Dana K. Fuller

THE EFFECT OF STATIC STRETCHING ON PHASES OF SPRINT PERFORMANCE IN ELITE SOCCER PLAYERS

Sayers, AL, Farley, RS, Fuller, DK, Jubenville, CB, and Caputo, JL. The effect of static stretching on phases of sprint performance in elite soccer players. J Strength Cond Res 22(5): 1416-1421, 2008-The purpose of this study was to determine which phase of a 30-m sprint (acceleration and/or maximal velocity) was affected by preperformance static stretching. Data were collected from 20 elite female soccer players. On two nonconsecutive days, participants were randomly assigned to either the stretch or no-stretch condition. On the first day, the athletes in the no-stretch condition completed a standard warm-up protocol and then performed three 30-m sprints, with a 2-minute rest between each sprint. The athletes in the stretch condition performed the standard warm-up protocol, completed a stretching routine of the hamstrings, quadriceps, and calf muscles, and then immediately performed three 30-m sprints, also with a 2-minute rest between each sprint. On the second day, the groups were reversed, and identical procedures were followed. One-way repeated-measures analyses of variance revealed a statistically significant difference in acceleration (p < 0.0167), maximal-velocity sprint time (p < 0.0167), and overall sprint time (p < 0.0167) between the stretch and no-stretch conditions. Static stretching before sprinting resulted in slower times in all three performance variables. These findings provide evidence that static stretching exerts a negative effect on sprint performance and should not be included as part of the preparation routine for physical activity that requires sprinting.

Physical Activity and Quality of Life in Adults With Spinal Cord Injury

Abstract Background/Objective: To document the relationship between level of physical activity and quality of life in persons with spinal cord injury. Design: Cross-sectional investigation. Participants/Methods: Men (n = 32) and women (n = 30) with complete and incomplete spinal cord lesions below C6 volunteered to participate in this study. The average length of time since the onset of disability was 9 years (range, 1.5-40 years). Using an interview-formatted survey (Quality of Well-Being Scale), a measure of quality of life was obtained for each participant. Physical activity levels were determined using the Physical Activity Scale for Individuals with Physical Disabilities. Results: A strong positive association (r= 0.75; P < 0.05) was observed between level of physical activity and quality of life. Multiple regression analysis also showed that when level of physical activity, anatomical location of the injury, completeness of injury, and time since injury were used as explanatory variables, level of physical activity was the only significant predictor of quality of life, accounting for 56% of the total variation in quality of life. Conclusions: Results from this study show that a significant and moderately strong positive relationship exists between level of physical activity and quality of life in adults with spinal cord injury. From a clinical perspective, these findings suggest that interventions aimed at promoting physical activity may be effective in improving quality of life in this population.

Influence of age on step activity patterns in children with cerebral palsy and typically developing children.

OBJECTIVE To document the influence of age on step activity patterns in children with cerebral palsy (CP) and typically developing (TD) children. DESIGN Cross-sectional. SETTING All step activity data were collected in free-living environments. PARTICIPANTS Children with CP (n=27; age, 4-18y; 22 boys, 5 girls; Gross Motor Function Classification System levels I and II) and 27 age- and sex-matched TD children were recruited through public advertisements and contacts with local clinicians. CP and TD participants were stratified into younger (<10y; n=14) and older (10-18y; n=13) age groups. INTERVENTION Daily step activity was monitored using a step activity monitor that was individually programmed to account for the gait characteristics of each participant. Step activity data were collected in 1-minute epochs during waking hours on 3 weekdays and 1 weekend day. Stored data were analyzed to yield average values of daily step activity, percentage of inactive time (0 steps) over the entire day, and percentage of total daily active time spent in low step activity (1-15 steps/min), medium step activity (16-40 steps/min), and high step activity (>40 steps/min). MAIN OUTCOME MEASURES Daily step activity, percentage of inactive time, and percentage of active time spent in low-, moderate-, and high-intensity step activity. RESULTS A significant (P<.05) interaction was observed between age (younger, older) and condition (CP, TD) for daily step activity, percentage of inactive time, and percentage of active time spent in low- and high-intensity step activity. The main effect of age was significant for each physical activity measure except for relative high-intensity step activity, and the main effect of condition was significant for all physical activity measures. Follow-up analyses (P<.025) revealed that older children with CP took fewer daily steps and displayed higher relative levels of inactivity and low-intensity activity and lower relative levels of high-intensity activity compared with older TD children. Older children with CP also exhibited lower daily step activity, demonstrated higher relative levels of inactivity and low-intensity activity, and displayed lower relative levels of moderate-intensity activity compared with younger children with CP. CONCLUSIONS Compared with younger children with CP and age- and sex-matched TD youth, older youth with CP generally displayed step activity patterns typified by lower levels of physical activity and a greater degree of inactivity. These findings highlight the need to provide multiple opportunities for adolescents with CP to engage in a variety of physical activities that are appropriate to their needs, abilities, and preferences and that can aid in maintaining functional mobility, health, and quality of life.

Validation of the SenseWear Armband as a Measure of Sedentary Behavior and Light Activity.

BACKGROUND This study determined the validity and sensitivity of the SenseWear armband (SWA) during sedentary and light office duties compared with indirect calorimetry (IC). METHODS Participants (N = 22), 30 to 64 years of age, randomly performed 6 conditions for 5 minutes each (ie, supine, sitting no movement, standing no movement, sitting office work, standing office work, walking at 1.0 mph). Steady state for each activity (ie, average for minutes 4 and 5) was analyzed. RESULTS Energy expenditure (EE) for the SWA (1.58 kcal/min) and the IC (1.64 kcal/min) were significantly correlated, r(20) = 0.90, P < .001 and ICC = 0.90, 95% CI (0.699, 0.966). Correlation results for each condition varied in strength, r(20) = 0.53 to 0.83 and ICC = 0.49 to 0.81, but were all significant (P < .05). A significant interaction between measurement method and condition existed (P < .001). The SWA under predicted EE during standing with no movement, sitting office work, and standing office work. CONCLUSION The SWA and IC EE rates were strongly correlated during sedentary and light activity office behaviors. However, the SWA may under predict EE during office work (standing or sitting) and when standing motionless, making it slightly less sensitive than IC.

Psychological Predictors of Mental Toughness in Elite Tennis: An Exploratory Study in Learned Resourcefulness and Competitive Trait Anxiety:

The purpose of this study was to examine the extent to which two constructs, learned resourcefulness and competitive trait anxiety, measured by the Self-Control Schedule and Sports Competition Anxiety Test, respectively, predicted mental toughness on the Sports Mental Toughness Questionnaire among male and female elite tennis players. The participants included two NCAA Division 1 (U.S.) intercollegiate tennis teams comprising eight male (M age = 19.4 yr., SD = 1.2) and eight female (M age = 20.9 yr., SD = 1.4) players and their respective head coaches (N = 2, M age = 28 yr., SD = 5.7). Results of regression analyses indicated that learned resourcefulness was the primary predictor of athlete self-rated mental toughness and that competitive trait anxiety was relatively unrelated to coach and athlete-rated mental toughness. The positive significant relationship between mental toughness and learned resourcefulness suggests that the latter may be an integral component of mental toughness, at least among elite tennis players. Further research is needed to examine related components of mental toughness, including learned resourcefulness, and to determine the effectiveness of interventions that increase mental toughness to optimal levels, particularly as a function of sport type.

Leg Strength, Preferred Walking Speed, and Daily Step Activity in Adults With Incomplete Spinal Cord Injuries

BACKGROUND The reduction in physical activity that accompanies spinal cord injury (SCI) contributes to the development of secondary health concerns. Research has explored potential strategies to enhance the recovery of walking and lessen the impact of physical disability following SCI, but further work is needed to identify determinants of community walking activity in this population. OBJECTIVES To quantify relationships among lower extremity strength (LES), preferred walking speed (PWS), and daily step activity (DSA) in adults with incomplete SCI (iSCI) and determine the extent to which LES and PWS predict DSA in persons with iSCI. METHODS Participants were 21 adults (age range, 21 to 62 years; AIS levels C and D) with iSCI. Maximal values of hip abduction, flexion, and extension, knee flexion and extension, and ankle dorsiflexion and plantar flexion were measured using handheld dynamometry and were summed to determine LES. PWS was calculated using a photoelectric cell-based timing system, and participants were fitted with activity monitors to measure DSA in a natural setting. RESULTS Statistically significant (P <; .05) correlations of moderate to high magnitude (.74 to .87) were observed among LES, PWS, and DSA. Multiple regression analysis revealed that LES and PWS accounted for 83% (adjusted R2) of the variation in DSA (P <; .001). CONCLUSION A significant proportion of the explained variance in DSA can be predicted from knowledge of LES and PWS in adults with iSCI. These findings suggest that future efforts to improve community walking behavior following SCI should be directed toward increasing LES and PWS.

The Relationship between Cortisol and Bone Mineral Density in Competitive Male Cyclists

Objective. The purpose of this study was to determine whether race day cortisol was related to bone mineral density (BMD) in competitive male cyclists. A secondary purpose was to determine additional factors associated with BMD in competitive male cyclists. Methods. Measurements of lumbar spine and hip BMD were performed in 35 male competitors in a state championship cycling time trial event. Salivary cortisol was measured 10 minutes prior to the start of the race and 5 minutes after race finished. Participants reported daily calcium intake, age, years of bike training, races per season, and average weekly minutes spent riding a bike, weight training, and running on a survey. Results. Cortisol level increased significantly from pre- to postcompetition but was not significantly associated with BMD. Increased weekly minutes of weight training was associated with higher BMD of the lumbar spine and the hip. The increased number of years of cycling experience was associated with lower BMD of the femoral neck. Increased daily calcium intake was associated with higher BMD of the lumbar spine and femoral neck. Conclusions. Findings indicate that cyclists should participate in weight training and increase calcium intake in order to increase or maintain BMD of the lumbar spine and hip.

Choice of information to discuss: Effects of objective validity and social validity.

Members of 43 three-person groups completed a deductive logic task. Each member was provided with unique clues and information indicating the utility of each clue. Objective validity varied because some clues were essential to problem solution and others were not useful. Social validity was manipulated by informing participants that some clues would likely be useful and that other clues were not likely to be useful. Clues were discussed more frequently if either objective validity or social validity was high, but the effects were not additive. Clues were discussed less frequently in the low objective validity–low social validity condition than in all other conditions. Alignment of both types of validity facilitated the group’s ability to focus on relevant information.

Superior Self-Regulatory Skills in African American College Students Evidence From Alcohol and Tobacco Use

Excessive drinking is more common among Whites (W) than African Americans (AA) on college campuses, but the reasons for this are not clear. The authors investigated demographic and personality factors in a group of 369 W and 202 AA college students, finding that alcohol consumption was significantly less prevalent among AA students (69%) than W students (78%) (p = .02) and that binge drinking was significantly less frequent in AA drinkers (42% past month, 60% past year) than W drinkers (56%, 79%) (p < .00001). Cigarette smoking was also dramatically less frequent in AA students (5%) than W students (28%) (p < .00001). AA students also scored significantly higher on Overcontrolled Hostility (M = 18.2, SEM = 0.40) than did W students (M = 15.7, SEM = 0.19) (p < .00001). The authors conclude that AA college students are a more self-selected group of high achievers who reveal evidence of superior self-regulatory skills.

Strength and Step Activity After Eccentric Resistance Training in Those With Incomplete Spinal Cord Injuries

Background: Individuals with spinal cord injuries (SCIs) often experience general weakness in the lower extremities that undermines daily step activity. Objective: To investigate the efficacy of eccentrically biased resistance training on lower extremity strength and physical activity of individuals with spinal injuries. Methods: Individuals with long-standing incomplete SCIs (N = 11) capable of completing a 10-meter walk assessment were included. All participants who completed the familiarization period finished the training. Individuals trained two times per week for 12 weeks on a lower body eccentric resistance training machine. It was hypothesized that the outcome variables (eccentric strength, isometric strength, and daily step physical activity) would improve as a result of the training intervention. Results: Eccentric strength [F(1.27, 12.71) = 8.42, MSE = 1738.35, H-F p = .009] and isometric strength [F(1.97, 19.77) = 7.10, MSE = 11.29, H-F p = .005] improved as a result of the training while daily step activity remained unchanged [F(2.00, 18.00) = 2.73, MSE = 216,836.78, H-F p = .092]. Conclusions: Eccentric resistance training improves eccentric and isometric strength. These physiological adaptations may translate to improved gait mechanics, but further study is required to identify this potential crossover effect.