Multiple Models Can Concurrently Explain Fatigue During Human Performance

One of the most commonly and thoroughly studied paradigms of human performance is fatigue. However, despite volumes of research there remains considerable controversy among scientists regarding definitive conclusions about the specific mechanism(s) contributing to fatigue. Within the literature there are three primary yet distinctly different governing ideas of fatigue; the traditionally referenced central model and peripheral model as well as the emerging central governor model (CGM). The CGM has recently been advocated by a limited number of researchers and is suggestive of a more integrative model of fatigue when compared the traditional peripheral and central models. However, more work is needed to determine the specific and perhaps synergistic roles of each paradigm during exercise or sport activity. This article contains three components; (1) a brief overview of the problems associated with defining fatigue, (2) a description of the models governing interpretation of fatigue and, (3) a presentation of multiple interpretations of selected data to demonstrate that some results can be reasonably explained using multiple models of fatigue, often concurrently. The purposes of this paper are to reveal that a) perhaps it is not the results that suggest a certain paradigm of regulation, yet that it may be a product of an a priori definition that is being employed and b) an integrative model of central and peripheral fatigue may present a plausible explanation for fatigue vs. adherence to the notion that each paradigm is mutually exclusive

Sex Specific Responses to Perceptually Regulated Work-to-Rest Ratios during Resistance Training

Recovery has long been an important training variable, receiving increased attention within the scientific literature. While there has been considerable attention to intersession recovery, less is known about optimizing intrasession recovery. Additionally, growing evidence suggest women may experience relatively less fatigue with greater acute recovery as opposed to men when exercising at similar intensities. However, relatively little is known regarding the impact of self-regulated within session recovery between men and women during resistance training. PURPOSE: Therefore, the purpose of the research is to examine the sex specific responses to perceptually regulated work-to-rest ratios during strength training. METHODS: Participants (n = 14; 7 men, 7 women) completed two sessions. Session one consisted of obtaining each individual’s one-repetition maximum (1RM) for squat (SQ) and bench press (BP) using the National Strength and Conditioning Association standardized procedures. Following a minimum of 48 hours of recovery, participants performed 5 sets of 6 repetitions at 80% of their 1RM for SQ and BP (experimental session). Immediately following each set of work (SW), rating of perceived exertion (RPE) using the OMNI RPE scale for resistance training was recorded. Participants utilized the Perceived Recovery Status (PRS) scale to guide their recovery. Participants were instructed that when they reach a ‘7’ (out of 10) begin their next set. Following completion of the SQ participants were given 15 minutes before completing the same procedure for the BP. RESULTS: Results from an 1-Way ANOVA, indicate no statistically different (SQ: SW1 =0.88; SW2 p=0.18; SW3 p=0.53; SW4 p=0.19; BP: SW1 =0.09; SW2 p=0.07; SW3 p=0.28; SW4 p=0.25) time to recovery between men (SQ: SW2 109.6 ± 40.4; SW3 136.9 ± 37.4 ; SW4 191 ± 82.5; SW5 178.7 ± 79.7; BP: SW2 137.3 ± 45.9; SW3 173.6 ± 88.3; SW4 170.6 ± 133.5; SW5 194.7 ± 133.1) and women (SQ: SW2 115.6 ± 89.9; SW3 109 ± 36.5 ; SW4 111 ± 53.9; SW5 122.6 ± 69.4; BP: SW2 94.4 ± 39.3; SW3 102.1 ± 88.3; SW4 109 ± 56.2; SW5 127.4 ± 54.4). However, there was a large effect size of sex time to recovery as calculated by Cohen’s d (SQ: SW1 d =0.09; SW2 d=0.74; SW3 d =1.19; SW4 d =0.76; BP: SW1 d =1.02; SW2 d =1.15; SW3 d =0.65; SW4 d =0.72). While no statistical difference was found, the self-selected recovery time between men and women indicated women self-select shorter recovery periods on both SQ and BP, with no differences in volume of work. CONCLUSION: These findings support the notion that women may experience either relatively less fatigue during exercise or can recovery from similar intensities faster than men. Further work is needed to determine optimal work-to-rest ratios between men and women during resistance training and what implications this may have on training adaptations

Physical Fitness Sex Differences of ROTC Cadets

Occupational requirements of military personal necessitate optimal levels of physical fitness; suboptimal levels yield detrimental operations. Consequently, female physical readiness and abilities in comparison to the male soldier fitness level is frequently questioned. Qualitative reports denounce masculine advantages, however, quantitative measures explaining sex differences in physical fitness of military personal remains unclear. PURPOSE: Clarifying the physical fitness difference of male and female militants was the purpose of this investigation. METHODS: A Freedom of Information Act request provided the researchers with Army Physical Fitness Test (APFT) results (Raw 2-mile run, Raw 2-minute push-ups, Raw 2-minute sit-ups, Standardized 2-mile run, Standardized 2-minute push-ups, and Standardized 2-minute sit-ups), and Leadership Development Assessment Course field physical fitness scores for male (n = 657) and female (n = 178) Reserve Officers\u27 Training Corps (ROTC) cadets from a southwestern ROTC brigade. An independent sample t-test (PRESULTS: No statistically significant differences were identified between APFT or field physical fitness scores of male and female cadets: Raw 2-minute push-up t(833 ) =.467, .64; Raw 2-minute sit-up t(833) =.719, .47; Raw 2-mile run t(833) t(833) =-.418, t(833) =.952, .34; Standardized 2-mile run t(833) =-.254, .80; overall APFT t(833) =-.132, .90; and field physical fitness t(833) =-.289, .77. CONCLUSION: Brownson (2014) suggested that sex differences should not interfere with physical fitness or physical occupational performance, and based upon qualitative reports female militants possess adequate, and sometimes superior, leadership, physical, and job performance in comparison to male counterparts. These results compliment qualitative reports and suggests female ROTC cadets possess occupationally sufficient physical abilities

Correlation Between Volitional and Functional Balance Control in Healthy Young Athletes

In Volume 3, Issue 1 of the JSMAHS you will find Professionals abstracts, as well Under Graduate student research abstracts, case reports, and critically appraised topics. Thank you for viewing this 3rd Annual OATA Special Edition

Physical Fitness Differences between ROTC Ranger Challenge Cadets and Regular ROTC Cadets

Physical fitness has proven its worth for military personal, as a whole, and individually. A high physical fitness level serves as an influencing variable to completion of special military operation initiation trainings (i.e. BUD/S Training). Consequently, militant whom possess a higher level of physical fitness may gain greater occupational advancement opportunities/placement. Pre-commissioned military programs requiring rigorous physical activity participation, superior to typical physical training (PT), may yield optimal physical capacity for cadets seeking special military operations commission, and/or alternative military placement involving physically demand responsibilities. The fitness level of cadets enrolled in military programs requiring elevated PT standards compared to cadets in “regular” pre-commission programs necessitates examination. PURPOSE: The purpose of the current research was to examine the physical fitness levels, according to Army Physical Fitness Test (APFT) results, of the Reserve Officer Training Corps (ROTC) Ranger cadets (n = 15) compared to Regular ROTC cadets (n = 78). METHODS: Cadets participated in a 12 week Ranger ROTC training program (undulated resistance training; speed, agility, and quickness training; and high intensity interval ruck training) or 12 weeks of the “regular” ROTC calisthenics (i.e. push-ups, sit-ups, bodyweight squats, long-distance running). Upon completed of the training protocols, an APFT was conducted to identify physical fitness level of cadets. An independent sample t-test (α \u3c .05) analyze the mean difference between raw scores, standardized scores, and overall APFT scores of Ranger and Regular cadets. RESULTS: Significant differences were recognized between Ranger and Regular cadets for all aspects of the APFT: Raw 2-minute push-up t(91)=4.281, \u3c.001; Raw 2-minute sit-up t(91)=3.842, \u3c.001; Raw 2-mile run t(91)=-3.993, \u3c.001; Standardized 2-minute push-up t(91)=3.369, \u3c.001; Standardized 2-minute sit-up t(91)=3.668, \u3c.001; Standardized 2-mile run t(91)=3.857, \u3c.001; and overall APFT t(91)=4.130, \u3c.001. CONCLUSION: These results illustrate a drastic difference in physical fitness level among cadets and suggest the elevated fitness level of Ranger cadets may serve as an ample foundation to future military placement and operations

Predictors of Success on the Board of Certification Exam

In Volume 4, Issue 1 of the JSMAHS you will find Professional research abstracts, as well as Under Graduate student research abstracts, case reports, and critically appraised topics. Thank you for viewing this 4th Annual OATA Special Edition. This research is sponsored by an OATA Research Gran

Basic Measurements of Division 1 Collegiate Baseball Pitchers to Predict Grip Strength and Spin Rate

Basic measurements such as range of motion (ROM), grip strength (GS), height, and arm length have been associated with the rate that the ball spins. Increased spin rate along with the axis of rotation of a baseball is linked to the movement that a pitch experiences during its delivery. This spin rate gives a batter difficulty when trying to contact the ball. Plainly, the more spin the more likely the chance the batter will miss. PURPOSE: The purpose of this study was to use external range of motion (EROM), GS, height, weight, forearm length, and forearm circumference to predict spin rate. METHODS: Thirteen right-handed division 1 collegiate baseball pitchers (height 183.2cm± 6.9cm, weight 90kg ± 12kg, forearm length 27.5cm ± 1.3cm, forearm circumference 29.8cm ± 2.1cm, EROM 111.3° ± 9.0°, GS 57.3kg ± 8.4kg, spin rate 2057.2rpm ±160.5rpm) were recruited for this study. Height and weight measurements were recorded using a Doran physician\u27s scale. Measurements of the right forearm were taken from the medial epicondyle of the humerus to the styloid process of the ulna. Forearm circumference was taken from the thickest portion of the forearm. External rotation was measured using a goniometer from a lying position. Spin rate was calculated using a Yakkertech which uses visual imaging technology to calculate spin rate and eliminates the gyro spin of the ball. Ipsilateral hand grip strength was assessed using a Delsys handgrip dynamometer at 90-degree elbow flexion with the elbow unsupported and hand in a neutral grip. The participant was given three attempts to exert as much force as possible and the maximum force in kg was recorded. External rotation of the glenohumeral joint was measured using a goniometer from a lying position with the humerus abducted 90 degrees the subjects were instructed to start with their forearm in a vertical position then slowly drop the back of their hand toward the table. RESULTS: Data were assessed using a forward stepwise multiple regression to identify a statistically significant (p\u3c 0.05) prediction model of spin rate using basic measurements described above. Forearm length was the only variable that was a statistically significant predictor and accounted for 41.8% of the variance in predicting spin rate. The resulting prediction equation was as follows: Spin rate= -165.655rpm - (80.945x FL; R2.418; SEE=127.8). CONCLUSION: Increased forearm length allows for the moment arm to produce more torque on the ball thus increasing the spin rate allowing increased movement on the ball

Changes in Body Composition Following In-Season Training in Division I Football Athletes

Strength and conditioning programs for football athletes tend to focus on maintaining gains from off-seasoning training. Due to a significant decrease in time spent in the weight room relative to the amount of work on the field, various morphological adaptations may occur. PURPOSE: The purpose of this study was to examine the changes in body composition following in-season training in Division I (DI) athletes. METHODS: Fifteen DI football athletes (mean ± sd; age, 20 ± 2 years; height, 189.6 ± 11.6 cm; weight, 114.1 ± 19.5 kg) completed two separate visits to the Human Performance Laboratory immediately before and after in-season training. Using the Jackson and Pollock (1978) 7-site skinfold prediction equation for 18-61 yr male athletes, each athlete’s body density could be calculated and then percent body fat estimated using the Siri Equation to further classify the athlete. A Lange Skinfold Caliper was used to assess both preseason and postseason measures. Each individual was instructed to relax and not hold tension while measures were being taken on the right side of their body. Paired samples t-test were used to compare pre and post measures of body composition (i.e. % body fat). RESULTS: The results from a dependent t-test revealed a significant difference between preseason and postseason body fat percentage (15.12 ± 4.89% vs 13.98 ± 4.63%; t14 = 3.167; p \u3c 0.01), as well as a significant difference between weight (250.98 ± 43.09lbs vs 242.05 ± 42.32lbs; t14= 3.77; p\u3c 0.01). Post-hoc effect sizes indicate that between differences were large preseason for changes in body fat (d= 1.39) and weight (d= 9.16). CONCLUSION: A large effect size suggests that there are meaningful differences between the values. The strength and conditioning program that the athletes were a part of has effectiveness that kept muscle size and strength throughout the season while losing excess body fat