This study may encourage further research to confirm the usefulness of very-heavy sled in this context.

Mechanical relationships can be accurately profiled using common sled-training equipment. Notably, the optimal loading conditions determined in this study (69-96% of BM, dependent on friction conditions) represent much greater resistance than current guidelines (~7-20% of BM). This method has potential value in quantifying individualized training parameters for optimized development of horizontal power.

No abstract

Past participation in rugby or a history of concussion were associated with small to moderate neurocognitive deficits (as indicated by worse CNS Vital Signs scores) in athletes post retirement from competitive sport.

AimsIn the current study we investigated the effects of resisted sprint training on sprinting performance and underlying mechanical parameters (force-velocity-power profile) based on two different training protocols: (i) loads that represented maximum power output (Lopt) and a 50% decrease in maximum unresisted sprinting velocity and (ii) lighter loads that represented a 10% decrease in maximum unresisted sprinting velocity, as drawn from previous research (L10).MethodsSoccer [n = 15 male] and rugby [n = 21; 9 male and 12 female] club-level athletes were individually assessed for horizontal force-velocity and load-velocity profiles using a battery of resisted sprints, sled or robotic resistance respectively. Athletes then performed a 12-session resisted (10 × 20-m; and pre- post-profiling) sprint training intervention following the L10 or Lopt protocol.ResultsBoth L10 and Lopt training protocols had minor effects on sprinting performance (average of -1.4 to -2.3% split-times respectively), and provided trivial, small and unclear changes in mechanical sprinting parameters. Unexpectedly, Lopt impacted velocity dominant variables to a greater degree than L10 (trivial benefit in maximum velocity; small increase in slope of the force-velocity relationship), while L10 improved force and power dominant metrics (trivial benefit in maximal power; small benefit in maximal effectiveness of ground force orientation).ConclusionsBoth resisted-sprint training protocols were likely to improve performance after a short training intervention in already sprint trained athletes. However, widely varied individualised results indicated that adaptations may be dependent on pre-training force-velocity characteristics.

What housing and service interventions work best to reduce homelessness for families in the United States? The FamilyOptions Study randomly assigned 2,282 families recruited in homeless shelters across 12 sites to priority access to one of three active interventions or to usual care in their communities. The interventions were long-term rent subsidies, short-term rent subsidies, and transitional housing in supervised programs with intensive psychosocial services. In two waves of follow-up data collected 20 and 37 months later, priority access to long-term rent subsidies reduced homelessness and food insecurity and improved other aspects of adult and child well-being relative to usual care, at a cost 9 percent higher. The other interventions had little effect. The study provides support for the view that homelessness for most families is an economic problem that long-term rent subsidies resolve and does not support the view that families must address psychosocial problems to succeed in housing. It has implications for focusing government resources on this important social problem. C 2018 by the Association for Public Policy Analysis and Management.

Protein needs for energy-restricted resistance-trained athletes are likely 2.3-3.1g/kg of FFM scaled upwards with severity of caloric restriction and leanness.

In this elite sample, rugby union athletes typically displayed greater short-distance sprint performance, which may be linked to an ability to generate high levels of horizontal force and power. The acceleration characteristics presented in this study could be a result of the individual movement and positional demands of each code.