Effects of Diverting Activities on Recovery from Repeated Maximum Voluntary Contractions

Previous investigations have demonstrated that diverting activities (e.g., contralateral exercise and pinching one’s fingers together) can minimize the severity of muscle fatigue that occurs during exercise. In addition to their ability to resist fatigue during exercise, diverting activities may help subjects recover between work bouts. The purpose of this study was to examine the effects of mental and physical diverting activities on recovery from fatiguing isometric muscle actions. On three separate occasions, twelve men (mean ± SD age = 22 ± 1 years) and nine women (age = 22 ± 2 years) performed ten repeated, ten-second isometric maximum voluntary contractions (MVCs) of the dominant leg extensors with ten seconds of rest between each attempt (i.e., ten seconds “on,” ten seconds “off”). Following this fatiguing protocol, the subjects performed math problems (mental diverting activity), five, 20-second isometric muscle actions with the non-dominant leg extensors at a force corresponding to 50% MVC (physical diverting activity), or rested quietly (control). Immediately following this intervention period, the subjects performed a final three-second MVC, which assessed how well the leg extensors recovered from the fatiguing protocol (Post-Recovery MVC). These three data collection trials were randomly performed, and separated by at least 48 hours of rest. A two-way (time [Pre-Fatigue MVC, MVC #1-10, Post-Fatigue MVC, Post-Recovery MVC] × intervention [math problems, contralateral, and control]) repeated measures analysis of variance was used to examine the isometric force data. The mean ± SD Post-Recovery MVC values were as follows: mental diverting activities =765 ± 210 N; physical diverting activities = 797 ± 235 N; control = 790 ± 258 N. There was no significant time × intervention interaction (partial eta squared = .072), no main effect for intervention, but there was a main effect for time. The marginal mean pairwise comparisons indicated: Pre-Fatigue MVC \u3e MVC#1 – Post-Fatigue MVC; MVC #4 – Post-Fatigue MVC \u3c Post-Recovery MVC. In contrast to the results from previous studies, our results indicated that performing mental and physical diverting activities did not help the subjects recover from fatigue

Relationship Between One Repetition Maximum Strength and Peak Power Output for the Free-Weight Bench Press Exercise

Strength and conditioning coaches are often interested in improving power output in their athletes. As many coaches are aware that power is the product of force and velocity, an emphasis is often placed on training with loads that correspond to peak mechanical power output (e.g., 30-50% of the one repetition maximum [1RM]). The purpose of this study was to examine the relationship between 1RM strength and peak power output during the free-weight bench press exercise. Twenty-one healthy, recreationally resistance-trained men (mean ± SD age = 24 ± 3 years; body mass = 90.5 ± 14.6 kg; 1RM bench press = 125.4 ± 18.4 kg) volunteered for this investigation. A minimum of 48 hours following a maximal strength testing and familiarization session, the subjects performed a single repetition of the bench press using 50% of the 1RM. For each repetition, the subjects were instructed press the weight explosively throughout the concentric portion of the range of motion. A Tendo Weightlifting Analyzer was used to assess peak power output for each repetition. A linear regression analysis was used to examine the relationship between 1RM strength and peak power output. The results indicated that the coefficient of determination (R2) was 0.697, suggesting that 1RM strength explained roughly 70% of the variance in peak power output. The linear slope coefficient was 5.94 W/kg, and the y-intercept was 110.2 W. These findings demonstrated that 1RM strength and peak power output were highly correlated. Although explosive training with light loads is often stressed in strength and conditioning programs, for the free-weight bench press exercise, a relatively small degree of variance in peak power output can be explained by factors other than 1RM strength

Creatine Kinase, Lactate Dehydrogenase, and Myoglobin Responses Following Repeated Wingate Anaerobic Tests Versus Barbell Back Squats: a Pilot Study

The results from many previous studies have demonstrated that muscle damage and delayed onset muscle soreness are due primarily to high force, eccentric muscle actions. However, the majority of investigators have examined these responses following single-joint, isokinetic assessments. The purpose of this study was to examine creatine kinase (CK), lactate dehydrogenase (LDH), and myoglobin responses following repeated Wingate anaerobic tests versus multiple sets of the barbell back squat exercise. Six recreationally resistance-trained men (mean ± SD age = 23 ± 2 years, body mass = 88.0 ± 17.8 kg, one repetition-maximum [1RM] back squat = 150.0 ± 28.3 kg) volunteered for this investigation, and visited the laboratory on five separate occasions. For the back squat protocol, the subjects performed six sets until volitional exhaustion using 75% of the 1RM with two minutes of rest between each set. For all repetitions, the subjects squatted to the parallel position. For the Wingate protocol, the subjects performed three tests with a 10 minute recovery period between each attempt. The order of these two protocols was randomized, and all testing for the study occurred at the same time of day. The subjects were required to refrain from vigorous physical activity during the study. Immediately prior to and 24 hours following each protocol, the subjects provided a venous blood sample from a superficial forearm vein. At the conclusion of the study, all samples were processed for CK, LDH, and myoglobin analyses. Three separate two-way (time [Pre versus Post] × protocol [squats versus Wingate anaerobic tests]) repeated measures analyses of variance were used to examine the CK, LDH, and myoglobin data. For CK, there was a significant time × protocol interaction (partial eta squared = .761). Follow-up paired samples t-tests indicated that the mean CK values increased following the squat protocol (Pre mean ± SD = 233.2 ± 97.4; Post = 457.0 ± 119.9 IU/L), but not the Wingate anaerobic tests (Pre = 218.5 ± 103.9; Post = 231.7 ± 65.3 IU/L). There was no mean difference between the protocols for both LDH and myoglobin. The primary finding from this pilot study was that performing six sets of barbell back squats using 75% of the 1RM significantly increased blood CK levels in resistance-trained men. Although additional studies with larger sample sizes are needed to confirm our findings, CK appears to be a more sensitive measure of muscle damage than both LDH and myoglobin

Linear Progression for Increased External Loads during Strength Training

Improvements in muscular strength require an individual to train with progressively increased external loads over time. While it is well documented that the initial adaptations to strength training occur rapidly, previous researchers have not thoroughly examined the most effective means of inducing these changes. The purpose of this study was to examine the ability to add 2.27 kg to the barbell for 20 consecutive training sessions, and to compare these responses between the sexes. Thirty-four subjects ([mean ± SD age = 23 ± 3 years] men, n = 17; women, n = 17) participated in this study. The subjects were taught how to perform the barbell deadlift exercise, and received individual instruction and verbal feedback regarding their technique throughout the entire investigation. The subjects visited the laboratory twice per week for ten weeks. The external loads corresponded to the maximum weight that each subject could use to perform five sets of five repetitions with correct technique. If five sets of five repetitions were performed, 2.27 kg were added to the barbell for the following training session. The mean external load for each training session was recorded. The data were analyzed with bivariate regression and repeated measures analyses of variance (ANOVAs). The mean ± SD external loads used in this study increased from 66.2 ± 22.3 to 123.1 ± 21.8 kg for the men and 37.8 ± 7.0 to 70.7 ± 12.2 for the women. The results from the repeated measures ANOVAs indicated that men were able to add 2.27 kg to the barbell for 17 consecutive training sessions. For the women, however, the progress stalled at roughly week six. As a result, the coefficient of determination for the external load versus training session number relationship was r2 = .960 for the men and r2 = .881 for the women. These findings demonstrated that adding 2.27 kg to the barbell for each training session was an effective method for progressively increasing the external load over a ten week period. Many of the women had a difficult time with this gradual increase after week six, however, suggesting that smaller absolute changes with fractional plates (e.g., 0.91 kg) may be necessary

Effects of a Ten Week Barbell Deadlift Training Program on Vertical Jump Height in College-Aged Women

The barbell deadlift is a large muscle mass exercise that primarily involves extension at the hip and knee joints. Although it is often incorporated into strength training programs with a variety of other exercises (e.g., back squat), no previous studies have examined the effects of deadlift training on strength or power adaptations. The purpose of this investigation was to examine the effects of a ten week barbell deadlift training program on vertical jump height in previously untrained women. Twenty-eight women (mean ± SD age = 22 ± 2 years) were randomly assigned to either the training group (n = 17) or the control group (n = 11). The training group visited the laboratory for supervised exercise twice per week for ten weeks. Each training session involved five sets of the barbell deadlift, and each set utilized the heaviest external load that allowed for five repetitions with proper exercise technique. If all repetitions were performed with correct technique, additional weight (≤ 2.27 kg) was added to the barbell during the next training session. The control group was asked to refrain from lower-body exercise throughout the course of the study. Vertical jump height was assessed with a Vertec before and after the ten week intervention. An analysis of covariance (ANCOVA) was used to examine the data, and the pretest and posttest values were used as the covariate and dependent variable, respectively. The ANCOVA indicated that the posttest mean for the training group (42.5 cm) was significantly greater than that for the control group (39.0 cm) after adjusting for the pretest vertical jump height scores (p = .012, η² = .229). The effect size for the unadjusted mean increase for the training group (3.6 cm) was considered small-to-moderate (Cohen’s d = .37). These findings demonstrated that a ten week exercise training program using only the barbell deadlift significantly improved vertical jump height in college-aged women

Measuring attitude toward theistic faith : assessing the Astley-Francis Scale among Christian, Muslim and secular youth in England

Empirical research within the social scientific study of religion in general and within the psychology of religion in particular remains very conscious of the complex nature of its subject matter. Empirical research in this field needs to take cognisance of the many forms in which religion is expressed (say, Buddhism, Christianity, Hinduism, Islam, Judaism, and Sikhism) and the many facets within the forms (say, beliefs, behaviours and affiliation). Working in the 1970s, Francis (1978a; 1978b) advanced the view that the attitudinal dimension of religion offered a particularly fruitful basis for coordinating empirical enquiry into the correlates, antecedents and consequences of religiosity across the life span

The Williams Scale of Attitude toward Paganism: development and application among British Pagans

This article builds on the tradition of attitudinal measures of religiosity established by Leslie Francis and colleagues with the Francis Scale of Attitude toward Christianity (and reflected in the Sahin-Francis Scale of Attitude toward Islam, the Katz-Francis Scale of Attitude toward Judaism, and the Santosh-Francis Scale of Attitude toward Hinduism) by introducing a new measure to assess the attitudinal disposition of Pagans. A battery of items was completed by 75 members of a Pagan Summer Camp. These items were reduced to produce a 21-item scale that measured aspects of Paganism concerned with: the God/Goddess, worshipping, prayer, and coven. The scale recorded an alpha coefficient of 0.93. Construct validity of the Williams Scale of Attitude toward Paganism was demonstrated by the clear association with measures of participation in private rituals

Barbell deadlift training increases the rate of torque development and vertical jump performance in novices

The primary purpose of this study was to examine the effects of 10 weeks of barbell deadlift training on rapid torque characteristics of the knee extensors and flexors. A secondary aim was to analyze the relationships between training-induced changes in rapid torque and vertical jump performance. Fiftyfour subjects (age, mean 6 SD = 23 6 3 years) were randomly assigned to a control (n = 20) or training group (n = 34). Subjects in the training group performed supervised deadlift training twice per week for 10 weeks. All subjects performed isometric strength testing of the knee extensors and flexors and vertical jumps before and after the intervention. Torque-time curves were used to calculate rate of torque development (RTD) values at peak and at 50 and 200 milliseconds from torque onset. Barbell deadlift training induced significant pre- to post-increases of 18.8–49.0% for all rapid torque variables (p , 0.01). Vertical jump height increased from 46.0 6 11.3 to 49.4 6 11.3 cm (7.4%; p , 0.01), and these changes were positively correlated with improvements in RTD for the knee flexors (r = 0.30–0.37, p , 0.01–0.03). These findings showed that a 10-week barbell deadlift training program was effective at enhancing rapid torque capacities in both the knee extensors and flexors. Changes in rapid torque were associated with improvements in vertical jump height, suggesting a transfer of adaptations from deadlift training to an explosive, performancebased task. Professionals may use these findings when attempting to design effective, time-efficient resistance training programs to improve explosive strength capacities in novices

Barbell deadlift training increases the rate of torque development and vertical jump performance in novices

The primary purpose of this study was to examine the effects of 10 weeks of barbell deadlift training on rapid torque characteristics of the knee extensors and flexors. A secondary aim was to analyze the relationships between training-induced changes in rapid torque and vertical jump performance. Fiftyfour subjects (age, mean 6 SD = 23 6 3 years) were randomly assigned to a control (n = 20) or training group (n = 34). Subjects in the training group performed supervised deadlift training twice per week for 10 weeks. All subjects performed isometric strength testing of the knee extensors and flexors and vertical jumps before and after the intervention. Torque-time curves were used to calculate rate of torque development (RTD) values at peak and at 50 and 200 milliseconds from torque onset. Barbell deadlift training induced significant pre- to post-increases of 18.8–49.0% for all rapid torque variables (p , 0.01). Vertical jump height increased from 46.0 6 11.3 to 49.4 6 11.3 cm (7.4%; p , 0.01), and these changes were positively correlated with improvements in RTD for the knee flexors (r = 0.30–0.37, p , 0.01–0.03). These findings showed that a 10-week barbell deadlift training program was effective at enhancing rapid torque capacities in both the knee extensors and flexors. Changes in rapid torque were associated with improvements in vertical jump height, suggesting a transfer of adaptations from deadlift training to an explosive, performancebased task. Professionals may use these findings when attempting to design effective, time-efficient resistance training programs to improve explosive strength capacities in novices