Sports2015, 3(3), 236-245; doi:10.3390/sports3030236 (registering DOI) - published 31 August 2015 Show/Hide Abstract
Abstract: Although side-to-side asymmetry of the shoulder rotators calculated by independent peak torque (IPT) has been used for interpretation of injury risks in athletes, it may not measure strength through the entire range of motion (ROM) tested. The aim of this study was to compare side-to-side asymmetry of the shoulder rotators between independent peak torque (IPT) and ten-degree angle specific torque (AST). Twenty healthy adult males (24.65 ± 2.4 years) performed concentric and eccentric internal rotation (IR) and external rotation (ER) of the preferred and non-preferred arms on an isokinetic dynamometer at 60°/s through 150° of total ROM. The total ROM was divided into 14 ten-degree angles of the physiological ROM from −90° of ER to 60° of IR. Concentric and eccentric IR IPT (10.5% ± 8.7% and 12.1% ± 7.2%) and ER IPT (13.6% ± 9.8% and 8.7% ± 5.6%) were significantly less than AST at several angles (p < 0.05). IPT might lead to erroneous interpretations of side-to-side asymmetry in the shoulder rotators and does not represent the entire ROM tested. This information could be used to prescribe strength exercises to enhance overhead performance and reduce risk of shoulder injuries.
Abstract: Extensive challenges are often encountered when recruiting participants to chronic exercise (training) studies. High participant burden during chronic exercise training programmes can result in low uptake to and/or poor compliance with the study. The aim of this qualitative study was to identify factors affecting adolescent girls’ recruitment and adherence to chronic exercise training research studies. Twenty-six adolescent girls (aged 12 to 15 years) participated in one of five focus groups discussing recruitment and retention to exercise physiology research involving a chronic exercise training programme. A thematic analysis was used to analyse the data and eight final themes were inductively identified. Seven evidence-based practical recommendations are suggested to improve the recruitment and retention of participants for prospective, chronic exercise training studies. Successful recruitment requires: (i) the defining of exercise-related terms; (ii) appropriate choice of recruitment material; and (iii) an understanding of participant motivations. Retention strategies include: (iv) regular monitoring of participant motives; and (v) small groups which foster peer and researcher support. Finally, (vi) friendship and ability groups were favoured in addition to (vii) a variety of activities to promote adherence to an exercise training programme.
Abstract: Taper, or reduced-volume training, improves competition performance across a broad spectrum of exercise modes and populations. This article aims to highlight the physiological mechanisms, namely in skeletal muscle, by which taper improves performance and provide a practical literature-based rationale for implementing taper in varied athletic disciplines. Special attention will be paid to strength- and power-oriented athletes as taper is under-studied and often overlooked in these populations. Tapering can best be summarized by the adage “less is more” because maintained intensity and reduced volume prior to competition yields significant performance benefits.
Abstract: This study compared the physiological, perceptual and mechanical responses to kettlebell swings at different loads and swing speeds. Following familiarization 16 strength trained participants (10 males, six females, mean age ± SD = 23 ± 2.9) performed four trials: 2 min kettlebell swings with an 8 kg kettlebell at a fast cadence; 2 min kettlebell swings with an 8 kg kettlebell at a slow cadence; 4 min kettlebell swings with a 4 kg kettlebell at a fast cadence; 4 min kettlebell swings with a 4 kg kettlebell at a slow cadence. Repeated measured analysis of variance indicated no significant differences in peak blood lactate or peak net vertical force across loads and cadences (P > 0.05). Significant main effect for time for heart rate indicated that heart rate was higher at the end of each bout than at mid-point (P = 0.001). A significant Load X cadence interaction for rating of perceived exertion (RPE) (P = 0.030) revealed that RPE values were significantly higher in the 8 kg slow cadence condition compared to the 4 kg slow (P = 0.002) and 4 kg fast (P = 0.016) conditions. In summary, this study indicates that the physiological and mechanical responses to kettlebell swings at 4 kg and 8 kg loads and at fast and slow cadence were similar, whereas the perceptual response is greater when swinging an 8 kg kettlebell at slow cadence.
Abstract: The current study examined the effects of a six-week lumbopelvic-hip complex (LPHC) strengthening program on muscle activation when performing the shoulder dump exercise. The shoulder dump is a total body exercise that includes overhead arm movements. A pre-post test with a control group was implemented. Twenty-seven graduate students (23.5 ± 1.34 yr; 174.4 ± 11.0 cm; 76.6 ± 16.9 kg) participated. Participants were randomly assigned to a control or intervention group where the intervention group performed LPHC exercises. Two-way analysis of variance (ANOVA) revealed a significant increase in muscle activation of the serratus anterior from pre- and post-LPHC intervention, (t = 6.5, p < 0.001). As presented by these data, incorporation of LPHC exercises may assist in facilitating greater activation in some of the scapula-stabilizing musculature that has traditionally been rehabilitated in prone or side-lying positions. It is, therefore, suggested that LPHC exercises be incorporated in a regular shoulder rehabilitation program.
Abstract: Studies have shown that advanced rock climbers have greater upper body strength than that of novice climbers or non-climbers. The purpose of this study was to compare upper body strength between rock climbing and resistance trained men. Fifteen resistance trained men (age 25.28 ± 2.26 yrs; height 177.45 ± 4.08 cm; mass 85.17 ± 10.23 kg; body fat 10.13 ± 5.40%) and 15 rock climbing men (age 23.25 ± 2.23 yrs; height 175.57 ± 8.03 cm; mass 66.66 ± 9.40 kg; body fat 6.86 ± 3.82%) volunteered to participate. Rock climbing (RC) men had been climbing for at least two years, 2–3 times a week, able to climb at least a boulder rating of V4–5 and had no current injuries. Resistance trained (RT) men had been total body strength training for at least two years, 2–3 times a week with no current injuries. Each participant performed pull-ups to failure, grip strength, and pinch strength. RT were significantly older and heavier than RC. RC performed significantly more pull-ups (19.31 ± 4.31) than RT (15.64 ± 4.82). RC had greater relative pinch strength (R 0.27 ± 0.10 kg/kg; L 0.24 ± 0.07 kg/kg) than RT (R 0.19 ± 0.04 kg/kg; L 0.16 ± 0.05 kg/kg) and greater relative grip strength (R 0.70 ± 0.10 kg/kg; L 0.65 ± 0.12 kg/kg) than RT (R 0.57 ± 0.14 kg/kg; L 0.56 ± 0.15 kg/kg). Overall, RC men demonstrated greater performance in tests involving relative strength when compared to RT men. Rock climbing can promote increased upper body strength even in the absence of traditional resistance training.