Autoregulatory progressive resistance exercise (APRE) is a method by which athletes increase strength by progressing at their own pace based on daily and weekly variations in performance, unlike traditional linear periodization (LP), where there is a set increase in intensity from week to week. This study examined whether 6 weeks of APRE was more effective at improving strength compared with traditional LP in division I College football players. We compared 23 division 1 collegiate football players (2.65 +/- 0.8 training years) who were trained using either APRE (n = 12) or LP (n = 11) during 6 weeks of preseason training in 2 separate years. After 6 weeks of training, improvements in total bench press 1 repetition maximum (1RM), squat 1RM, and repeated 225-lb bench press repetitions were compared between the APRE and LP protocol groups. Analysis of variance (ANOVA) and analysis of covariance (ANCOVA) were used to determine differences between groups. Statistical significance was accepted at p < or = 0.05. Autoregulatory progressive resistance exercise demonstrated greater improvement in 1RM bench press strength (APRE: 93.4 +/- 103 N vs. LP: -0.40 +/- 49.6 N; ANCOVA: F = 7.1, p = 0.02), estimated 1RM squat strength (APRE: 192.7 +/- 199 N vs. LP: 37.2 +/- 155 N; ANOVA: F = 4.1, p = 0.05) and the number of repetitions performed at a weight of 225 lb (APRE: 3.17 +/- 2.86 vs. LP: -0.09 +/- 2.40 repetitions; ANCOVA: F = 6.8, p = 0.02) compared with the LP group over the 6-week training period. Our findings indicate that the APRE was more effective than the LP means of programming in increasing the bench press and squat over a period of 6 weeks.

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Stress-injury models of health suggest that athletes experience more physical injuries during times of high stress. The purpose of this study was to evaluate the effect of increased physical and academic stress on injury restrictions for athletes (n = 101) on a division I college football team. Weeks of the season were categorized into 3 levels: high physical stress (HPS) (i.e., preseason), high academic stress (HAS) (i.e., weeks with regularly scheduled examinations such as midterms, finals, and week before Thanksgiving break), and low academic stress (LAS) (i.e., regular season without regularly scheduled academic examinations). During each week, we recorded whether a player had an injury restriction, thereby creating a longitudinal binary outcome. The data were analyzed using a hierarchical logistic regression model to properly account for the dependency induced by the repeated observations over time within each subject. Significance for regression models was accepted at p ≤ 0.05. We found that the odds of an injury restriction during training camp (HPS) were the greatest compared with weeks of HAS (odds ratio [OR] = 2.05, p = 0.0003) and LAS (OR = 3.65, p < 0.001). However, the odds of an injury restriction during weeks of HAS were nearly twice as high as during weeks of LAS (OR = 1.78, p = 0.0088). Moreover, the difference in injury rates reported in all athletes during weeks of HPS and weeks of HAS disappeared when considering only athletes that regularly played in games (OR = 1.13, p = 0.75) suggesting that HAS may affect athletes that play to an even greater extent than HPS. Coaches should be aware of both types of stressors and consider carefully the types of training methods imposed during times of HAS when injuries are most likely.

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 yrs; 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 (FM), lean mass (LM), android (AND) and gynoid (GYN) fat, bone mineral content (BMC), and bone 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 ± 0.027g·cm−2; all p<0.05). Across four years, weight increased significantly (Δ=6.6 ± 4.1kg), 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−2; 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.

Fat-free mass index (FFMI) is a height-adjusted assessment of fat-free mass, with previous research suggesting a natural upper limit of 25 kg·m−2 in resistance-trained males. 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 two NCAA Division I teams (n=78, n=69), and one 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−2 (mean = 23.7 ± 2.1 kg·m−2; 97.5th percentile = 28.1 kg·m−2). Differences were observed among position groups (p < 0.001; η2 = 0.25), with highest values observed in offensive and defensive linemen, and lowest values observed in offensive and defensive backs. FFMI was higher in Division I teams than Division II (24.3 ± 1.8 vs. 23.4 ± 1.8 kg·m−2; p < 0.001; d = 0.49). FFMI did not differ between age groups. Upper limit estimations for FFMI appear to vary by position; while the 97.5th percentile (28.1 kg·m−2) may represent a more suitable upper limit for the college football population as a whole, this value was exceeded by six linemen (3 OL, 3 DL), with a maximal observed value of 31.7 kg·m−2. 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.

Large strain extrusion machining (LSEM) is presented as a method of severe plastic deformation for the creation of bulk nanostructured materials. This method combines inherent advantages afforded by large strain deformation in chip formation by machining, with simultaneous dimensional control of extrusion in a single step of deformation. Bulk nanostructured materials in the form of foils, plates, and bars of controlled dimensions are shown to result by appropriately controlling the geometric parameters of the deformation in large strain extrusion machining.

College students are required to manage a variety of stressors related to academic, social, and financial commitments. In addition to the burdens facing most college students, collegiate athletes must devote a substantial amount of time to improving their sporting abilities. The strength and conditioning professional sees the athlete on nearly a daily basis and is able to recognize the changes in performance and behavior an athlete may exhibit as a result of these stressors. As such, the strength and conditioning professional may serve an integral role in the monitoring of these stressors and may be able to alter training programs to improve both performance and wellness. The purpose of this paper is to discuss stressors experienced by collegiate athletes, developing an early detection system through monitoring techniques that identify the detrimental effects of stress, and discuss appropriate stress management strategies for this population.