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Horizontal single-leg drop jumps (SLDJ) have previously been shown to be effective at improving sprinting performance, but the optimal dose is debateable. Therefore, the purpose of this study was to compare moderately-low volume (MLV: 30 -70 ground contacts (GC .session-1)) and ultra-low (ULV: 10 - 28 GC.session-1) volume protocols for improving sprint performance. Two experimental groups (MLV = 11; ULV = 11), consisting of high-level male academy and semi-professional rugby players, underwent twice-weekly horizontal SLDJ training for four weeks, with concurrent rugby and resistance training. Plyometric volumes for both groups were progressed for three weeks with a 30% reduction the fourth week. Maximal vertical jump and sprint assessments were performed pre- and post-intervention. There were no significant differences at baseline for any variable (p > 0.05). An analysis of variance (ANOVA) was performed to detect changes between- and within-subjects. There was a significant training interaction between groups for 10- and 30-m sprint performance. While MLV significantly decreased 10-, 20-, and 30- m times (-0.03 to -0.05s; ES= 0.32 – 0.54), ULV did not significantly change split times at any distance (p > 0.05). There was a small non-significant decrease in maximal velocity only in the ULV group (-1.79%), while both groups were able to produce substantial improvements in vertical jumping performance with no between-group differences (+14.7 – 38.4%; ES: -0.67 to 1.12). In conclusion, adding MLV protocols may preferentially improve sprint performance and maintain maximal velocity characteristics when compared to ULV protocols. However, higher volumes did not additionally improve vertical jump performance more so than low volumes. [ABSTRACT FROM AUTHOR]

The aim of this investigation was to explore the relationship between physical capacity and match running performance in professional Japanese rugby union players. Fifty professional players participated in this study with physical measures including; anthropometric values, vertical jump (VJ), 30 cm drop jump, broad jump (BJ), 10 m and 20 m sprint times, YoYo intermittent recovery test level 1 (YYIRT1) and one repetition maximum strength values collected. Match running performance was measured using Global Positioning Systems. Multiple significant relationships were found between physical capacity and match running performance. Match running percentage >5 m·s-1 was highly correlated (p < 0.01) with sprint times and jump height measures of VJ (r = 0.63), BJ (r = 0.59), 10 m (r = -0.63) and 20 m (r = -0.70). Similar relationships were found between VJ and total distance >5m·s-1 (r=0.60) and maximum velocity (0.42). Regression equations were also used to investigate predictive capabilities of physical capacity outcomes and match running performance. Significant relationships were found between performance variables and several match running outcomes including total distance, m·min-1, maximal running velocity, and movements above 5 m·s-1. For instance, it was identified that YYIRTL1 was predictive of total distance covered in matches (p =0.001). With this regression equations highlighting a two-shuttle improvement (80m) in the YYIRTL1 potentially able to contribute to a 1.5% change in total distance covered per game. These findings emphasise the importance of developing physical capacity, particularly through the lower body, as there are clear links with these physical capacities and match running performance. [ABSTRACT FROM AUTHOR]

Lower limb injuries are common in sport and have a mechanical aetiology, either via acute or chronic loading to musculoskeletal tissue. Cumulative loading influences the onset and severity of injuries such as fatigue fracture or tendinopathy but is difficult to measure in the field. A field-based, simple method to quantify and monitor mechanical loads using wearable sensors may be the first step in the prevention and management of lower limb musculoskeletal injury. Furthermore, the application of a load metric based on concepts of musculoskeletal mechanobiology should be integrated within the load measurement system to account for tissue adaptation. Musculoskeletal tissue is influenced by mechanical loads, such that the loads can either be positive, leading to enhanced structural integrity; or harmful, resulting in injuries or disease. The purpose of this paper is to review the influence of cumulative lower limb mechanical load on musculoskeletal tissue homeostasis and injury risk and examine appropriate methods to quantify cumulative lower limb load in the field. Using the data in this way, coaches may be able to decrease musculoskeletal tissue load based on changes in training and mechanics more effectively than with counts of tasks, speed, or distance alone. Additionally, regular monitoring using the proposed methods may be useful in evaluating limb symmetry and fatiguerelated changes. [ABSTRACT FROM AUTHOR]

An eccentric muscle action involves the lengthening of a muscle due to an external load and occurs as a result of the mechanical disruption of action and myosin. The mechanical nature of the actin and myosin disruption during eccentric muscle actions is reported to allow for greater force production and requires a different neural activation pattern from a concentric action. As a consequence of these differences it is suggested concentric focused resistance training may not overload the eccentric action sufficiently. Therefore the purpose of this review was to outline a variety of eccentric training modalities and provide the reader with practical recommendations on programming. A search of the literature was conducted for; eccentric; training; methods; cycling; isokinetics; drop jumps; flywheel; exercise induced muscle damage; repeated bout effect. After this search 106 papers were selected to form the basis of this review. When training isokinetically it was reported six to ten weeks of training at 180° s-1, three times per week and with 24 - 30 maximal contractions per session resulted in improved hypertrophy and eccentric strength. When using dynamic exercises such as the squat and bench press a barbell load of 75 - 85% concentric 1RM with a releaser load of 40 - 55% (5 - 10 repetitions, 45 - 90 seconds between repetitions) may be appropriate. If the eccentric training is submaximal the barbell load has been recommended to be 50 - 65% concentric 1RM with a releaser load of 10 - 25% (15 - 20 repetitions, 15 - 30 seconds between repetitions). In conclusion eccentric training may warrant inclusion as part of an athletes training program. [ABSTRACT FROM AUTHOR]

Eccentric training has the ability to improve strength and power as well as being a stimulus for hypertrophy gains. However a possible negative side effect is exercise induced muscle damage, which can have a detrimental effect on performance. The symptoms and causes of exercise induced muscle damage and the ability of the RBE to protect against muscle damage are discussed in this review. A search of the literature was conducted for; eccentric; training; methods; exercise induced muscle damage (EIMD); RBE. After this search 82 papers were selected to form the basis of this review. The finding of this review suggest if isometric contractions are used as a preconditioning exercise these should be completed at long muscle lengths with 10 isometric contractions reported to result in the greatest protective effect. Results of previous studies indicate that 30 repetitions of eccentric contractions at 10 - 40% maximal isometric strength (low intensity and volume) and ~4 s in duration have resulted in a RBE with little initial damage. Studies that have investigated low volume maximal eccentric contractions (6 - 24 reps, ~ 4 s in duration) have reported increased initial EIMD followed by a protective effect against further damage. When utilising maximal eccentric contractions the protective effect is reported to last up to 6 months in comparison to a low intensity bout that may only offer protection for 3 weeks. In summary it is suggested athletes should initially complete low intensity low volume eccentric training. Athletes should then progress to low load maximal or supramaximal eccentric training prior to completing higher volume sessions to allow the RBE to offer protection against muscle damage. [ABSTRACT FROM AUTHOR]

The article presents a study which investigates the relationship between the measures of the session rating of perceived exertion (RPE) and the volume load during resistance training (RT). The study uses the calculation of VL by multiplying the total repetitions by the amount of weight lifted top determine the training volume for each session. Results show that the RPE method is a simply was to monitor the VL during the undulated periodised RT program.

The article presents a study on the relationship between intensive training, injury and illness at an Australian Football League Club (AFL). It cites ways training load was measured. It was found that 42 percent of illnesses were linked with a preceding spike in training load while 40 percent of injuries were linked with training load. The findings indicate that proper monitoring training load using Rating of Perceived Exertion (RPE) can provide some information on when illnesses and injuries may occur.

The article reports on the results of a research to determine whether or not depth-jump training improved jumping abilities of elite volleyball players. A training group and a control group were formed. Variables included counter-movement vertical jump (CMVJ), spike jump (SPJ) and spike jump contribution quotients. The results showed that depth jump training significantly improved jumping abilities of elite volleyball players on all variables more than other jump training methods when combined with regular strength and conditioning programs.

The article focuses on a study to determine the best method of measuring dynamic and isometric strengths of national level soccer players. Fifty-six male national soccer players were chosen as subjects. The Pearson Product Correlation Coefficient was used to examine variables including maximal isometric force (PF), rate of force development (RFD), jump power, and one repetition maximum (1RM) strength. Results showed that the isometric mid thigh pull proved to be the appropriate means of assessing both isometric and dynamic strength of soccer players.

The article presents observations of long-power curves in the hang power clean of three representative athletes of the men's hockey squad at Western Australian Institute of Sport. It notes that the changes in capability of power output and one repetition maximum were different in each athlete. Also, each athlete was observed to exhibit relatively similar power output values across the range of light to heavy loads during the hang power clean. The implication of the research finding is also cited.

The article provides information on aspects related to association between powerlifting competition and accessory exercises utilized in training. Topics discussed include weakness trageting and competitive movements, measurements of standard deviations, recruitment of weaker participants, and accessory movements.