scholarly journals Fluid Consumption and Sweating in National Football League and Collegiate Football Players With Different Access to Fluids During Practice

2010 ◽  
Vol 45 (2) ◽  
pp. 128-135 ◽  
Author(s):  
Sandra Fowkes Godek ◽  
Arthur R. Bartolozzi ◽  
Chris Peduzzi ◽  
Scott Heinerichs ◽  
Eugene Garvin ◽  
...  
Keyword(s):  
National Football League ◽  
National Collegiate Athletic Association ◽  
Sweat Rate ◽  
Fluid Replacement ◽  
Football Players ◽  
Fluid Consumption ◽  
Sweat Loss ◽  
Sports Drinks ◽  
Football Team ◽  
Collegiate Football

Abstract Context: Considerable controversy regarding fluid replacement during exercise currently exists. Objective: To compare fluid turnover between National Football League (NFL) players who have constant fluid access and collegiate football players who replace fluids during water breaks in practices. Design: Observational study. Setting: Respective preseason training camps of 1 National Collegiate Athletic Association Division II (DII) football team and 1 NFL football team. Both morning and afternoon practices for DII players were 2.25 hours in length, and NFL players practiced for 2.25 hours in the morning and 1 hour in the afternoon. Environmental conditions did not differ. Patients or Other Participants: Eight NFL players (4 linemen, 4 backs) and 8 physically matched DII players (4 linemen, 4 backs) participated. Intervention(s): All players drank fluids only from their predetermined individual containers. The NFL players could consume both water and sports drinks, and the DII players could only consume water. Main Outcome Measure(s): We measured fluid consumption, sweat rate, total sweat loss, and percentage of sweat loss replaced. Sweat rate was calculated as change in mass adjusted for fluids consumed and urine produced. Results: Mean sweat rate was not different between NFL (2.1 ± 0.25 L/h) and DII (1.8 ± 0.15 L/h) players (F1,12  =  2, P  =  .18) but was different between linemen (2.3 ± 0.2 L/h) and backs (1.6 ± 0.2 L/h) (t14  =  3.14, P  =  .007). We found no differences between NFL and DII players in terms of percentage of weight loss (t7  =  −0.03, P  =  .98) or rate of fluid consumption (t7  =  −0.76, P  =  .47). Daily sweat loss was greater in DII (8.0 ± 2.0 L) than in NFL (6.4 ± 2.1 L) players (t7  =  −3, P  =  .02), and fluid consumed was also greater in DII (5.0 ± 1.5 L) than in NFL (4.0 ± 1.1 L) players (t7  =  −2.8, P  =  .026). We found a correlation between sweat loss and fluids consumed (r  =  0.79, P < .001). Conclusions: During preseason practices, the DII players drinking water at water breaks replaced the same volume of fluid (66% of weight lost) as NFL players with constant access to both water and sports drinks.

scholarly journals Sweat Rates and Fluid Turnover in Professional Football Players: A Comparison of National Football League Linemen and Backs

2008 ◽  
Vol 43 (2) ◽  
pp. 184-189 ◽  
Author(s):  
Sandra Fowkes Godek ◽  
Arthur R. Bartolozzi ◽  
Richard Burkholder ◽  
Eric Sugarman ◽  
Chris Peduzzi
Keyword(s):  
Weight Loss ◽  
National Football League ◽  
Sweat Rate ◽  
Large Body ◽  
Football Players ◽  
Practice Session ◽  
Mass Measurements ◽  
Sweat Loss ◽  
Wet Bulb Globe Temperature ◽  
Globe Temperature

Abstract Context: Many National Football League (NFL) teams practice 2 times per day over consecutive days in a hot and humid environment. Large body surface area (BSA) and use of protective equipment result in high sweat rates and total sweat loss in these football players. Objective: To compare sweat rate, sweat loss, fluid consumption, and weight loss between NFL linemen and backs during preseason practices. Design: Between-groups design. Setting: Preseason training camp with wet bulb globe temperature between 19°C and 25°C. Patients or Other Participants: Eight linemen and 4 backs and receivers participated. Main Outcome Measure(s): Data were collected during both practice sessions on 2 separate days during the first week of August. Sweat rate was calculated as change in mass adjusted for all fluids consumed between prepractice and postpractice body mass measurements and the urine produced during practice divided by the length of the practice session. Gross daily sweat losses also were calculated. Results: Height, mass, and BSA were higher in linemen than in backs. Sweat rate was also higher in linemen (2385 ± 520 mL/h) than in backs (1410 ± 660 mL/h, P < .001), as was the total volume of sweat lost during both practices in 1 day (6870 ± 1034 mL/d versus 4110 ± 2287 mL/d, P  =  .014). Compared with backs, linemen consumed more fluids during practice (2030 ± 849 mL versus 1179 ± 753 mL, P  =  .025) but produced less urine (53 ± 73 mL versus 163 ± 141 mL, P  =  .018). There was no difference in postpractice weight loss (linemen  =  −1.15 ± 0.83%, backs  =  −1.06 ± 0.76%). Conclusions: Linemen sweated at higher rates, lost larger volumes of sweat, consumed more fluids, and produced less urine during practice compared with the physically smaller backs, but they did not lose a greater percentage of body weight. Sodium losses could be considerable in NFL players during the preseason because of high daily sweat losses in backs and in linemen.

scholarly journals Predicting Football Players' Dual-Energy X-Ray Absorptiometry Body Composition Using Standard Anthropometric Measures

2012 ◽  
Vol 47 (3) ◽  
pp. 257-263 ◽  
Author(s):  
Jonathan M. Oliver ◽  
Brad S. Lambert ◽  
Steven E. Martin ◽  
John S. Green ◽  
Stephen F. Crouse
Keyword(s):  
Body Composition ◽  
Health Risk ◽  
National Collegiate Athletic Association ◽  
Skinfold Thickness ◽  
Dual Energy ◽  
Football Players ◽  
Regression Equations ◽  
Anthropometric Measures ◽  
X Ray ◽  
Collegiate Football

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 R2 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.

scholarly journals Loaded and Unloaded Marching: Implications for Fluid Replacement

2014 ◽  
Vol 7 (1) ◽  
pp. 16-21
Author(s):  
Susan Dewhurst ◽  
Melissa J. Bargh ◽  
Chester Davidson ◽  
Theodoros M. Bampouras
Keyword(s):  
Sweat Rate ◽  
Urine Osmolality ◽  
Fluid Replacement ◽  
Fluid Loss ◽  
Average Heart Rate ◽  
Healthy Male ◽  
Sweat Loss ◽  
Male Officer ◽  
Increased Risk ◽  
Temperate Environment

Marching with essential survival equipment is a fundamental military exercise. A consequence of this increased load is an increased risk of dehydration. Dehydration may have fatal consequences in a combat situation where performance must be optimal. This risk can be minimized with an understanding of the additional fluid needs of soldiers marching when loaded compared to unloaded. The aim of this study was to quantify fluid loss caused by marching with a loaded Bergen rucksack and webbing of 33.5 kg for 45 minutes when compared to unloaded carriage in eight healthy male officer cadets (age, 20.5 ± 0.9 years; body mass 80.2 ± 9.2 kg). The findings demonstrate an increased rate of sweat loss (0.6 ± 0.2 L·h-1 to 1.2 ± 0.4 L·h-1; p<0.001) and increased average heart rate (105.5 ± 17.7 beats·min-1 to 136.6 ± 28.3 beats·min-1; p<0.001) for unloaded and loaded trial respectively. Urine osmolality significantly increased pre- to postmarch (p<0.05), however there was no difference in this increase between the loaded and unloaded trial. The present study demonstrated that marching with a loaded rucksack and webbing increased sweat rate by 100% compared to the same march with no additional load. For soldiers to prevent dehydration and the potential detrimental effects on performance, fluid replacement should also be doubled when marching with loading in a temperate environment, however individual differences in sweat rate should be taken into account.

Posturing Responses in Concussions Sustained by Elite American Football Players

2020 ◽  
Vol 25 (4) ◽  
pp. 203-207
Author(s):  
Scott L. Bruce ◽  
Kyra Dorney
Keyword(s):  
Current Literature ◽  
Brain Injuries ◽  
National Football League ◽  
National Collegiate Athletic Association ◽  
American Football ◽  
Football Players ◽  
Loss Of Consciousness ◽  
Inclusion Criteria ◽  
Association Football ◽  
Football Game

Current literature indicates loss of consciousness occurs in about 10% of concussions. Posturing presentations represent brain injuries and a loss of consciousness. The purpose of this study was to observe video evidence of football-game-related concussions to determine the rate in which a posturing presentation occurs in reported concussion. Over the course of three National Football League and three National Collegiate Athletic Association football seasons, 103 videos of 805 reported concussions met the inclusion criteria; 35 videos demonstrated a posturing presentation, for a rate of 33.98%. Our study indicates that the published statistic regarding loss of consciousness (occurring only about 10% of the time) may be too conservative.

Professional Football Scouts: An Investigation of Racial Stacking

2004 ◽  
Vol 21 (4) ◽  
pp. 356-375 ◽  
Author(s):  
J. R. Woodward
Keyword(s):  
African American ◽  
National Football League ◽  
Football Players ◽  
Professional Football ◽  
White Athletes ◽  
Collegiate Football

In this article the author examines sports guides that are dedicated to critiquing collegiate football players eligible for the annual National Football League amateur draft. An effort is made to assess whether the scouts in these guides describe collegiate players in ways that correspond with U.S. race logic as articulated by Coakley (1998). More specifically, the article focuses on the mental and physical descriptions of African American and White athletes by professional scouts. The results show that African American players are more likely to be described in physical terms (rather than mental terms) than are White players in the same positions.

Sweat and Sodium Losses in NCAA Football Players: A Precursor to Heat Cramps?

2005 ◽  
Vol 15 (6) ◽  
pp. 641-652 ◽  
Author(s):  
John R. Stofan ◽  
Jeffrey J. Zachwieja ◽  
Craig A. Horswill ◽  
Robert Murray ◽  
Scott A. Anderson ◽  
...  
Keyword(s):  
Fluid Intake ◽  
Division I ◽  
Football Players ◽  
Sweat Loss ◽  
Fluid Deficit ◽  
Wide Variability ◽  
History Of ◽  
Collegiate Football ◽  
Fluid Losses ◽  
Sweat Sodium

This observational study was designed to determine whether football players with a history of heat cramps have elevated fluid and sodium losses during training. During a “two-a-day” training camp, five Division I collegiate football players (20.2 ± 1.6 y, 113 ± 20 kg) with history of heat cramps (C) were matched (weight, age, race and position) with a cohort of teammates (19.6 ± 0.6 y, 110 ± 20 kg) who had never cramped (NC). Change in body weight (adjusted by fluid intake) determined gross sweat loss. Sweat samples (forearm patch) were analyzed for sodium and potassium concentrations. Adlibitum fluid intake was measured by recording pre- and post-practice bottle weights. Average sweat sodium loss for a 2.5-h practice was projected at 5.1 ± 2.3 g (C) vs. 2.2 ± 1.7 g (NC). When averaged across two practices within the day, fluid intake was similar between groups (C: 2.6 ± 0.8 L vs. NC: 2.8 ± 0.7 L), as was gross sweat loss (C: 4.0 ± 1.1 L vs. NC: 3.5 ± 1.6 L). There was wide variability in the fluid deficit incurred for both C and NC (1.3 ± 0.9 vs. 0.7 ± 1.2%) due to fluid intake. Sweat potassium was similar between groups, but sweat sodium was two times higher in C versus NC (54.6 ± 16.2 vs. 25.3 ± 10.0 mmol/L). These data indicate that sweat sodium losses were comparatively larger in cramp-prone football players than in NC. Although both groups consumed sodium-containing fluids (on-field) and food (off-field), both appeared to experience an acute sodium deficit at the end of practices based on sweat sodium losses. Large acute sodium and fluid losses (in sweat) may be characteristic of football players with a history of heat cramping.

The Effects of Accountability on Task Accomplishment in Collegiate Football

1997 ◽  
Vol 17 (1) ◽  
pp. 40-51 ◽  
Author(s):  
Phillip Ward ◽  
Shannon Smith ◽  
Tom Sharpe
Keyword(s):  
Study Data ◽  
Football Players ◽  
The Public ◽  
Public Posting ◽  
Football Team ◽  
Practice Performance ◽  
Task Accomplishment ◽  
Withdrawal Design ◽  
Collegiate Football ◽  
Game Performance

An A-B-A-B withdrawal design was used to evaluate whether accountability, in the form of public posting, was effective in improving football players’ performance in successfully blocking the forward momentum of the defense and in running routes to a criterion at, or greater than, 90% correct. Five wide receivers on a college football team participated in the study. Data were collected during practice sessions and weekly games. The players’ game performance was not intervened on and served as a measure of both the generality of the intervention and as a product measure of the practice performance. The data show that during public posting the players’ performances met or exceeded the criterion established for practices and that this criterion performance generalized to the game setting. These results support previous findings on tasks and accountability. Moreover, the public posting intervention was easy to implement by the coaches and welcomed by the players.

scholarly journals NCAA Football Off-Season Training: Unanswered Prayers… A Prayer Answered

2017 ◽  
Vol 52 (2) ◽  
pp. 145-148 ◽  
Author(s):  
Scott Anderson
Keyword(s):  
Sickle Cell ◽  
Best Practice ◽  
National Collegiate Athletic Association ◽  
Sickle Cell Trait ◽  
Exercise Physiology ◽  
Heat Stroke ◽  
Football Players ◽  
Sport Training ◽  
Training Standards ◽  
Collegiate Football

Off-season training in year-round collegiate football is purported to be performance enhancing. Absent principles of exercise physiology, excesses in sport-training regimens pose risk to the participant athletes. Since 2000, 33 National Collegiate Athletic Association (NCAA) football players have died in sport: 27 nontraumatic deaths and 6 traumatic deaths, a ratio of 4.5 nontraumatic deaths for every traumatic death. On average, 2 NCAA football players die per season. Best practices, consensus guidelines, and precautions are ignored, elevating the risk. However, standards exist that will, if heeded, prevent nontraumatic death in athletes training for sport. Sickle cell trait status knowledge and tailored precautions are preventing deaths from exertional collapse associated with sickle cell trait. Adherence to established principles of exercise physiology and best-practice training standards, which is long overdue, will help to prevent not only deaths from exertional collapse associated with sickle cell trait but also sudden cardiac, exertional heat stroke, and asthma deaths.

Sign in / Sign up

Export Citation Format

Share Document