Relationships Between Rapid Isometric Torque Characteristics and Vertical Jump Performance in Division I Collegiate American Football Players

The purpose of this study was to examine the effects of cloth wrap (CW) and ankle tape (TAP) techniques on vertical jump performance in 29 Division I football players. There was a significant reduction in vertical jump performance for both the TAP (76.2 ± 1.3 cm; t28= 6.5, p < .0005) and CW (77.3 ± 1.3 cm; t28= 3.9, p = .001) conditions as compared with the control (78.4 ± 1.3 cm). The TAP group also had reduced vertical jump scores as compared with the CW group (t28= 4.9, p < .0005). Both prophylactic techniques resulted in decreased vertical jump capability with the TAP having a greater negative impact than the CW.

Download Full-text

Physical and performance characteristics related to starter status, position, and division in Japanese collegiate American-football players

Isokinetics and Exercise Science ◽

10.3233/ies-200222 ◽

2021 ◽

pp. 1-8

Author(s):

Junta Iguchi ◽

Minoru Matsunami ◽

Tatsuya Hojo ◽

Yoshihiko Fujisawa ◽

Kenji Kuzuhara ◽

...

Keyword(s):

Performance Test ◽

Vertical Jump ◽

American Football ◽

Football Players ◽

Jump Height ◽

Test Results ◽

Repetition Maximum ◽

Vertical Jump Height ◽

Division 1 ◽

And Performance

BACKGROUND: Few studies have investigated the variations in body composition and performance in Japanese collegiate American-football players. OBJECTIVE: To clarify what characterizes competitors at the highest levels – in the top division or on the starting lineup – we compared players’ body compositions and performance test results. METHODS: This study included 172 players. Each player’s body composition and performance (one-repetition maximum bench press, one-repetition maximum back squat, and vertical jump height) were measured; power was estimated from vertical jump height and body weight. Players were compared according to status (starter vs. non-starter), position (skill vs. linemen), and division (1 vs. 2). Regression analysis was performed to determine characteristics for being a starter. RESULTS: Players in higher divisions and who were starters were stronger and had more power, greater body size, and better performance test results. Players in skill positions were relatively stronger than those in linemen positions. Vertical jump height was a significant predictor of being a starter in Division 1. CONCLUSION: Power and vertical jump may be a deciding factor for playing as a starter or in a higher division.

Download Full-text

The Time Course of Perceptual Recovery Markers After Match Play in Division I-A College American Football

International Journal of Sports Physiology and Performance ◽

10.1123/ijspp.2016-0550 ◽

2017 ◽

Vol 12 (9) ◽

pp. 1264-1266 ◽

Cited By ~ 7

Author(s):

Hugh H.K. Fullagar ◽

Andrew Govus ◽

James Hanisch ◽

Andrew Murray

Keyword(s):

Recovery Time ◽

Time Course ◽

College Football ◽

American Football ◽

Division I ◽

Football Players ◽

Match Play ◽

Time Points ◽

The Mean ◽

Mean Differences

Purpose:To investigate the recovery time course of customized wellness markers (sleep, soreness, energy, and overall wellness) in response to match play in American Division I-A college football players. Methods:A retrospective research design was used. Wellness data were collected and analyzed for 2 American college football seasons. Perceptions of soreness, sleep, energy, and overall wellness were obtained for the day before each game (GD–1) and the days after each game (GD+2, GD+3, and GD+4). Standardized effect-size (ES) analyses ± 90% confidence intervals were used to interpret the magnitude of the mean differences between all time points for the start, middle, and finish of the season, using the following qualitative descriptors: 0–0.19 trivial, 0.2–0.59 small, 0.6–1.19 moderate, 1.2–1.99 large, <2.0 very large. Results:Overall wellness showed small ES reductions on GD+2 (d = 0.22 ± 0.09, likely [94.8%]), GD+3 (d = 0.37 ± 0.15, very likely), and GD+4 (d = 0.29 ± 0.12, very likely) compared with GD–1. There were small ES reductions for soreness between GD–1 and GD+2, GD+3, and GD +4 (d = 0.21 ± 0.09, likely, d = 0.29 ± 0.12, very likely, and 0.30 ± 0.12, very likely, respectively). Small ES reductions were also evident between GD–1 and GD+3 (d = 0.21 ± 0.09, likely) for sleep. Feelings of energy showed small ESs on GD+3 (d = 0.27 ± 0.11, very likely) and GD+4 (d = 0.22 ± 0.09, likely) compared with GD–1. Conclusion:All wellness markers were likely to very likely worse on GD+3 and GD+4 than on GD–1. These findings show that perceptual wellness takes longer than 4 d to return to pregame levels and thus should be considered when prescribing training and/or recovery.

Download Full-text

The Relationships between Internal and External Load Measures for Division I College Football Practice

Sports ◽

10.3390/sports8120165 ◽

2020 ◽

Vol 8 (12) ◽

pp. 165

Author(s):

Eric J. Sobolewski

Keyword(s):

Heart Rate ◽

External Load ◽

Perceived Exertion ◽

American Football ◽

Division I ◽

Football Players ◽

Internal Load ◽

Total Distance ◽

Meaningful Relationships ◽

Training Impulse

The aim of this study is to explore the relationships between internal and external load measures in American football. Thirty football players wore a portable integrated monitor unit for 10 weeks during the fall football season. Relationships between internal and external load measurements were determined. Internal load consisted of heart rate zones and heart rate-derived measures and session Ratings of Perceived Exertion (sRPE). External load consisted of distance in different speed zones, total distance traveled, and accelerations. There were many significant positive relationships, but the meaningful relationships (r > 0.5) were between heart rate-derived measures of load (Training Impulse and heart rate reserve) and low-intensity movement and total distance. Only accelerations between 1 and 1.99 m·s−2 were moderately correlated to heart rate-derived internal load. RPE values alone did not correlate strong enough with any of the measure but sRPE training load (sRPE-TL) correlated to most external values. Overall, moderate correlations were present between heart rate-derived internal load to total distance and lower intensity movement. sRPE-TL values had high correlations but were highly dependent on duration, not perceived exertion. When addressing load in American football, duration of the session is a key component in determining internal load as HR data and sRPE alone do not correlate highly with external loads.

Download Full-text

Effects of In-Season (5 Weeks) Creatine and Pyruvate Supplementation on Anaerobic Performance and Body Composition in American Football Players

International Journal of Sport Nutrition ◽

10.1123/ijsn.9.2.146 ◽

1999 ◽

Vol 9 (2) ◽

pp. 146-165 ◽

Cited By ~ 78

Author(s):

Michael H. Stone ◽

Kimberly Sanborn ◽

Lucille L. Smith ◽

Harold S. O'Bryant ◽

Tommy Hoke ◽

...

Keyword(s):

Body Composition ◽

Body Mass ◽

Bench Press ◽

Vertical Jump ◽

American Football ◽

Mass Composition ◽

Football Players ◽

Supplementation Period ◽

And Performance ◽

Body Mass Composition

The purpose of this investigation was to study the efficacy of two dietary supplements on measures of body mass, body composition, and performance in 42 American football players. Group CM (n = 9) received creatine monohy-drate, Group P (n = 11) received calcium pyruvate. Group COM (n = 11) received a combination of calcium pyruvate (60%) and creatine (40%), and Group PL received a placebo. Tests were performed before (Tl) and after (T2) the 5-week supplementation period, during which the subjects continued their normal training schedules. Compared to P and PL. CM and COM showed significantly greater increases for body mass, lean body mass, 1 repetition maximum (RM) bench press, combined 1 RM squat and bench press, and static vertical jump (SVJ) power output. Peak rate of force development for SVJ was significantly greater for CM compared to P and PL. Creatine and the combination supplement enhanced training adaptations associated with body mass/composition, maximum strength, and SVJ; however, pyruvate supplementation alone was ineffective.

Download Full-text

Examination of Body Mass Changes Among Division I Collegiate Football Players With Sickle Cell Trait

International Journal of Athletic Therapy & Training ◽

10.1123/ijatt.2020-0075 ◽

2021 ◽

pp. 1-6

Author(s):

Rebecca M. Hirschhorn ◽

Jessica L. Phillips Gilbert ◽

Danielle A. Cadet ◽

Tenley E. Murphy ◽

Clinton Haggard ◽

...

Keyword(s):

Body Mass ◽

Sickle Cell ◽

Student Athletes ◽

Sickle Cell Trait ◽

American Football ◽

Division I ◽

Football Players ◽

Significant Difference ◽

Body Mass Changes ◽

Collegiate Football

American football athletes are frequently hypohydrated before and during activity. Hypohydration increases the risk of exertional sickling in student-athletes with sickle cell trait (SCT). The authors examined weight charts from the 2010/2011 to 2018/2019 seasons at one Division I institution to determine if differences in percentage body mass losses (%BML) exist between those with and without SCT. Seventeen student-athletes with SCT and 17 matched-controls were included. A Bonferroni correction was applied to account for multiple comparisons (0.05/8), resulting in p < .006 considered significant. There was a significant difference for %BML between groups (SCT: 0.84 ± 0.65% vs. control: 1.21 ± 0.71%; p = .002) but not for the number of days %BML exceeded 2% (SCT: 0 ± 1 vs. control: 1 ± 1; p = .016). Implementation of proper hydration strategies minimized %BML in athletes with SCT, decreasing the risk of hypohydration and exertional sickling. The same strategies ensured all players remained below threshold to optimize performance and reduce heat illness risk.

Download Full-text

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

The Journal of Strength and Conditioning Research ◽

10.1519/jsc.0000000000001737 ◽

2017 ◽

Vol 31 (10) ◽

pp. 2719-2727 ◽

Cited By ~ 7

Author(s):

Eric T. Trexler ◽

Abbie E. Smith-Ryan ◽

Malia N.M. Blue ◽

Richard M. Schumacher ◽

Jerry L. Mayhew ◽

...

Keyword(s):

Ncaa Division I ◽

Fat Free Mass ◽

American Football ◽

Division I ◽

Football Players

Download Full-text

Positional Differences in Pre-Season Scrimmage Performance of Division I Collegiate Football Players

Sensors ◽

10.3390/s21030769 ◽

2021 ◽

Vol 21 (3) ◽

pp. 769

Author(s):

Kate S. Early ◽

Nathan P. Lemoine ◽

Annie Simoneaux ◽

Shelly Mullenix ◽

Jack Marucci ◽

...

Keyword(s):

Activity Level ◽

Burst Duration ◽

American Football ◽

Division I ◽

Football Players ◽

Activity Levels ◽

Performance Variables ◽

Specific Analysis ◽

Skill Performance ◽

Collegiate Football

This study aimed to describe the physical demands of American football players using novel performance analysis techniques. Heart rate (HR) and accelerometer-based activity levels were observed across two pre-season scrimmages in 23 Division I collegiate football players (age: 19 ± 1 y, height: 1.90 ± 0.06 m, weight: 116.2 ± 19.4 kg). Data were analyzed using a MATLAB program and inter-rater reproducibility assessed using inter-class correlations (ICC). Players were analyzed by side (offense/defense) and position (skill/non-skill). Performance variables assessed in bursts of activity included burst duration, HRmean and HRmax (bpm), and mean activity (vector magnitude units [vmu]). Exercise intensity was categorized as time spent in % HRmax in 5% increments. The burst duration (8.1±3.9 min, ICC = 0.72), HRmean (157 ± 12 bpm, ICC = 0.96) and mean activity (0.30 ± 0.05 vmu, ICC = 0.86) were reproducible. HRmean (p = 0.05) and HRmax (p = 0.001) were greater on defense. Offense spent more time at 65–70% HRmax (p = 0.01), 70–75% HRmax (p = 0.02) while defense spent more time 90–95% HRmax and ≥95% HRmax (p = 0.03). HRmean (p = 0.70) and HRpeak (p = 0.80) were not different between positions across both sides. Skilled players demonstrated greater mean activity (p = 0.02). The sport-specific analysis described HR and activity level in a reproducible manner. Automated methods of assessing HR may be useful in training and game time performance but ultimately provides support to coaching decision making.

Download Full-text

NCAA Division I American football players with sickle cell trait have altered hematological responses and hydration status

Scientific Reports ◽

10.1038/s41598-021-81473-4 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Haoyan Wang ◽

Matt Martone ◽

Michael E. Owens ◽

Nathan P. Lemoine ◽

Jack Marucci ◽

...

Keyword(s):

Uric Acid ◽

Specific Gravity ◽

Sickle Cell ◽

Ncaa Division I ◽

Sickle Cell Trait ◽

American Football ◽

Division I ◽

Urine Specific Gravity ◽

Hydration Status ◽

Football Players

AbstractSickle cell trait (SCT) is a risk factor of collapse and sudden death in athletes. We conducted a longitudinal study to determine the hematological responses and hydration status in NCAA Division I American football players with SCT. The study took place over 2 years with 6 SCT and 6 position-matched controls (CON) in year 1; and 4 SCT and 4 CON in year 2. In year 2, three of the four SCT players were recruited and re-enrolled with new position-matched controls (total sample data = 10 SCT and 10 CON). Blood samples were taken at three visits: pre-camp, post-camp, and post-season to examine hemoglobin variants, complete blood counts, and chemistry panel 26. Hydration status was assessed by measuring body weight change, urine specific gravity, and urine and sweat electrolyte concentrations during the pre-season training camp. All SCT players were confirmed to have SCT (HbS = 37.9 ± 2.4%) and had greater red cell distribution width (RDW) compared to CON across all visits. Serum uric acid was higher in SCT (7.3 ± 1.0 mg/dL) compared to CON (6.1 ± 0.6 mg/dL; p = 0.001). Furthermore, serum creatine kinase levels were greater in SCT (1617.0 ± 1034.8 IU/L) at pre-camp compared to CON (1037.4 ± 602.8 IU/L; p = 0.03). SCT players exhibited lower pre- and post-practice urine electrolytes and urine specific gravity (SCT pre: 1.019 ± 0.005 vs. CON pre: 1.026 ± 0.008 p < 0.001; SCT post: 1.020 ± 0.005 vs. CON post: 1.030 ± 0.008 p < 0.01), whereas sweat sodium concentrations were higher in SCT players (55.4 ± 13.6 mmol/L) compared to CON (45.5 ± 10.6 mmol/L; p < 0.001). Given the evidence, greater uric acid and CPK levels in SCT players compared to CON may be an early indicator of altered kidney function and muscle damage, which could be added into NCAA guidelines for surveillance among SCT players. Consistent education and reinforcement of the importance of adequate fluid balance during exercise are critical for both SCT and CON players.

Download Full-text