Effects of glucose–fructose versus glucose ingestion on stride characteristics during prolonged treadmill running

Scarce research has examined the effects of carbohydrate composition on running stride characteristics. On two occasions, 14 males and 6 females completed a 120-min sub-maximal run followed by a 4-mile time trial. Participants consumed glucose (GLU) or glucose–fructose (GLU–FRU) beverages supplying 1.3 g/min carbohydrate. Substrate use, psychological affect [Feeling Scale (FS)], and stride characteristics (stride frequency, stride length, and contact time) were assessed. Effects were expressed as Cohen’s d (90% confidence limits [90% CL]). CLs for stride frequency differences at 53 min (90% CL = 0.04–0.21) and 113 min (90% CL = 0.02–0.24) did not cover 0, indicating a positive effect of GLU–FRU. However, effect sizes were small (d = 0.13) and likely-to-very-likely trivial. Energy expenditure differences at sub-maximal end were very likely trivial (d = 0.08; 90% CL = 0.00–0.17), while FS ratings were possibly higher for GLU–FRU at 50 (d = 0.19; 90% CL = ?0.10–0.48) and 110 min (d = 0.16; 90% CL = ?0.13–0.45). During the time trial, stride length was possibly higher with GLU–FRU (d = 0.13; 90% CL = ?0.08–0.33). Glucose–fructose co-ingestion has no significant effect on stride characteristics during constant-velocity running but may result in slightly higher stride length during self-paced running.     

The kinematic differences between off-spin and leg-spin bowling in cricket

Spin bowling is generally coached using a standard technical framework, but this practice has not been based upon a comparative biomechanical analysis of leg-spin and off-spin bowling. This study analysed the three-dimensional (3D) kinematics of 23 off-spin and 20 leg-spin bowlers using a Cortex motion analysis system to identify how aspects of the respective techniques differed. A multivariate ANOVA found that certain data tended to validate some of the stated differences in the coaching literature. Off-spin bowlers had a significantly shorter stride length (p = 0.006) and spin rate (p = 0.001), but a greater release height than leg-spinners (p = 0.007). In addition, a number of other kinematic differences were identified that were not previously documented in coaching literature. These included a larger rear knee flexion (p = 0.007), faster approach speed (p < 0.001), and flexing elbow action during the arm acceleration compared with an extension action used by most of the off-spin bowlers. Off-spin and leg-spin bowlers also deviated from the standard coaching model for the shoulder alignment, front knee angle at release, and forearm mechanics. This study suggests that off-spin and leg-spin are distinct bowling techniques, supporting the development of two different coaching models in spin bowling.     

Effects of coffee and caffeine anhydrous on strength and sprint performance

Caffeine and coffee are widely used among active individuals to enhance performance. The purpose of the current study was to compare the effects of acute coffee (COF) and caffeine anhydrous (CAF) intake on strength and sprint performance. Fifty-four resistance-trained males completed strength testing, consisting of one-rep max (1RM) and repetitions to fatigue (RTF) at 80% of 1RM for leg press (LP) and bench press (BP). Participants then completed five, 10-second cycle ergometer sprints separated by one minute of rest. Peak power (PP) and total work (TW) were recorded for each sprint. At least 48 hours later, participants returned and ingested a beverage containing CAF (300?mg flat dose; yielding 3–5?mg/kg bodyweight), COF (8.9?g; 303?mg caffeine), or placebo (PLA; 3.8?g non-caloric flavouring) 30 minutes before testing. LP 1RM was improved more by COF than CAF (p?=?.04), but not PLA (p?=?.99). Significant interactions were not observed for BP 1RM, BP RTF, or LP RTF (p?>?.05). There were no sprint?×?treatment interactions for PP or TW (p?>?.05). 95% confidence intervals revealed a significant improvement in sprint 1 TW for CAF, but not COF or PLA. For PLA, significant reductions were observed in sprint 4 PP, sprint 2 TW, sprint 4 TW, and average TW; significant reductions were not observed with CAF or COF. Neither COF nor CAF improved strength outcomes more than PLA, while both groups attenuated sprint power reductions to a similar degree. Coffee and caffeine anhydrous may be considered suitable pre-exercise caffeine sources for high-intensity exercise.     

Effects of environmental intervention on sedentary time,musculoskeletal comfort and work ability in office workers

Sit–stand workstations offer a potential strategy to reduce prolonged occupational sitting. This controlled intervention study examined the effects of an environmental intervention on occupational sedentary time, musculoskeletal comfort and work ability, and the usability of sit–stand workstations in office work via a self-reported questionnaire. The intervention group (n?=?24) used sit–stand workstations during the 6-month intervention period, and the control group (n?=?21) used traditional sitting workstations. The results showed that working at sit–stand workstations can reduce sitting time significantly compared to control workstations (?6.7% vs. 5.0%, p?=?.019), which is reallocated mostly to standing (r?=??0.719, p?p?=?.028), as well as work ability (p?=?.022). The majority of intervention subjects rated sit–stand workstation adjustability as good (83.3%), and 75.0% were satisfied with the workstation. About 41.7% of the intervention participants, who were exclusively female, used the sit–stand function on a daily basis. While the environmental change alone was effective, it is likely that promoting the daily use of sit–stand workstations with counselling would lead to even more substantial positive effects.     

How much does lower body strength impact Paralympic running performance?

Objectives: Development of evidence-based methods of Paralympic classification requires research quantifying the relative strength of association between ratio-scaled measures of impairment and athletic performance. The purpose of this study was to quantify the extent to which muscle strength affects running performance in runners with and without brain impairment. Design: Cross-sectional study. Methods: Participants were 41 male runners: 13 with brain impairments (RBI) and 28 non-disabled (NDR). All participants completed a maximal 60-m sprint and a novel battery of three lower limb isometric strength tests. Results: RBI showed significantly lower strength scores compared with NDR on the more affected side in leg flexion (176 vs. 243?N), leg extension (993 vs. 1661?N) and plantarflexion (824 vs. 1457?N). Significant differences were also seen on the less affected side in plantarflexion (1072 vs. 1508?N). RBI were significantly slower in the acceleration phase (0–15?m) (3.2?s?±?0.3?vs. 2.8?s?±?0.2) and top speed phase (30?60?m) (4.3?s?±?0.6?vs. 3.8?s?±?0.3). Correlation analysis showed stronger relationships between strength and running performance in RBI than NDR; however, the correlations were not significant. Conclusions: This study evaluated measures to assess strength for the purposes of classification and found that the measures were significantly different in RBI compared with NDR indicating the tests were able to capture strength impairment in this population. This study indicates that strength may be an important impairment type to assess in this population, as impairments of muscle strength may influence the outcome of running performance in athletes with more severe impairments.     

Effect of repeat-sprint training in hypoxia on post-exercise interleukin-6 and F2-isoprostanes

This investigation examined the oxidative stress (F₂-Isoprostane; F₂-IsoP) and inflammatory (interleukin-6; IL-6) responses to repeat-sprint training in hypoxia (RSH). Ten trained male team sport athletes performed 3(sets)*9(repetitions)*5?s cycling sprints in simulated altitude (3000?m) and sea-level conditions. Mean and peak sprint power output (MPO and PPO) were recorded, and blood samples were collected pre-exercise, and again at 8 and 60?min post-exercise. Both MPO and PPO were significantly reduced in hypoxia (compared to sea-level) in the second (MPO: 855?±?89 vs. 739?±?95?W, p?=?.006; PPO: 1024?±?114 vs. 895?±?112?W, p?=?.010) and third (MPO: 819?±?105 vs. 686?±?83?W, p?=?.008; PPO: 985?±?125 vs. 834?±?99?W, p?=?.008) sets, respectively. IL-6 was significantly increased from pre- to 1?h post-exercise in both hypoxia (0.7?±?0.2 vs. 2.4?±?1.4?pg/mL, p?=?.004) and sea-level conditions (0.7?±?0.2 vs. 1.6?±?0.3?pg/mL, p?d?=?0.80) suggesting higher IL-6 levels of post-hypoxia. F₂-IsoP was significantly lower 1?h post-exercise in both the hypoxic (p?=?.005) and sea-level (p?=?.002) conditions, with no differences between trials. While hypoxia can impact on exercise intensity and may result in greater post-exercise inflammation, it appears to have little effect on oxidative stress. These results indicate that team sport organisations with ready access to hypoxic training facilities could confidently administer RSH without significantly increasing the post-exercise inflammatory or oxidative stress response.     

The fourth dimension: A motoric perspective on the anxiety–performance relationship

This article focuses on raising concern that anxiety–performance relationship theory has insufficiently catered for motoric issues during, primarily, closed and self-paced skill execution (e.g., long jump and javelin throw). Following a review of current theory, we address the under-consideration of motoric issues by extending the three-dimensional model put forward by Cheng, Hardy, and Markland (2009) (‘Toward a three-dimensional conceptualization of performance anxiety: Rationale and initial measurement development, Psychology of Sport and Exercise, 10, 271–278). This fourth dimension, termed skill establishment, comprises the level and consistency of movement automaticity together with a performer's confidence in this specific process, as providing a degree of robustness against negative anxiety effects. To exemplify this motoric influence, we then offer insight regarding current theories’ misrepresentation that a self-focus of attention toward an already well-learned skill always leads to a negative performance effect. In doing so, we draw upon applied literature to distinguish between positive and negative self-foci and suggest that on what and how a performer directs their attention is crucial to the interaction with skill establishment and, therefore, performance. Finally, implications for skill acquisition research are provided. Accordingly, we suggest a positive potential flow from applied/translational to fundamental/theory-generating research in sport which can serve to freshen and usefully redirect investigation into this long-considered but still insufficiently understood concept.     

What’s your goal? The importance of shaping the goals of engineering tasks to focus learners on the underlying science

Instructional Science - Engaging in engineering tasks can help students learn science concepts. However, many engineering tasks lead students to focus more on the success of their construction than...     

Teaching Them to Teach: Programmatic Evaluation of Graduate Assistants’ Teaching Performance

Academic libraries are one of the most important sources of “on the job” training for future library instructors. Librarians who supervise and assess these future library instructors (often in graduate assistant positions) often choose to provide observations and feedback each semester to these instructors in training. Scholarly literature, however, provides little information on whether this system helps graduate assistants to develop as teachers. The authors of this article assessed graduate assistants’ performance as teachers over three semesters using a system of observation and self-assessment. They analyzed both patterns and areas of growth and discuss the strengths and weaknesses of this system.     

Are you a budding academic writer?

Academic writing can seem a daunting prospect although with the right support and information it can be more achievable than you think. In this first set of editorial comments of 2016, editors from all sections of the Health Information and Libraries Journal outline the origins of the individual section of the journal which they oversee and highlight some of the things you might want to consider when thinking of submitting your writing for publication.