American Journal of Sports Science and Medicine

This study examined the effects of power-based complex training (PCT) on body composition and muscular strength in male and female collegiate athletes. Twenty one athletes (12 female soccer players and 9 male football players) participated in a supervised PCT program for 6 weeks, which consisted of a variety of Olympic-style and traditional weightlifting movements and plyometrics. Following the 6-week PCT program, males did not significantly alter body composition, whereas females positively altered body composition without a significant change in body weight by increasing muscle mass (+1.32 kg, p = 0.044) and decreasing fat mass (-1.90 kg, p = 0.005) and % body fat (-2.60%, p = 0.006). The 6-week PCT program significantly increased upper and lower body strength in both males and females: 1) clean [males: +10.47%, p = 0.001 and females: +19.98%, p = 0.001], 2) incline press [males: +8.81%, p = 0.021 and females: 8.93%, p = 0.002], and 3) squat [males: +13.17%, p = 0.002 and females: +17.44%, p = 0.001]. A post-training percent change in clean for females was significantly greater than males (19.98 vs. 10.47%, p = 0.001), while the other post-training percent changes were not different. The current study suggests that the 6-week PCT program can positively alter body composition particularly for female athletes and significantly improve upper and lower body strength for both male and female athletes, which will contribute to improvement in athletic performance.

American Journal of Sports Science and Medicine. 2014, 2(5), 202-207. DOI: 10.12691/ajssm-2-5-5
Pub. Date: November 12, 2014

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Lance Armstrong’s Era of Performance — Part II: Revisiting His Time Trial Wins

by Hein F.M. Lodewijkx and Arjan E.R. Bos

Original Research

This archival study (N = 100) compared Lance Armstrong’s time trial wins to victories demonstrated by all former multiple Grand Tour winners (1949–1995; Coppi, Anquetil, Merckx, Hinault, Indurain) and by riders who won similar races in the three major European Grand Tours (Tour de France, Giro d’Italia, and Vuelta a España) from 2006 to 2013, who were either involved in doping affairs or not. Regression analyses yielded a non–significant M = 142 seconds difference between Armstrong vs. the aggregated other riders (ΔR² = .001, p = .20). The effect emerged after controlling for the influence of competition year (b = -12.23 s per year, ΔR2 = .045, p ≤ .001) and trial distances (b = 84.64 s per kilometer trial distance, ΔR² = .933, p ≤ .001) on the variation in riders’ speed. Furthermore, Armstrong along with other riders who were suspended for doping use or who acknowledged having used doping in the 2006–2013 periods did not outperform riders who were not involved in doping affairs during the same years (M = -68 s, ΔR² = .01, p = .35). Findings disprove the argument from ignorance, a false logic which refers to the often heard opinion that cyclists’ performances over time (including Armstrong’s wins) are mainly determined by their use of increasingly potent doping aids. However, in contrast to this logic, the distances of the time trials constitute the main determinant of riders’ performances rather than the year in which they competed, and riders engaged in doping affairs did not significantly outperform riders who were not.

American Journal of Sports Science and Medicine. 2014, 2(5), 194-201. DOI: 10.12691/ajssm-2-5-4
Pub. Date: November 10, 2014

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Accuracy of Force Exertion in Response to Demanded Forces Based on Subjective Information and Laterality

by Takanori Noguchi, Shinichi Demura and Masashi Omoya

Original Research

The strength required for motor activities should be exerted effectively according to the type of activity and the load size. This study examined the relationship between the accuracy of handgrip exertion for demanded forces of 20%–80% of the maximal voluntary contraction (MVC) and laterality. Subjects were 100 healthy young males (mean age, 22.4 ± 2.8 years). After the handgrip MVC was measured, subjects attempted to exert a handgrip at demanded forces of 20, 40, 60, and 80% of the MVC. All tests were performed twice and with dominant and non-dominant hands, and mean values were used for statistical analysis. Differences between demanded forces and exerted forces were converted into relative values based on each subject’s MVC. Two-way repeated measures ANOVA showed significant interaction between demanded forces and laterality. In multiple comparison tests, smaller demanded forces were associated with larger errors only in the non-dominant hand. For demanded forces of 20% and 40% MVC errors were smaller for the dominant hand than for the non-dominant hand. The non-dominant hand is used less than the dominant hand in daily life and in sport activities. It is therefore not unexpected that a laterality-based difference in the accuracy of exerted force for each demanded force is found, and the accuracy of exerted force at low demanded forces was inferior for the non-dominant hand. In conclusion, there was a difference in the accuracy of exerted force for each demanded force for the non-dominant hand with a larger error at lower demanded forces. In particular, the accuracy of exerted force in response to demanded forces of 40% MVC or less was inferior in the non-dominant hand compared with that in the dominant hand. Laterality is therefore a significant factor in force response to lower demanded force values.

American Journal of Sports Science and Medicine. 2014, 2(5), 190-193. DOI: 10.12691/ajssm-2-5-3
Pub. Date: November 06, 2014

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A Review of the Scientific Evidence for Acupuncture and Dry Needling Compared in Common Sporting Conditions and Medical Disorders

by Alex Huntly and Daniel Berdejo-del-Fresno

Review Article

There is an evidence base of varying strength for the use of acupuncture in conditions, such as chronic low back pain, myofascial trigger point, osteoarthritis, pain relief, performance enhancement and respiratory disorders. The aim of this study was to review the evidence base of acupuncture for common conditions that occur in sport. A literature review of how acupuncture works and what it can treat was performed. Evidence for each condition was critically appraised. There are significant differences in the perceived effectiveness of acupuncture for different conditions and mechanisms. Chronic low back pain, myofascial trigger point, acute low back pain and osteoarthritis were perceived to be effective. All of the reviewed mechanisms of acupuncture were perceived more effective than Chinese meridian. Those conditions that were rated as less effective generally had less supporting evidence or were not relevant to sporting populations.

American Journal of Sports Science and Medicine. 2014, 2(5), 181-189. DOI: 10.12691/ajssm-2-5-2
Pub. Date: October 27, 2014

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Are the Children´s Predispositions for Physical Exercise Influenced by Their Body Mass?

by Václav Bunc and Marie Skalská

Original Research

Poor nutrition, in addition to an overall lack of exercise, is one of the major issues of the current lifestyle. The most common consequence is the increase in overweight and obesity and decrease of physical fitness. The basic questions needed to be answered when designing exercise intervention: Are the physical assumptions affected by overweight or obese state? The exercise predispositions can be evaluated by the extracellular (ECM) and intracellular (BCM) mass ratio. To verify the dependence of the ECM/BCM on body mass (BM) we calculated ECM/BCM for girls (normal BM, N=1598, mean age=12.8±3.6yrs, BMI=19.5±0.2 kg.m^-2; overweight, 178, 12.6±3.2, 24.7±0.4; obese, 219, 12.9±3.4, 29.6±0.6), and in boys (normal BM, N=1810, mean age=12.9±3.9yrs, BMI=19.9±0.3 kg.m^-2; overweight, 253, 1286±3.2, 24.9±0.4; obese, 242, 12.9±3.4, 30.3±0.6) differing in BM. We did not find significant differences in the ECM/BCM in girls and the same in boys, and non-significant dependence on BM. In conclusion: 1. the morphological predispositions for exercise are not dependent on BM, 2. do not exist any objective limitations for regular exercise realized in the children, 3. for successful management of an overweight and/or obesity, it is necessary to influence both the diet and exercise.

American Journal of Sports Science and Medicine. 2014, 2(5), 177-180. DOI: 10.12691/ajssm-2-5-1
Pub. Date: September 25, 2014

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