The reliable examination of isokinetic parameters in young athletes is important for the establishment of appropriate strength testing protocols. The purpose of this study was to examine the reliability of peak moments, non-preferred/preferred leg and reciprocal ratios during isokinetic knee efforts in young soccer players. Thirteen circumpubertal (age = 13.0 ± 0.4 years) soccer players performed maximum knee extension and flexion efforts at 30, 120 and 180°·s1 in two occasions, a week apart. The reliability of the peak moments was high, with reliability coefficients ranging from 0.71 to 0.98. The non-preferred/preferred leg and reciprocal ratios demonstrated moderate to high reliability (coefficients ranged from 0.42 to 0.87). The reliable examination of moments of force and ratio measurements during eccentric tests and at fast angular velocities in young soccer players requires extensive familiarization of the subjects prior to the main test.
Eleftherios Kellis, Spiros Kellis, Vasilios Gerodimos and Vasiliki Manou
Myriam Guerra Balic, Eufemia Cuadrado Mateos, Carolina Geronimo Blasco and Bo Fernhall
The purpose was to compare physical fitness of two groups of adults with Down syndrome, one active group of Special Olympians (9 males, 4 females), and one sedentary group (5 males, and 2 females). The active group had trained for an average of 4.9 hr per week for a minimum of 1 year for Special Olympics competitions. Participants underwent laboratory testing, including (a) treadmill test to determine peak oxygen uptake; (b) isometric strength tests of handgrip, lower back, and quadriceps; (c) explosive power; and (d) body composition. Peak oxygen consumption and muscle strength were significantly greater in the active group. Although crossectional, these findings suggest that long term exercise training, at a greater than previously reported weekly training load, may enhance physical fitness in individuals with Down syndrome.
Dennis Dreiskaemper, Bernd Strauss, Norbert Hagemann and Dirk Büsch
Hill and Barton (2005) showed that fighters in tae kwon do, boxing, and wrestling who wore red jerseys during the 2004 Olympic Games won more often than those wearing blue jerseys. Regarding these results, this study investigated the effects of jersey color during a combat situation on fighters’ physical parameters of strength and heart rate. An artificial, experimental combat situation was created in which the color of sport attire was assigned randomly. Fourteen pairs of male athletes matched for weight, height, and age had to fight each other: once in a red jersey and once in a blue. Heart rate (before, during, and after the fight) and strength (before the fight) were tested wearing the blue and the red jerseys. Participants wearing red jerseys had significantly higher heart rates and significantly higher pre-contest values on the strength test. Results showed that participants’ body functions are influenced by wearing red equipment.
Russell R. Pate, Stewart G. Trost, Marsha Dowda, Alise E. Ott, Dianne S. Ward, Ruth Saunders and Gwen Felton
This study examined the tracking of selected measures of physical activity, inactivity, and fitness in a cohort of rural youth. Students (N = 181, 54.7% female, 63.5% African American) completed test batteries during their fifth- (age = 10.7 ± 0.7 years), sixth-, and seventh-grade years. The Previous Day Physical Activity Recall (PDPAR) was used to assess 30-min blocks of vigorous physical activity (VPA), moderate-to-vigorous physical activity (MVPA), TV watching and other sedentary activities, and estimated energy expenditure (EE). Fitness measures included the PWC 170 cycle ergometer test, strength tests, tnceps skinfold thickness, and BMI. Intraclass correlation coefficients (ICCs) for VPA, MVPA, and after-school EE ranged from 0.63 to 0.78. ICCs ranged from 0.49 to 0.71 for measures of inactivity and from 0.78 to 0.82 for the fitness measures. These results indicate that measures of physical activity, inactivity, and physical fitness tend to track during the transition from elementary to middle school.
Taina Rantanen and Eino Heikkinen
The aim of this study was to examine alterations in maximal isometric strength of multiple muscle groups over 5 years and to compare strength changes between individuals who maintained a high level of physical activity and others who did not. As a part of the Evergreen Project, 20 men and 59 women participated in at least one strength test at the age of 80 and again 5 years later. Men displayed no decrease in lean body mass over the follow-up. and the only significant strength decrease was in elbow flexion strength. In women, both lean body mass and muscle strength decreased significantly (except trunk extension strength). Overall, those men and women who were considered to have maintained a high level of activity retained their strength at a higher level than the more sedentary participants. Older people should be encouraged to continue physically demanding activities to maintain muscle strength at an adequate level for independent living.
Koen A.P.M. Lemmink, Kemper Han, Mathieu H.G. de Greef, Piet Rispens and Martin Stevens
Several items of the Groningen Fitness Test for the Elderly (GFE) were tested. The GFE tests were administered twice, with 1 week between sessions. The participants were 458 independently living adults >55 years of age. For most tests, there was reasonable agreement between sessions, indicating absolute objectivity and stability, but results on the block-transfer test revealed a learning effect. Mean scores on the balance-board and sit-and-reach tests showed significant improvement, whereas grip-strength results deteriorated significantly. All tests satisfied the criteria for relative reliability. In conclusion, absolute and relative reliability of the tests of the GFE were satisfactory. If multiple applications of the GFE are planned for the same group of participants, 1 or more practice trials should be executed for the block-transfer test to avoid a learning effect. A standard warm-up protocol is recommended for the sit-and-reach test. Participants should be strongly encouraged to give a maximum effort on the strength tests.
Johanne Desrosiers, François Prince, Annie Rochette and Michel Raîche
The objectives of this study were to standardize measurement procedures and study the test-retest and interrater reliability of the belt-resisted method for measuring the lower extremity isometric strength of three muscle groups. The strength of 33 healthy, elderly, community-dwelling subjects was evaluated with a hand-held dynamometer using the belt-resisted method. Isometric strength testing of three muscle groups (hip flexors, knee extensors, and ankle dorsiflexors) was performed on two separate occasions, I week apart, by the same tester to determine test-retest reliability. The test results of two different examiners testing on different days were used to determine interrater reliability. Test-retest reliability was higher than interrater reliability. Test-retest reliability coefficients of the three muscle groups were high (J9-.95). For interrater reliability, intraclass correlation coefficients varied from .64 to .92. depending on the muscle group and side. For the two kinds of reliability, intraclass correlation coefficients increased from proximal to distal. The method for the hip muscle group should be modified to increase reliability of the measure.
Rodrigo Antunes Lima, Lisbeth Runge Larsen, Anna Bugge and Lars Bo Andersen
Purpose: The current investigation aimed to investigate the longitudinal association between physical fitness and academic performance over 3 years in adolescents. A secondary aim was to determine to what extent waist circumference mediated the association between physical fitness and academic performance. Methods: For the current study, 1020 students from first grade [mean age: 7.87 (0.34) y] to fifth grade [mean age: 11.87 (0.37) y] were monitored annually for 3 years (2010–2013). Physical fitness was assessed using the Andersen test, 5 × 5-m shuttle run, jump height, and grip strength tests and by constructing a composite score combining all 4 fitness tests. Academic performance was assessed by national standardized tests in Danish language and math. Generalized structural equation modeling was used to evaluate the relationships between these variables. Results: The Andersen test (standardized β = 0.15 SD), shuttle run (β = −0.18 SD), jump height (β = 0.10 SD), and the fitness composite score (β = 0.23 SD) were positively associated with academic performance over 3 years. In addition, waist circumference partially mediated the association between physical fitness and academic performance. Conclusion: Thus, physical fitness abilities should be stimulated during childhood and early adolescence because of their positive association with academic performance.
Andrew C. Fry, Carol C. Irwin, Justin X. Nicoll and David E. Ferebee
To determine absolute and relative (adjusted for body mass) strength, mean power, and mean velocity for upper and lower body resistance exercises, forty-seven young boys and girls participated in maximal strength testing. Healthy young boys and girls, ages 3- to 7-years old, were tested for one-repetition maximum (1-RM) strength, and 70% of 1-RM to determine mean power and mean velocity on the chest press and leg press exercises. Adult weight machines were modified to accommodate the smaller size and lower strength levels of the children. A 2 × 4 (sex × age) ANOVA was used to determine age and sex differences in performance. No interaction or sex differences were observed for any variable at any age. 1-RM strength, mean power, and mean velocity significantly increased across ages (p ≤ .05). When adjusted for body mass, the changes were insignificant, with one exception. Relative mean power for the bench press increased with age. Data indicated children from 3-7 years of age are capable of performing strength and power tests, but may require more attempts at maximal loads compared with adults. It appears that muscular strength and velocity during this stage of development are primarily dependent on increasing body mass, whereas power is influenced by additional variable(s).
Joe Nocera, Mack Rubley, William Holcomb and Mark Guadagnoli
There is limited information on the effects of throwing on shoulder proprioception and strength.
Examine shoulder proprioception and strength following throwing.
2x3 mixed-subject design.
Research laboratory and outdoor facility.
23 male college students (age = 22 ± 2.9yr, ht = 178 ± 11.3cm, wt = 72 ± 7.7kg, 22 right-handed 1 left-handed).
Subjects were pretested for proprioception, measured by active reproduction of passive positioning (ARPP). Strength was quantified using 1RM and an average peak torque at 120º/sec for internal and external shoulder rotation. Following pretesting, subjects (excluding control) completed 75 throws at 75% maximum immediately followed by posttesting.
Main Outcome Measures:
Pre and post ARPP absolute error and strength changes.
Significant difference in the pre and posttest ARPP values for throwing groups but no difference for the control group. There was no significant difference from pre to post on the strength tests for any groups.
Results indicate that repetitive throwing affects proprioception while not affecting strength.