American College Football Players Research Articles

A Low Omega-3 Index and High AA/EPA Ratio in American College Football Players are Both Improved Following 5 Weeks of DHA-Rich Algae Oil Supplementation

Abstract Purpose Many athletes are deficient in long chain omega-3 polyunsaturated fatty acids (LC n-3 PUFA). A consequent low Omega-3 Index (O3I) and high arachidonic acid/eicosapentaenoic acid (AA/EPA) ratio increase cardiovascular disease risk and inflammation. Algae oil is a plant-based, sustainable source of LC n-3 PUFA, suitable for vegans and vegetarians. Effects of algae oil supplementation on whole blood fatty acids among athletes has not been previously reported. This study evaluated the effects of 5 weeks of DHA-rich algae oil supplementation on the whole blood fatty acid profile, O3I and AA/EPA ratio of omnivorous Division I American College Football (ACF) players. Methods: Data, including a spot blood sample, were collected at baseline for all participants (n = 47), then for a subset of players (n = 22) following a 5-week control period (usual diet) and 5 weeks of algae oil supplementation (usual diet + 1575 mg docosahexaenoic acid (DHA) + eicosapentaenoic acid (EPA) 5 days/week; average 1125 mg/day). Results: Baseline O3I was 4.3% ± 0.1% and AA/EPA ratio was 45.6 ± 23.8. After 5 weeks of algae oil supplementation, the O3I was 6.1% ± 1.0% and the AA/EPA ratio was 25.1 ± 11.6. The O3I was significantly higher and the AA/EPA ratio was significantly lower (P < 0.0001 for both) compared with both baseline and the end of the control period. The increase in O3I from baseline was correlated with calculated DHA + EPA dose per unit body mass (R = 0.641, P = 0.001). Conclusions: Algae oil supplementation for 5 weeks improved both the low baseline O3I and high AA/EPA ratio among ACF players, with body mass specific dose effects.

Objective Measures of Strain and Subjective Muscle Soreness Differ Between Positional Groups and Season Phases in American College Football.

To assess objective strain and subjective muscle soreness in "Bigs" (offensive and defensive line), "Combos" (tight ends, quarterbacks, line backers, and running backs), and "Skills" (wide receivers and defensive backs) in American college football players during off-season, fall camp, and in-season phases. Twenty-three male players were assessed once weekly (3-wk off-season, 4-wk fall camp, and 3-wk in-season) for hydroperoxides (free oxygen radical test [FORT]), antioxidant capacity (free oxygen radical defense test [FORD]), oxidative stress index (OSI), countermovement-jump flight time, Reactive Strength Index (RSI) modified, and subjective soreness. Linear mixed models analyzed the effect of a 2-within-subject-SD change between predictor and dependent variables. Compared to fall camp and in-season phases, off-season FORT (P ≤ .001 and <.001), FORD (P ≤ .001 and <.001), OSI (P ≤ .001 and <.001), flight time (P ≤ .001 and <.001), RSI modified (P ≤ .001 and <.001), and soreness (P ≤ .001 and <.001) were higher for "Bigs," whereas FORT (P ≤ .001 and <.001) and OSI (P = .02 and <.001) were lower for "Combos." FORT was higher for "Bigs" compared to "Combos" in all phases (P ≤ .001, .02, and .01). FORD was higher for "Skills" compared with "Bigs" in off-season (P = .02) and "Combos" in-season (P = .01). OSI was higher for "Bigs" compared with "Combos" (P ≤ .001) and "Skills" (P = .01) during off-season and to "Combos" in-season (P ≤ .001). Flight time was higher for "Skills" in fall camp compared with "Bigs" (P = .04) and to "Combos" in-season (P = .01). RSI modified was higher for "Skills" during off-season compared with "Bigs" (P = .02) and "Combos" during fall camp (P = .03), and in-season (P = .03). Off-season American college football training resulted in higher objective strain and subjective muscle soreness in "Bigs" compared with fall camp and during in-season compared with "Combos" and "Skills" players.

The acute effects of knee extension exercises with different contraction durations on the subsequent maximal knee extension torque among athletes with different strength levels.

Individuals with high fatigue resistance against a high-intensity conditioning activity (CA) may be able to avoid experiencing significant fatigue and enhance their voluntary performance. We examined whether the optimal contraction duration of dynamic knee extension exercises to maximize subsequent voluntary performance varies depending on the strength level of an individual. The study participants were 22 male American college football players. Initially, all participants performed a 10-s maximal isometric knee extension exercise and were classified as stronger individuals (n = 8) and weaker individuals (n = 8) based on their relative muscle strength. Each group then performed three types of dynamic CA with different contraction durations (6 s [6-CA], 12 s [12-CA], and 18 s [18-CA]) in random order. To observe the time-course changes in post-activation potentiation and performance enhancement, the twitch torques induced by electrical stimulation and isokinetic knee extension torques at 180°/s were recorded before and after each CA. The twitch torque increased at 10 s (29.5% ± 9.3%) and 1 min (18.5% ± 6.8%) after 6-CA for the stronger individuals (p < 0.05). However, no post-activation potentiation was induced in the weaker individuals in either protocol. Voluntary performance increased at 4 (7.0% ± 4.5%) and 7 (8.2% ± 4.3%) min after 18-CA for stronger individuals (p < 0.05). However, there was no post-activation performance enhancement in either protocol for weaker individuals. Thus, CA with a relatively long contraction duration was optimal to maximize the subsequent voluntary performance for stronger individuals. It remains unknown whether CAs performed with relatively short or long contraction durations were optimal for weaker individuals.

Perceptual-Motor Efficiency and Concussion History Are Prospectively Associated With Injury Occurrences Among High School and Collegiate American Football Players.

Background:After a sport-related concussion (SRC), the risk for lower extremity injury is approximately 2 times greater, and the risk for another SRC may be as much as 3 to 5 times greater.Purpose:To assess the predictive validity of screening methods for identification of individual athletes who possess an elevated risk of SRC.Study Design:Case-control study; Level of evidence, 3.Methods:Metrics derived from a smartphone flanker test software application and self-ratings of both musculoskeletal function and overall wellness were acquired from American high school and college football players before study participation. Occurrences of core or lower extremity injury (CLEI) and SRC were documented for all practice sessions and games for 1 season. Receiver operating characteristic and logistic regression analyses were used to identify variables that provided the greatest predictive accuracy for CLEI or SRC occurrence.Results:Overall, there were 87 high school and 74 American college football players included in this study. At least 1 CLEI was sustained by 45% (39/87) of high school players and 55% (41/74) of college players. Predictors of CLEI included the flanker test conflict effect ≥69 milliseconds (odds ratio [OR], 2.12; 90% CI, 1.24-3.62) and a self-reported lifetime history of SRC (OR, 1.70; 90% CI, 0.90-3.23). Of players with neither risk factor, only 38% (29/77) sustained CLEI compared with 61% (51/84) of players with 1 or both of the risk factors (OR, 2.56; 90% CI, 1.50-4.36). SRC was sustained by 7 high school players and 3 college players. Predictors of SRC included the Overall Wellness Index score ≤78 (OR, 9.83; 90% CI, 3.17-30.50), number of postconcussion symptoms ≥4 (OR, 8.35; 90% CI, 2.71-25.72), the Sport Fitness Index score ≤78 (OR, 5.16; 90% CI, 1.70-15.65), history of SRC (OR, 4.03; 90% CI, 1.35-12.03), and the flanker test inverse efficiency ratio ≥1.7 (OR, 3.19; 90% CI, 1.08-9.47).Conclusion:Survey responses and smartphone flanker test metrics predicted greater injury incidence among individual football players classified as high-risk compared with that for players with a low-risk profile.

The Association Between Alterations in Redox Homeostasis, Cortisol, and Commonly Used Objective and Subjective Markers of Fatigue in American Collegiate Football.

To assess associations between a free oxygen radical test (FORT), free oxygen radical defense test (FORD), oxidative stress index, urinary cortisol, countermovement jump (CMJ), and subjective wellness in American college football. Twenty-three male student athlete American college football players were assessed over 10 weeks: off-season conditioning (3wk), preseason camp (4wk), and in season (3wk). Assessments included a once-weekly FORT and FORD blood sample, urinary cortisol sample, CMJ assessment including flight time, reactive strength index modified and concentric impulse, and a daily subjective wellness questionnaire. Linear mixed models analyzed the effect of a 2 within-subject SD change in the predictor variable on the dependent variable. The effects were interpreted using magnitude-based inference and are presented as standardized effect size (ES) ± 90% confidence intervals. Small negative associations were observed between FORT-flight time, FORT-fatigue, FORT-soreness (ES range = -0.30 to -0.48), FORD-sleep (ES = 0.42 ± 0.29), and oxidative stress index soreness (ES = 0.56 ± 0.29). Small positive associations were observed between FORT-cortisol (ES = 0.36 ± 0.35), FORD-flight time, FORD reactive strength index modified and FORD-soreness (0.37-0.41), oxidative stress index concentric impulse (ES = 0.37 ± 0.28), and with soreness-concentric impulse, soreness-flight time, and soreness reactive strength index modified (0.33-0.59). Moderate positive associations were observed between cortisol-concentric impulse and cortisol-sleep (0.57-0.60). FORT/FORD was associated with CMJ variables and subjective wellness. Greater amounts of subjective soreness were associated with decreased CMJ performance, increased FORT and cortisol, and decreased FORD.

Season-Long Heart-Rate Variability Tracking Reveals Autonomic Imbalance in American College Football Players.

To track cardiac-autonomic functioning, indexed by heart-rate variability, in American college football players throughout a competitive period. Resting heart rate (RHR) and the natural logarithm root mean square of successive differences (LnRMSSD) were obtained throughout preseason and ∼3 times weekly leading up to the national championship among 8 linemen and 12 nonlinemen. Seated 1-minute recordings were performed via mobile device and standardized for time of day and proximity to training. Relative to preseason, linemen exhibited suppressed LnRMSSD during camp-style preparation for the playoffs (P = .041, effect size [ES] = -1.01), the week of the national semifinal (P < .001, ES = -1.27), and the week of the national championship (P = .005, ES = -1.16). As a combined group, increases in RHR (P < .001) were observed at the same time points (nonlinemen ES = 0.48-0.59, linemen ES = 1.03-1.10). For all linemen, RHR trended upward (positive slopes, R2 = .02-.77) while LnRMSSD trended downward (negative slopes, R2 = .02-.62) throughout the season. Preseason to postseason changes in RHR (r = .50, P = .025) and LnRMSSD (r = -.68, P < .001) were associated with body mass. Heart-rate variability tracking revealed progressive autonomic imbalance in the lineman position group, with individual players showing suppressed values by midseason. Attenuated parasympathetic activation is a hallmark of impaired recovery and may contribute to cardiovascular maladaptations reported to occur in linemen following a competitive season. Thus, a descending pattern may serve as an easily identifiable red flag requiring attention from performance and medical staff.

Heart Rate Variability and Training Load Among National Collegiate Athletic Association Division 1 College Football Players Throughout Spring Camp.

Flatt, AA, Esco, MR, Allen, JR, Robinson, JB, Earley, RL, Fedewa, MV, Bragg, A, Keith, CM, and Wingo, JE. Heart rate variability and training load among National Collegiate Athletic Association Division 1 college football players throughout spring camp. J Strength Cond Res 32(11): 3127-3134, 2018-The purpose of this study was to determine whether recovery of cardiac-autonomic activity to baseline occurs between consecutive-day training sessions among positional groups of a collegiate football team during Spring camp. A secondary aim was to evaluate relationships between chronic (i.e., 4-week) heart rate variability (HRV) and training load parameters. Baseline HRV (lnRMSSD_BL) was compared with HRV after ∼20 hours of recovery before next-day training (lnRMSSDpost20) among positional groups composed of SKILL (n = 11), MID-SKILL (n = 9), and LINEMEN (n = 5) with a linear mixed model and effect sizes (ES). Pearson and partial correlations were used to quantify relationships between chronic mean and coefficient of variation (CV) of lnRMSSD (lnRMSSD_chronic and lnRMSSDcv, respectively) with the mean and CV of PlayerLoad (PL_chronic and PL_cv, respectively). A position × time interaction was observed for lnRMSSD (p = 0.01). lnRMSSD_BL was higher than lnRMSSDpost20 for LINEMEN (p < 0.01; ES = large), whereas differences for SKILL and MID-SKILL were not statistically different (p > 0.05). Players with greater body mass experienced larger reductions in lnRMSSD (r = -0.62, p < 0.01). Longitudinally, lnRMSSDcv was significantly related to body mass (r = 0.48) and PL_chronic (r = -0.60). After adjusting for body mass, lnRMSSDcv and PL_chronic remained significantly related (r = -0.43). The ∼20-hour recovery time between training sessions on consecutive days may not be adequate for restoration of cardiac-parasympathetic activity to baseline among LINEMEN. Players with a lower chronic training load throughout camp experienced greater fluctuation in lnRMSSD (i.e., lnRMSSDcv) and vice versa. Thus, a capacity for greater chronic workloads may be protective against perturbations in cardiac-autonomic homeostasis among American college football players.

Functional Return to Play after Surgical Treatment of Lower-Extremity Injuries using Global Positioning System Profiles in Elite College Football Players

Category: Sports Introduction/Purpose: Return to sport criteria after surgical treatment of lower extremity injuries are highly variable and without consensus. Thigh measurements assessing atrophy, single-leg hop testing and isokinetic strength measurements are commonly used metrics when considering return to sport after surgical treatment of lower-extremity injuries. Yet, these modalities are limited in scope, as they do not fully or accurately evaluate functional movements required in elite athletics. Alternatively, using new Global Positioning System (GPS) technology, a wide breadth of functional movements can be tracked for each athlete, which can be used as a comparative self-control in the event of an injury. This data proposes a more comprehensive, dynamic and longitudinal comparison of athlete performance, which may more accurately reflect functional return to sport in elite athletes after surgery. Methods: Over a three-year period, GPS data was collected on thirteen elite American College Football players at a single FBS Subdivision University. A total of 300 data points per athlete were collected for every practice, scrimmage and game starting in spring prep and extending through regular season, and post-season play. A total of 5.7 million data points including total distance traveled, average and maximum velocity, acceleration profiles, and explosive change of direction through inertial movement analysis were prospectively collected and analyzed. Individual pre-injury GPS functional profiles for each of the thirteen athletes were used as baseline, healthy comparisons, and functional recovery was determined prospectively during return to play progression after lower extremity surgery. Return to sport was allowed when post-operative GPS profiles demonstrated equivalence or superiority of all parameters compared to pre-injury measurements. Results: All thirteen players returned to sport after all measured parameters were equal to or greater than pre-injury levels. Conclusion: Modern GPS technology employed during preseason, regular season and post-season establishes an individualized, baseline, profile of lower-extremity function which allows for postoperative comparison and prospective assessment of safe return to play in elite football players.

Relationship Between Pretraining Subjective Wellness Measures, Player Load, and Rating-of-Perceived-Exertion Training Load in American College Football.

The relationship between pretraining subjective wellness and external and internal training load in American college football is unclear. To examine the relationship of pretraining subjective wellness (sleep quality, muscle soreness, energy, wellness Z score) with player load and session rating of perceived exertion (s-RPE-TL) in American college football players. Subjective wellness (measured using 5-point, Likert-scale questionnaires), external load (derived from GPS and accelerometry), and s-RPE-TL were collected during 3 typical training sessions per week for the second half of an American college football season (8wk). The relationship of pretraining subjective wellness with player load and s-RPE training load was analyzed using linear mixed models with a random intercept for athlete and a random slope for training session. Standardized mean differences (SMDs) denote the effect magnitude. A 1-unit increase in wellness Z score and energy was associated with trivial 2.3% (90% confidence interval [CI] 0.5, 4.2; SMD 0.12) and 2.6% (90% CI 0.1, 5.2; SMD 0.13) increases in player load, respectively. A 1-unit increase in muscle soreness (players felt less sore) corresponded to a trivial 4.4% (90% CI -8.4, -0.3; SMD -0.05) decrease in s-RPE training load. Measuring pretraining subjective wellness may provide information about players' capacity to perform in a training session and could be a key determinant of their response to the imposed training demands American college football. Hence, monitoring subjective wellness may aid in the individualization of training prescription in American college football players.

Not Just an Athlete: The Impact of High School Coaches on the Educational Pursuit of First-year African American College Football Players

Elite high school football players face a barrage of pressures from their external environment that determine where they attend college as well as what factors, whether academic or athletic, they consider in a school. This study aims to analyze the relationship between African American high school football players, who go on to play intercollegiate football, and their high school football coaches. African American freshmen football players at a predominantly white institution in the Southwest United States were interviewed. The responses were compared and analyzed using two tenants of critical race theory (CRT): the centrality of experiential knowledge and the challenge to the dominant ideology. In an educational context, CRT utilizes storytelling and the experiences of people of color to highlight their experiences against the dominant culture in order to transform the educational environment for the benefit of marginalized people. After analyzing the interview transcriptions, the researchers found that these athletes were positively influenced by their high school coaches to perform well academically in high school, as well as to consider academics as a major point of emphasis in choosing to attend a university. Athletes developed positive relationships with their coaches, regardless of the sport in which they coached, that encouraged them to perform well academically and see college as a means to attain a degree as opposed to an avenue to professional athletics. This positive relationship contrasted some previous literature about college students that suggested that college coach–athlete relationship could be a major source of exploitation and stress for the athletes. Overall, the research found that these coaches were a source of positive influence on these student–athlete's lives athletically, personally, and academically.

Allometric Scaling of Upper-Body Strength in Three Divisions of American College Football Players

Allometric Scaling of Upper-Body Strength in Three Divisions of American College Football Players

Sickle Cell Trait Associated With Sudden Death in Competitive Athletes

Sickle cell trait (SCT; hemoglobin AS) occurs in 8% of African Americans and although typically benign has been associated with sudden death in military recruits during intense physical activity. However, the role of SCT in the deaths of trained athletes is less well documented or acknowledged. The 31-year United States Sudden Death in Athletes Registry was interrogated to determine the frequency, epidemiology, and clinical profile of SCT-related death in a large population of competitive athletes. Of 2,462 athlete deaths, 23 (0.9% overall, 3.3% of African Americans) occurred in association with SCT: ages 12 to 22 years, 21 male (91%), and all African Americans. SCT diagnosis was made by solubility testing (n = 13) and/or hemoglobin electrophoresis (n = 16). Most victims competed in college (n = 17) and in football (n = 19). Of 271 African American football deaths in the registry, 7% (1 in 14) were known to be associated with SCT. Each athlete experienced distinctive noninstantaneous collapse with gradual deterioration over several minutes associated with vigorous or exhaustive physical exertion, usually during conditioning drills (n = 22) and typically early in the training season. Ambient temperatures were ≥80°F in 20 patients (87%), with most events in southern or border states during the summer and autumn (n = 17 [74%]). In conclusion, SCT can be associated with largely unpredictable sudden collapse and death and apparent predilection for African American college football players during conditioning. Understanding the risks, mechanisms, and event triggers of SCT may allow lifesaving alterations in training methods to be implemented.

Dietary, Anthropometric, Blood-Lipid, and Performance Patterns of American College Football Players during 8 Weeks of Training

The purpose of this study was to determine the dietary, anthropometric, blood-lipid, and performance patterns of university-level American football players attempting to increase body mass during 8 wk of training. Three-day diet records, body composition (DEXA scan), blood lipids, and performance measures were collected in redshirt football players (N = 15, age 18.5 ± 0.6 yr) early season and after 8 wk of in-season training. There was an increase (p < .05) from early-season to postseason testing for reported energy (+45%), carbohydrate (+82%), and protein (+29%) intakes and no change in the intake of fat. Fat intake was 41% of energy at the early-season test and 32% of energy at the postseason test. Increases (p < .05 for all) in performance measures, lean mass (70.5 ± 7.7-71.8 ± 7.7 kg), fat mass (15.9 ± 6.2-17.3 ± 6.8 kg), plasma total cholesterol (193.5 ± 32.4-222.6 ± 40.0 mg/dl), and low-density lipoproteins (LDL; 92.7 ± 32.7-124.5 ± 34.7 mg/dl) were measured. No changes were measured in triglycerides, very-low-density lipoproteins, or high-density lipoproteins. Increases in strength, power, speed, total body mass, muscle mass, and fat mass were measured. Cholesterol and LDL levels increased during the study to levels associated with higher risk for cardiovascular disease. It is possible that this is a temporary phenomenon, but it is cause for concern and an indication that dietary education to promote weight gain in a manner less likely to adversely affect the lipid profile is warranted.

Acute Effects of a Caffeine-Taurine Energy Drink on Repeated Sprint Performance of American College Football Players

Consumption of energy drinks is common among athletes; however, there is a lack of research on the efficacy of these beverages for short-duration, intense exercise. The purpose of this research was to investigate the acute effects of a low-calorie caffeine-taurine energy drink (AdvoCare Spark) on repeated sprint performance and anaerobic power in National Collegiate Athletic Association Division I football players. Twenty football players (age 19.7 ± 1.8 yr, height 184.9 ± 5.3 cm, weight 100.3 ± 21.7 kg) participated in a double-blind, randomized crossover study in which they received the energy drink or an isoenergetic, isovolumetric, non-caffeinated placebo in 2 trials separated by 7 days. The Running Based Anaerobic Sprint Test, consisting of six 35-m sprints with 10 s of rest between sprints, was used to assess anaerobic power. Sprint times were recorded with an automatic electronic timer. The beverage treatment did not significantly affect power (F = 3.84, p = .066) or sprint time (F = 3.06, p = .097). However, there was a significant interaction effect between caffeine use and the beverage for sprint times (F = 4.62, p = .045), as well as for anaerobic power (F = 5.40, p = .032), indicating a confounding effect. In conclusion, a caffeine-taurine energy drink did not improve the sprint performance or anaerobic power of college football players, but the level of caffeine use by the athletes likely influenced the effect of the drink.

Front Squat Data Reproducibility Collected With a Triple-Axis Accelerometer

The purpose of our study was to assess data reproducibility from 2 consecutive front squat workouts, spaced 1 week apart, performed by American college football players (n = 18) as they prepared for their competitive season. For each workout, our methods entailed the performance of 3-6 front squat repetitions per set at 55, 65, and 75% of subject's 1 repetition maximum (1RM) load. In addition, a fourth set was done at a heavier load, with a resistance equal to 80 and 83% of their 1RM values, for the first and second workouts, respectively. A triple-axis accelerometer was affixed to a barbell to quantify exercise performance. Per load, the accelerometer measures peak values for the following indices: force, velocity, and power. To assess data reproducibility, inter-workout comparisons were made for 12 performance indices with 4 statistical test-retest measures: intraclass correlation coefficients, coefficients of variation (CVs), and the SEM expressed in both absolute and relative terms. Current results show that the majority of performance indices exceeded intraclass correlation (0.75-0.80) and CV (10-15%) values previously deemed as acceptable levels of data reproducibility. The 2 indices with the greatest variability were power and velocity values obtained at 55% of the 1RM load; thus, it was concluded that higher movement rates at the lightest load were the most difficult aspect of front squat performance to repeat successfully over time. Our practical applications imply lighter loads, with inherently higher rates of barbell movement, yield lower data reproducibility values.

Anthropometry as a predictor of front squat performance in American college football players

To assess the extent anthropometry predicts front squat performance, American college football players (n = 18) performed 3-6 repetition sets at 55, 65, 75 and 80% of their 1RM (one repetition maximum) load across two workouts. At the conclusion of sets, an accelerometer (Myotest Inc., Royal Oak MI) measured peak power, force and velocity. Before the first workout, anthropometric data were collected from subjects that emphasized body segment length ratios in an attempt to predict front squat variance. Via multivariate regression, anthropometry attempted to predict the variance from each of 12 criterion variables (peak power, force and velocity at each load). With an α = 0.05, anthropometry predicted significant amounts of variance for six criterion variables, which also had high R (0.647-0.832) and R 2 (0.419-0.720) values. The same variables also yielded moderate standard error of estimates, thus anthropometry accounted for much front squat performance variance. Height/hip width ratio, body weight, body mass index and torso length were the best predictors of front squat performance. Based on current results, it was concluded anthropometry is an important predictor of front squat performance in American college football players.

Comparison Between Different Off-Season Resistance Training Programs in Division III American College Football Players

The purpose of this study was to examine the efficacy of periodization and to compare different periodization models in resistance trained American football players. Fifty-one experienced resistance trained American football players of an NCAA Division III football team (after 10 weeks of active rest) were randomly assigned to 1 of 3 groups that differed only in the manipulation of the intensity and volume of training during a 15-week offseason resistance training program. Group 1 participated in a nonperiodized (NP) training program, group 2 participated in a traditional periodized linear (PL) training program, and group 3 participated in a planned nonlinear periodized (PNL) training program. Strength and power testing occurred before training (PRE), after 7 weeks of training (MID), and at the end of the training program (POST). Significant increases in maximal (1-repetition maximum [1RM]) squat, 1RM bench press, and vertical jump were observed from PRE to MID for all groups; these increases were still significantly greater at POST; however, no MID to POST changes were seen. Significant PRE to POST improvements in the medicine ball throw (MBT) were seen for PL group only. The results do not provide a clear indication as to the most effective training program for strength and power enhancements in already trained football players. Interestingly, recovery of training-related performances was achieved after only 7 weeks of training, yet further gains were not observed. These data indicate that longer periods of training may be needed after a long-term active recovery period and that active recovery may need to be dramatically shortened to better optimize strength and power in previously trained football players.

Mucosal IgA and URTI in American College Football Players: A Year Longitudinal Study

The purpose of this study was: (a) to evaluate secretory immunoglobulin A (s-IgA) over a 12-month time period in college football players, and (b) to assess which of the commonly used standard methods of reporting s-IgA, either alone or in combination, serves as the best predictor of incidence of upper respiratory tract infection (URTI). One hundred college-aged males (75 varsity college football athletes, 25 nonfootball controls) were studied at eight points over a 12-month period. Resting mucosal IgA, protein and osmolality levels were determined from saliva using established procedures. In addition, incidence of URTI over the 12-month study duration was calculated from completed standard research logs. Repeated-measures ANOVA were conducted on the dependent variables and eight separate stepwise multiple regression analyses were conducted to predict the dependent variable "number of colds" by the independent variables, s-IgA, saliva flow rate, secretion rate of s-IgA, protein, s-IgA:protein, osmolality and s-IgA:osmolality at each data collection point. There was a significant main effect for group, time, and the group x time interaction for s-IgA, the secretion rate of s-IgA, and the number of colds. In the regression model, the only variable that made a significant contribution to the variance at all time points was the secretion rate of s-IgA. These findings suggest that a season of training in American football results in a significant decrease in both s-IgA and the secretion rate of s-IgA as well as an increase in the incidence of URTI. Among the various methods commonly employed to express s- IgA levels, the secretion rate of s-IgA may be the most useful clinical biomarker to predict the incidence of URTI.

Effects of long-term creatine supplementation on liver and kidney functions in American college football players.

The purpose of this study was to determine the effect of long-term Cr supplementation on blood parameters reflecting liver and kidney function. Twenty-three members of an NCAA Division II American football team (ages = 19-24 years) with at least 2 years of strength training experience were divided into a Cr monohydrate group (CrM, n = 10) in which they voluntarily and spontaneously ingested creatine, and a control group (n = 13) in which they took no supplements. Individuals in the CrM group averaged regular daily consumption of 5 to 20 g (mean SD = 13.9 5.8 g) for 0.25 to 5.6 years (2.9 1.8 years). Venous blood analysis for serum albumin, alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, bilirubin, urea, and creatinine produced no significant differences between groups. Creatinine clearance was estimated from serum creatinine and was not significantly different between groups. Within the CrM group, correlations between all blood parameters and either daily dosage or duration of supplementation were nonsignificant. Therefore, it appears that oral supplementation with CrM has no long-term detrimental effects on kidney or liver functions in highly trained college athletes in the absence of other nutritional supplements.