The effects of repetitive loading on bone mass and geometry in young male tennis players : a quantative study using magnetic resonance imaging

Pre- and early puberty seem to be the most opportune times for exercise to  improve bone strength in girls, but few studies have addressed this issue in boys. This study investigated the site-, surface-, and maturity-specific exercise-induced changes in bone mass and geometry in young boys. The osteogenic effects of loading were analyzed by comparing the playing and nonplaying humeri of 43 male pre-, peri-, and postpubertal competitive tennis players 10-19 yr of age. Total bone area, medullary area, and cortical area were determined at the mid (40-50%) and distal humerus (60-70%) of both arms using MRI. Humeral bone mass (BMC) was derived from a whole body DXA scan. In prepubertal boys, BMC was 17% greater in the playing compared with nonplaying arm (p < 0.001), which was accompanied by a 12-21% greater cortical area, because of greater periosteal expansion than medullary expansion at the midhumerus and periosteal expansion associated with medullary contraction at the distal humerus. Compared with prepuberty, the side-to-side differences in BMC (27%) and cortical area (20-33%) were greater in peripuberty (p < 0.01). No differences were found between peri- and postpuberty despite longer playing history in the postpubertal players.The osteogenic response to loading was greater in peri- compared with prepubertal boys, which is in contrast with our previous findings in girls and may be caused by differences in training history. This suggests that the window of opportunity to improve bone mass and size through exercise may be longer in boys than in girls.

Profiling the sport consumption attitudes and behaviours of fantasy football players

Most sporting codes encourage participation in Fantasy Sport (FS), despite few making direct revenue from it. There is a lack of empirical evidence whether this is good practice, for although FS can increase involvement and education, it may also compete with other forms of sport consumption for consumers limited resources. This study begins to address whether FS competes with or  complements sport consumption by comparing FS players with nonplayers. Data was collected from surveys (n=182) of AFL fans, with findings indicating FS players had higher tested measures of attitudes (e.g., team identification, commitment) and behaviours (e.g., game attendance, television viewing) related  to the sport. What remains to be determined is causality, and suggestions on how to examine this are given.

Seventy-year-old habitual volleyball players have larger tibial cross-sectional area and may be differentiated from their age-matched peers by the osteogenic index in dynamic performance

The osteogenicity of a given exercise may be estimated by calculating an osteogenic index (OI) consisting of magnitude and rate of strain. Volleyball involves repetitive jumping and requires high power output and thus may be expected to be beneficial to bone and performance. The purpose of the present study was to examine if habitual volleyball playing is reflected in OI. Ten elderly habitual volleyball players [age 69.9 (SD 4.4) years] and ten matched controls volunteered [age 69.7 (4.2) years] as subjects. Distal tibia (d), tibial mid-shaft (50) and femoral neck (F) bone characteristics were measured using pQCT and DXA. To estimate skeletal rigidity, cross-sectional area (ToA50), and compressive (BSId) and bending strength indices (SSImax50) were calculated. Maximal performance was assessed with eccentric ankle plantar flexion, isometric leg press and countermovement jump (CMJ). A fast Fourier transform (FFT) was calculated from the acceleration of the center of mass during the CMJ. Maximal acceleration (MAG) and mean magnitude frequency (MMF) were selected to represent the constituents of OI. OI was calculated as the sum of the products of magnitudes and corresponding frequencies. Volleyball players had 7% larger ToA50 and 37% higher power in CMJ, 15% higher MAG and 36% higher OI (P B 0.047) than the matched controls. No difference was observed in leg press, plantar flexion or the MMF (P C 0.646). In conclusion, habitual volleyball players may be differentiated from their matched peers by their dynamic jumping performance, and the differences are reflected in the magnitude but not rate of loading.

Motives influencing soccer coaching : an empirical study of professional soccer coaches in South Africa

Heightened competition both on a global and national level has raised the bar regarding the expectations that sport organisations have of their coaches. Using the Self-Determination Theory (SOT), which emphasizes the distinction between intrinsically- and extrinsically- driven behaviours, the current study investigated the specific intrinsic and extrinsic factors that motivate professional soccer coaches in South Africa to coach. A non-experimental design using a quantitative approach to assess the motives of individual involvement of coaches in South Africa was employed. The Coach Motivation Scale (CMS) designed to assess motivational factors in coaching was administered to a purposive sample of 112 soccer coaches. Exploratory factor analysis was used to assess the number and nature of factors of the underlying structure of the data. In addition, correlation analysis was conducted on the data set. Both intrinsic and extrinsic motivation correlated significantly with highest academic qualification. Arising from the findings of the study implications for further study are suggested and recommendations made.

Soccer stinger (suspense) SFX

A sound designed stinger featuring a suspense heartbeat to a penalty kick with a goal and crowd cheers with vuvuzelas.

Soccer goal stinger SFX

A stinger featuring a kicked football, vuvuzela and cheering.

Hip adductor muscle strength is reduced preceding and during the onset of groin pain in elite junior Australian football players

Groin pain is a condition with a high prevalence in young Australian football players. It is considered that early identification of this condition allows for optimal management. Eighty-six players from two elite under-age Australian football sides were screened weekly for hip adductor muscle strength, using a hand-held dynamometer and for the onset of groin pain. The maximum variation in the average hip adductor muscle strength values of the sample was a 2.6% decrease from baseline in week 7 of the study. Twelve players (14% of the sample studied) reported groin pain for two consecutive weeks and were considered to have an onset of groin injury. The mean hip adductor muscle strength of these players was decreased significantly from baseline by an average of 11.75 ± 2.50% at the week of pain onset (F = 264.76 (1,11), p < 0.001), and 5.82 ± 5.16% in the week preceding the onset of pain (F = 14.03 (1,10), p = 0.004). These results confirm that hip adductor muscle strength is decreased both preceding and during the onset of groin injury in elite under-age Australian footballers.

Anthropometric profiling of elite junior and senior Australian football players

Purpose: Body structure and physical development must be addressed when preparing junior athletes for their first season in a senior competition. The aim of this preliminary study was to measure the extent of the assumption that final year junior Australian Football (AF) athletes are at a physical mismatch to their senior counterparts.

Methods: Twenty-one male participants (17.71 ± 0.27 y) were recruited from one state based elite junior AF competition and forty-one male participants (22.80 ± 4.24 y) were recruited from one club competing in the senior elite Australian Football League (AFL), who were subsequently divided into two groups; professional rookies aged 18-20 y (19.44 ± 0.70 y; n = 18) and professional seniors aged 21+ y (25.43 ± 3.98 y; n = 23). Dual energy X-ray absorptiometry (DEXA) scans of all participants were completed.

Results: Despite being an average 6.0% and 6.1% lighter in total weight and lean mass respectively, no significant difference was found between the elite junior athletes and their professional AFL rookie counterparts. However, significant differences were demonstrated in comparison with the professional AFL senior athletes (P < .01). Both professional AFL groups demonstrated greater than 0.3 kg total bone mineral content (BMC) than the elite junior athletes (P < .01) and significantly greater segmental BMC and bone mineral density (BMD) results (P < .05).

Conclusion: While the results identify the differences in body composition of the elite junior athletes, development in a linear fashion is noted, providing useful information for the creation of age appropriate expectations and training programs.