the belief that football players are larger now than ever before.
Self-report data can also be used to demonstrate changes in body mass among collegiate and professional football players, although it is potentially less accurate. Jacobson (24) recently provided a summary of how changes in body mass have occurred over time in collegiate football players. As supported by other studies, OL and DL have experienced the largest increase in body mass, changing from ∼192 lbs in the 1950s to ∼290 lbs in 2010 (24). Additionally, an examination of rosters of the top 25 college football teams in the country at the end of the 2014 season reveals that the average body mass of OL for the majority of teams was over 300 lbs, with the highest average weight being from the University of Mississippi where the starting offensive line averaged 334 lbs (31). An examination of rosters of the National Football League for the 2014 season demonstrated a similar profile of body mass. For example, the heaviest offensive line was from the Buffalo Bills, where the average body mass among the starters was 332 lbs (ESPN. NFL Rosters. 2014. Online Source: http://espn.go.com/nfl/players). Although the total body mass tends to vary considerably in defensive lineman (i.e., nose guards, defensive tackles, and defensive ends), it is not uncommon for the largest nose guards and defensive tackles to be in excess of 330–350 lbs.
With the increase in total body mass, there is usually an increase in the body fat percentage and the total fat mass. Although different methods of assessing body composition and body fat make it challenging to compare changes over decades of time, it is still possible to make comparisons among the different positions on a football team. Regardless of the playing level (collegiate or professional), OL and DL, when grouped together, have the highest body fat percentage and the highest total fat mass values of any position player in the team (7,31 7,31). For example, Noel et al. (32) showed that OL and DL who played for a Division I collegiate football team during the early 2000s had the highest percentage of body fat (OL: 25.4 ± 2.0%; DL: 27.4 ± 3.6%) of any position in the team. Additionally, Bosch et al. (7) showed that OL and DL who played for the Green Bay Packers during the period of 2006–2011 had the highest body fat percentage (OL: 28.8 ± 3.7%; DL: 25.2 ± 7.6%) and the highest amounts of fat mass (OL: 86.6 ± 13.2 lbs; DL: 73.4 ± 27.1 lbs) of any position on the team. Body fat has also been shown to be highest in the abdominal region. Bosch et al. (7) have shown that abdominal fat mass amounts in linemen are between 2 and 4 times greater than other position players.
It seems clear that football players have become larger over time, with the greatest gains in body mass and body fat occurring in OL and DL. Although this increase in size has been in an effort to enhance performance, an unintended side effect has been an increase in disease risk factor prevalence.
INCREASED BODY SIZE AND BODY FAT INCREASES THE DISEASE RISK
In the general population, an increase in overall body mass, body fat, and waist circumference has been demonstrated to create poor health and increase disease risk. A common disease condition observed among individuals with excess body mass and fat mass is metabolic syndrome. Metabolic syndrome is a complex disorder, caused by many risk factors, with abdominal obesity, hypertension, and insulin resistance presenting as the primary contributing risk factors (20). Physical inactivity, chronological age, hormonal imbalance, genetic or ethnic background, atherogenic dyslipidemia, a prothrombotic state, and a proinflammatory state also present as contributing factors to acquiring the condition (13,20 13,20). Metabolic syndrome is strongly related to the development of cardiovascular disease and diabetes mellitus type 2 (40); therefore, a set of clinical criteria have been established to identify this condition.
The American Heart Association and the National Heart, Lung, and Blood Institute (AHA/NHLBI) have created a set of diagnostic criteria based on clinical measures including waist circumference, triglyceride (TG) levels, high-density lipoprotein cholesterol (HDL-C) levels, resting blood pressure (BP), and fasting blood glucose level (20). A patient is diagnosed as having metabolic syndrome if they have at least 3 of these 5 clinical criteria: (1) elevated waist circumference of ≥40 inches in men and ≥35 inches in women, (2) fasting TG ≥150 mg/dL or drug treatment for elevated TGs, (3) HDL-C <40 mg/dL in men, <50 mg/dL in women, or drug treatment for reduced HDL-C, (4) systolic BP ≥130 mm Hg or diastolic BP ≥85 mm Hg or drug treatment for known hypertension, (5) fasting plasma glucose ≥100 mg/dL or drug treatment for elevated plasma glucose.
The increased body mass and waist circumference of football athletes at the collegiate and professional level is linked to having a higher risk for metabolic syndrome and cardiovascular disease. Tables 2 and 3 summarize the data from numerous studies, which have examined the prevalence of metabolic syndrome and cardiovascular disease in collegiate and professional football players. At the collegiate level, Buell et al. (8) were the first to report the presence of metabolic syndrome in football lineman. The researchers found 34 of 70 linemen (48.6% prevalence) having at least 3 risk factors for metabolic syndrome. The most common risk factor was elevated waist circumference, followed by elevated BP and abnormal lipid profile. In subsequent studies with collegiate football players, other investigators have also found strong relationships between elevated waist circumference, high body fat percentage, and the prevalence of risk factors for metabolic syndrome and cardiovascular disease (6,21,38,40 6,21,38,40 6,21,38,40 6,21,38,40).
Professional-level OL and DL have also shown a high prevalence for metabolic syndrome (30,33 30,33) and cardiovascular disease risk factors (1,18,39 1,18,39 1,18,39). Whether an elevated risk factor profile results in an increased cardiovascular mortality rate has not been definitively determined, but Baron and Rinsky (5) have shown that professional linemen had a three-fold increase in cardiovascular mortality compared with nonlinemen. Although more research needs to be conducted, there is an accumulating body of evidence that indicates both collegiate and professional linemen have a higher prevalence of metabolic syndrome and cardiovascular disease risk factors than athletes playing other positions in football.
EVALUATION AND TREATMENT PLAN TO REDUCE THE RISK FOR DISEASE
Because of the increased prevalence of metabolic syndrome and an increase in cardiovascular disease risk factors among OL and DL, it is important to create an evaluation and treatment plan to reduce the risk for disease both during and after the football athlete's career. This task falls to the all-inclusive sports medicine team, which is comprised of the appropriate professionals responsible for training and caring for the athlete. Individuals who are part of the sports medicine team include strength and conditioning coaches, certified athletic trainers, team physicians, physical therapists, nutritionists, and other allied healthcare professionals (12,22 12,22).
Professionals within a sports medicine team are most well known for providing acute and chronic care to injured athletes; however, an equally important function is to establish suitable injury and illness prevention strategies in an effort to provide effective healthcare (12,22 12,22). One of the primary roles of the sports medicine team is to regularly screen the athlete. This screening typically takes the form of a preparticipation physical examination (PPE) given by a physician or physician assistant. The goal of an effective PPE is to implement preventive healthcare and consists of the following: obtaining a family and medical history and performing a general health screening comprised of a visual acuity screening, cardiovascular screening, neurological screening, orthopedic screening, and a general medical screening. During the PPE, BP, heart rate, height, weight, and respiration rate are obtained, and a further medical screening may occur depending on the information discovered throughout the medical history questionnaires and screening. Specific aspects of a PPE include reviewing medication use and listening to the heart after asking the athlete specific questions about his/her personal history of cardiovascular disease (12).
During a PPE, noninvasive cardiac testing (e.g., electrocardiography, echocardiography, exercise stress testing) may occur, but this is not a routine aspect of a PPE unless justified by findings from the personal and family history (12). Although performing these diagnostic tests may help to prevent serious health issues from occurring, these are not cost effective in a population at relatively low risk for cardiac abnormalities. Metabolic syndrome is also not analyzed for specifically, but with the increase in prevalence of lineman with a large body mass, it may be a beneficial addition to the PPE screening. Because metabolic syndrome is classified by easily obtainable measures, a screening for metabolic syndrome may be warranted in specific athletes. We recommend that a comprehensive screening for metabolic syndrome and cardiovascular risk factors should be completed for each athlete with elevated waist circumference or a high body fat percentage to identify those athletes who could benefit from an intervention. Regular periodic screening should also be performed for those athletes who have been identified as having an elevation in disease risk factors. This is especially important for those athletes who have elevated waist circumference (8).
Individuals who are identified as having metabolic syndrome should receive an intervention program to reduce or eliminate the risk factors. In many instances, significant weight loss for an OL or DL is not an openly accepted option during his playing career, as successful performance by these individuals is largely dependent on being as big and strong as possible. Consequently, the intervention program should consist of education and other risk factor reduction. Figure 1 illustrates the process recommended for identifying and providing an intervention for those athletes with elevated risk levels.
Offensive and defensive linemen must be educated about the potential role of central adiposity in overall health (8). Excessive abdominal adiposity results in an increase in cardiometabolic risk (13,26 13,26) that leads to a higher prevalence of deaths from cardiovascular disease (16). Additionally, the strong relationship between central adiposity and diabetes mellitus type 2 requires the athlete to be knowledgeable about their current and future levels of abdominal body fat (28). If weight loss is possible (i.e., after the athlete's playing career is finished), the athlete must be educated about effective weight loss strategies, as well as how weight loss in individuals with metabolic syndrome has resulted in improved regulation of blood glucose and BP levels (10).
Athletes must also be educated about and monitored for healthy dietary intake. To reduce the risk factors for metabolic syndrome and cardiovascular disease, those athletes with excessive waist circumferences or higher levels of body fat must adhere to the following general dietary guidelines: (1) portion control, (2) selection of nutrient dense food, (3) reduction of fat intake, especially saturated and hydrogenated fats, (4) reducing sodium intake, (5) increasing consumption of fruits and vegetables, and (6) emphasizing whole grain consumption (8,29 8,29). Specific dietary guidelines can also be found for reducing BP (25) or altering blood lipid profiles (15). Because of the strong relationship between abdominal obesity and diabetes mellitus type 2, athletes with impaired fasting glucose or diagnosed insulin resistance must be attentive to nutritional intake to effectively regulate blood glucose levels (34).
Athletes who present to the sports medicine team with metabolic syndrome or cardiovascular disease risk factors should be carefully evaluated, and a treatment plan should be implemented if appropriate. This could potentially include control of risk factors with medications, if medically warranted. Reductions in elevated BP, improvements in the blood lipid profile, and control of plasma glucose levels are necessary to ensure good health of the athlete.
SUMMARY AND RECOMMENDATIONS
Collegiate- and professional-level OL and DL with excessive waist circumference and high body fat mass have a higher prevalence of metabolic syndrome and a higher risk level for cardiovascular disease than other position players. Consequently, OL and DL or any athlete with elevated levels of body fat must be monitored during and after their playing career for evidence of hypertension, diabetes mellitus type 2, and coronary heart disease. Effective identification and intervention strategies must be implemented for those athletes identified as high risk. Strength and conditioning coaches are an important part of the overall sports medicine team and play a critical role in the early identification of those athletes who are at risk.
1. Allen TW, Vogel RA, Lincoln AE, Dunn RE, Tucker AM. Body size, body composition, and cardiovascular disease risk factors in NFL players. Phys Sportsmed 38: 21–27, 2010.
2. American College of Sports Medicine, American Dietetic Association, and Dietitians of Canada. Nutrition and athletic performance. Med Sci Sports Exerc 41: 709–731, 2009.
3. Anzell AR, Potteiger JA, Kraemer WJ, Otieno S. Changes in height, body weight, and body composition in American football players from 1942 to 2011. J Strength Cond Res 27: 277–284, 2013.
4. Balady GJ, Drezner JA. Tackling cardiovascular health risks in college football players. Circulation 128: 477–480, 2013.
5. Baron S, Rinsky R. NIOSH Mortality Study of NFL Football Players: 1959–1988. Cincinnati, OH: Centers for Disease Control, National Institute of Occupational Safety and Health, 1994.
6. Borchers JR, Clem KL, Habash DL, Nagaraja HN, Stokley LM, Best TM. Metabolic syndrome and insulin resistance in division 1 collegiate football players. Med Sci Sports Exerc 41: 2105–2110, 2009.
7. Bosch TA, Burruss TP, Weir NL, Fielding KA, Engel BE, Weston TD, Dengel DR. Abdominal body composition differences in NFL football players. J Strength Cond Res 28: 3313–3319, 2014.
8. Buell JL, Calland D, Hanks F, Johnston B, Pester B, Sweeney R, Thorne R. Presence of metabolic syndrome in football lineman. J Athletic Train 43: 608–616, 2008.
9. Byrd RJ, Smith DP. Body composition, pulmonary function, and maximal oxygen consumption of college football players. J Sports Med Physical Fit 16: 301–308, 1976.
10. Carroll S, Dudfield M. What is the relationship between exercise and metabolic abnormalities? A review of the metabolic syndrome. Sports Med 34: 371–418, 2004.
11. Collins MA, Millard-Stafford ML, Sparling PB, Snow TK, Rosskopf LB, Webb SA, Omer J. Evaluation of the BOD POD for assessing body fat in collegiate football players. Med Sci Sports Exerc 31: 1350–1356, 1999.
12. Conley KM, Bolin DJ, Carek PJ, Konin JG, Neal TL, Violette D. National Athletic Trainer's Association position statement: Preparticipation physical examinations and disqualifying conditions. J Athletic Train 49: 102–120, 2014.
13. Després JP, Lemieux I, Bergeron J, Pibarot P, Mathieu P, Larose E, Rodes-Cabau J, Bertrand OF, Poirier P. Abdominal obesity and the metabolic syndrome: Contribution to global cardiometabolic risk. Arterioscler Thromb Vasc Biol 28: 1039–1049, 2008.
14. Dixit S, Hecht S, Concoff A. Cardiovascular risk factors in football players. Curr Sports Med Rep 10: 378–382, 2011.
15. Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III). Executive summary of the third report of the national cholesterol education program. JAMA 285: 2486–2497, 2001.
16. Flegal KM, Williamson DF, Pamuk ER, Rosenberg HM. Estimating deaths attributable to obesity in the United States. Am J Public Health 94: 1486–1489, 2004.
17. Fox CS, Massaro JM, Hoffmann U, Pou KM, Maurovich-Horvat P, Liu CY, Vasan RS, Murabito JM, Meigs JB, Cupples LA, Agostino RB, O'Donnell CJ. Abdominal visceral and subcutaneous adipose tissue compartments: Association with metabolic risk factors in the Framingham Heart Study. Circulation 116: 39–48, 2007.
18. Garry JP, McShane JJ. Analysis of lipoproteins and body mass index in professional football players. Prev Cardiol 4: 103–108, 2001.
19. Gettman LR, Storer TW, Ward RD. Fitness changes in professional football players during preseason conditioning. Phys Sportsmed 15: 92–101, 1987.
20. Grundy SM, Cleeman JI, Daniels SR, Donato KA, Eckel RH, Franklin BA, Gordon DJ, Krauss RM, Savage PJ, Smith SC, Spertus JA, Costa F. Diagnosis and management of the metabolic syndrome: An American Heart Association/National Heart, Lung, and Blood Institute Scientific statement: Executive summary. Circulation 112: e285–e290, 2005.
21. Haskins S, Bernhardt DT, Koscik RL. Screening for insulin resistance and cardiovascular risk in collegiate football linemen. Clin J Sport Med 21: 233–236, 2011.
22. Herring SA, Bergfeld JA, Boyd J, Brolinson PG, Chang CJ, Glover DW, Grana WA, Indelicato P, Johnson RJ, Kibler WB, Kraemer WJ, McNerney JP, Pallay RM, Tanji JL. American Academy of Family Physicians, American Academy of Orthopaedic Surgeons, American College of Sports Medicine, American Medical Society for Sports Medicine, American Orthopaedic Society for Sports Medicine and American Osteopathic Academy of Sports Medicine. The team physician and conditioning of athletes for sports: A consensus statement. Med Sci Sports Exerc 33: 1789–1793, 2001.
23. Herring SA, Kibler WB, Putukian M. Team physician consensus statement: 2013 Update. Med Sci Sports Exerc 45: 1618–1622, 2013.
24. Jacobson BH. Anthropometric cross-sectional comparisons of college football players and potential health implications. J Strength Cond Res 26: 3358–3364, 2012.
25. Joint National Committee on Prevention, Detection, and Treatment of High Blood Pressure. The seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC VII). Hypertension 157: 2413–2446, 2003.
26. Kaess BM, Pedley A, Massaro JM, Murabito J, Hoffmann U, Fox CS. The ratio of visceral to subcutaneous fat, a metric of body fat distribution, is a unique correlate of cardiometabolic risk. Diabetologia 55: 2622–2630, 2012.
27. Mathews EM, Wagner DR. Prevalence of overweight and obesity in collegiate American football players, by position. J Am Coll Health 57: 33–37, 2008.
28. McGill HC, McMahon C, Herderick EE, Zieske AW, Malcom GT, Tracy RE, Strong JP. Obesity accelerates the progression of coronary atherosclerosis in young men. Circulation 105: 2712–2718, 2002.
29. Melanson KJ. Practical dietary approaches to reducing risk of cardiovascular diseases. Am J Lifestyle Med 1: 95–98, 2007.
30. Miller MA, Croft LB, Belanger AR, Romero-Corral A, Somers VK, Roberts AJ, GOldman ME. Prevalence of metabolic syndrome in retired National Football League players. Am J Cardiol 101: 1281–1284, 2008.
32. Noel MB, VanHeest JL, Zaneteas P, Rodgers CD. Body composition in division I football players. J Strength Cond Res 17: 228–237, 2003.
33. Selden MA, Helzberg JH, Waeckerle JF, Browne JE, Brewer JH, Monaco ME, Tang F, O'Keefe JH. Cardiometabolic abnormalities in current National Football League players. Am J Cardiol 103: 969–971, 2009.
34. Sluik D, Boeing H, Montonen J, Pischon T, Kaaks R, Teucher B, Tjnneland A, Halkjaer J, Berentzen TL, Overvad K, Arriola L, Ardanaz E, Bendinelli B, Grioni S, Tumino R, Sacerdote C, Mattiello A, Spijkerman AMW, van der AD, Beulens JW, van der Schouw YT, Nilsson PM, Hedblad B, Rolandsson O, Fanks PW, Nthlings U. Associations between general and abdominal adiposity and mortality in individuals with diabetes mellitus. Am J Epidemiol 174: 22–34, 2011.
35. Smith JF, Mansfield ER. Body composition prediction in university football players. Med Sci Sports Exerc 16: 398–405, 1984.
36. Snow TK, Millard-Stafford ML, Rosskopf LB. Body composition profile of NFL football players. J Strength Cond Res 12: 146–149, 1998.
37. Spedding M, Spedding C. Drugs in sport: A scientist-athlete's perspective: From ambition to neurochemistry. Br J Pharmacol 154: 496–501, 2008.
38. Steffes GD, Megura A, Adams J, Claytor RP, Ward RM, Horn TS, Potteiger JA. Prevalence of metabolic syndrome risk factors in NCAA division I and high-school football players. J Strength Cond Res 27: 1749–1757, 2013.
39. Tucker AM, Vogel RA, Lincoln AE, Dunn RE, Ahrensfield DC, Allen TW, Castle LW, Heyer RA, Pellman EJ, Strollo PJ, Wilson PWF, Yates AP. Prevalence of cardiovascular disease risk factors among National Football League players. JAMA 301: 2111–2119, 2009.
40. Wilkerson GB, Bullard JT, Bartal DW. Identification of cardiometabolic risk among collegiate football players. J Athletic Train 45: 67–74, 2010.
41. Wilmore JH, Haskell WL. Body composition and endurance capacity of professional football players. J Applied Physiol 33: 546–567, 1972.
Keywords:© 2015 by the National Strength & Conditioning Association
body mass; waist circumference; disease risk; blood pressure; lipid profile; blood glucose