Common variants of the resistance mechanism in the Smith Machine: analysis of mechanical loading characteristics and application to strength-oriented and hypertrophy-oriented training

The Smith machine is a pervasive weight-training apparatus, used extensively by a wide population of weight trainers, from novices to high-level athletes. The advantages of using a Smith machine over free-weight resistance are disputed, with conflicting findings reported in the literature. In this study, we are interested in practical differences between 3 types of loading mechanisms found in modern Smith machines. In addition to the basic design comprising a constrained weighted barbell, alterations with a counterweight and a viscous resistance component are examined. The approach taken is that of employing a recently proposed representation of force characteristics that may be exhibited by a trainee and a predictive model of thus effected adaptation. A computer simulation is used to predict the effects of the 3 linear Smith machine designs in the framework of different exercise protocols. Our results demonstrate that each resistance component, vertically constrained load, counterweight, and viscous, can be matched with a particular training context, in which it should be preferred. Thus, a number of practical guidelines for weight-training practitioners are recommended. In summary, (a) at low intensities (55–75% of 1 repetition maximum [1RM]) used in strength-endurance training, a viscous resistance containing the Smith machine was found to offer advantages over both a constrained load only and counterweighted designs; (b) at medium intensities (75–85% of 1RM) typically employed in hypertrophy-specific training, the counterweighted Smith machine design was found to offer the best choice in terms of high-force development and total external work performed; finally, (c) at high training intensity (90–100% of 1RM), the optimal prescription was found to be more dependent on the specific athlete’s weaknesses, highlighting the need for continual monitoring of the athlete’s force production capabilities. To ensure that appropriate adjustments are made to the athlete’s training regimen, the practitioner should consider the full set of findings of this article and the accompanying discussion.

Cardiac adaptation to endurance exercise in rats

Endurance exercise is widely assumed to improve cardiac function in humans. This project has determined cardiac function following endurance exercise for 6 (n = 30) or 12 (n = 25) weeks in male Wistar rats (8 weeks old). The exercise protocol was 30 min/day at 0.8 km/h for 5 days/week with an endurance test on the 6th day by running at 1.2 km/h until exhaustion. Exercise endurance increased by 318% after 6 weeks and 609% after 12 weeks. Heart weight/kg body weight increased by 10.2% after 6 weeks and 24.1% after 12 weeks. Echocardiography after 12 weeks showed increases in left ventricular internal diameter in diastole (6.39 ± 0.32 to 7.90 ± 0.17 mm), systolic volume (49 ± 7 to 83 ± 11 μl) and cardiac output (75 ± 3 to 107 ± 8 ml/min) but not left wall thickness in diastole (1.74 ± 0.07 to 1.80 ± 0.06 mm). Isolated Langendorff hearts from trained rats displayed decreased left ventricular myocardial stiffness (22 ± 1.1 to 19.1 ± 0.3) and reduced purine efflux during pacing-induced workload increases. 31P-NMR spectroscopy in isolated hearts from trained rats showed decreased PCr and PCr/ATP ratios with increased creatine, AMP and ADP concentrations. Thus, this endurance exercise protocol resulted in physiological hypertrophy while maintaining or improving cardiac function.

Hospital readmission among older adults with congestive heart failure

Older adults with congestive heart failure [CHF] are likely to experience multiple readmissions to hospital. There have been several studies conducted on hospital readmissions; however, generalising the findings is problematic due to the use of variable definitions of what constitutes a readmission. This paper addresses the absence of Australian research comparing groups of older patients with CHF who are readmitted to hospital with those who are not readmitted. It also adopts one of the more frequently used definitions of readmission to aid in future comparability of research. Using a comparative cohort design, a multivariate logistic regression model was used to compare readmitted patients with non-readmitted patients and identify risk factors associated with readmission. Significant risk factors identified were male gender, numerous diagnoses, lengths of stay of 3 days or longer and admission from acute, subacute or aged care facilities. The increased likelihood of readmission among patients from acute, subacute and aged care services warrants further investigation.

Instant rivalry: the Melbourne Victory versus Melbourne Heart derby

The Australian A-League football (soccer) competition only began in 2005 after a major reconstruction of the governance of the game. The model adopted was one team per city so local derbies, often the focus of intense and long-running rivalries in football overseas, did not exist. In 2010 a second team began in Melbourne where previously Melbourne Victory had a monopoly. Within a couple of seasons an intense local rivalry has developed attracting over 40,000 fans to games between Victory and newcomer Melbourne Heart. This is the story of that rivalry and how it has become one of the most eagerly anticipated sporting occasions in a country where historically soccer has been a minority sport.