Background: Effects of resistance training on muscle strength and hypertrophy are wellestablished in adults and younger elderly. However, less is currently known about these effects in the very elderly (i.e., 75 years of age and older).Objective: To examine the effects of resistance training on muscle size and strength in very elderly individuals.Methods: Randomized controlled studies that explored the effects of resistance training in very elderly on muscle strength, handgrip strength, whole-muscle hypertrophy, and/or muscle fiber hypertrophy were included in the review. Meta-analyses of effect sizes (ESs) were used to analyze the data.Results: Twenty-two studies were included in the review. The meta-analysis found a significant effect of resistance training on muscle strength in the very elderly (difference in ES = 0.97; 95% confidence interval [CI]: 0.50, 1.44; p = 0.001). In a subgroup analysis that included only the oldest-old participants (80+ years of age), there was a significant effect of resistance training on muscle strength (difference in ES = 1.28; 95% CI: 0.28, 2.29; p = 0.020). For handgrip strength, we found no significant difference between resistance training and control groups (difference in ES = 0.26; 95% CI: -0.02, 0.54; p = 0.064). For wholemuscle hypertrophy, there was a significant effect of resistance training in the very elderly (difference in ES = 0 30; 95% CI: 0.10, 0.50; p = 0.013). We found no significant difference in muscle fiber hypertrophy between resistance training and control groups (difference in ES = 0.33; 95% CI: -0.67, 1.33; p = 0.266). There were minimal reports of adverse events associated with the training programs in the included studies. 3 Conclusions: We found that very elderly can increase muscle strength and muscle size by participating in resistance training programs. Resistance training was found to be an effective way to improve muscle strength even among the oldest-old. Key points: ►We found that very elderly adults can increase their muscle strength and size by participating in resistance training programs. ►These effects were observed with resistance training interventions that generally included low weekly training volumes and frequencies. ►There were minimal reports of adverse events associated with the training programs.

This meta-analysis found significant ergogenic effects of sodium bicarbonate supplementation on muscular endurance of both small and large muscle groups.2. No significant ergogenic effects of sodium bicarbonate were found for muscular strength.3. No significant linear trends in the effects of timing of sodium bicarbonate ingestion or acute increase in blood bicarbonate concentrations on muscular endurance or muscular strength were found.

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Objectives: To conduct a systematic review and a meta-analysis of studies exploring the effects of caffeine and/or sodium bicarbonate on performance in the Yo-Yo test. Design: Systematic review and meta-analysis. Methods: A total of six databases were searched, and random-effects meta-analyses were performed examining the isolated effects of caffeine and sodium bicarbonate on performance in the Yo-Yo test. Results: After reviewing 988 search records, 15 studies were included. For the effects of caffeine on performance in the Yo-Yo test, the meta-analysis indicated a significant favoring of caffeine as compared with the placebo conditions (p = 0.022; standardized mean difference [SMD] = 0.17; 95% CI: 0.08, 0.32; +7.5%). Subgroup analyses indicated that the effects of caffeine were significant for the level 2 version of the Yo-Yo test, but not level 1. Four out of the five studies that explored the effects of sodium bicarbonate used the level 2 version of the Yo-Yo test. The pooled SMD favored the sodium bicarbonate condition as compared with the placebo/control conditions (p = 0.007; SMD: 0.36; 95% CI: 0.10, 0.63; +16.0%). Conclusions: This review demonstrates that isolated ingestion of caffeine and sodium bicarbonate enhances performance in the Yo-Yo test. Given these ergogenic effects, the intake of caffeine and sodium bicarbonate before the Yo-Yo test needs to be standardized (i.e., either restricted or used in the same way before each testing session). Furthermore, the results suggest that individuals competing in sports involving intermittent exercise may consider supplementing with caffeine or sodium bicarbonate for acute improvements in performance.

Scaling sports equipment to match the physical development of children allows motor skills to be performed with greater success and with more desirable movement patterns. It is unknown, however, how scaled equipment affects movement variability -a key factor associated with coordination. Our aim was to identify whether scaled sports equipment facilitates coordination and functional movement variability in children when performing a hitting for accuracy task in tennis. Twenty-five children were asked to execute a forehand stroke with the aim of hitting the ball to a target located 10 metres away. Participants performed the task in two conditions -a scaled equipment condition and a full-sized equipment condition. Scaled equipment led to superior hitting accuracy and greater temporal stability of the swing compared to full-sized equipment. Scaled equipment also afforded the emergence of a functional coupling between upper arm and forearm movement variability which helped regulate the distance between the shoulder and the racket. comparatively there was a lack of coupling when full-sized equipment was used. Hence, scaled equipment promoted functional movement variability, whereas full-sized equipment resulted in the freezing of mechanical degrees of freedom. this suggests that children's skill acquisition could be hindered and potentially regress when using inappropriately sized equipment.The benefits of scaling sports equipment are well documented 1 . By matching the size of equipment to the developmental stage of a player, skills are performed with more success and with more desirable movement patterns 2-7 . This literature, however, is limited by a tendency to focus predominately on performance outcome measures and/ or subjective assessments of movement patterns e.g., 2,3 . It is therefore unclear how equipment affects the coordination of movement with specific reference to functional movement variability -a factor that likely underpins the benefits of scaled equipment for children. The expectation is that appropriately sized equipment facilitates the ability to coordinate movements.An impressive feature of neurobiological systems is the ability to coordinate multiple joints with abundant degrees of freedom to produce functional movements 8 . According to dynamical systems theory, complex systems -such as a movement system -self organise according to the constraints surrounding the system 9,10 . This self-organisation process allows multiple body parts to coordinate with each other and afford functional movements to emerge. For instance, movements of an individual self-organise based on the confluence of task, individual and environmental constraints 11 . In cricket, reducing the pitch length -a task constraint -resulted in children adopting a bowling technique with less shoulder counter-rotation, which is considered more efficient and less likely to cause injury 12 . Likewise, in tennis, smaller rackets and lower compression balls led to a greater proportion of balls struck out in front of the body and with a low...