Exercise Testing

Background: Plyometric training is an effective method to prevent knee injuries in female athletes, however the effects of plyometric training on jump performance in female athletes is unclear.
Objective: The aim of this systematic review and meta-analysis was to determine the effectiveness of plyometric training on vertical jump performance of amateur, collegiate and elite female athletes.
Methods Six electronic databases were searched (PubMed, MEDLINE, ERIC, Google Scholar, SCIndex and ScienceDirect).  The included studies were coded for the following criteria: training status, training modality and type of outcome measures. The methodological quality of each study was assessed using the Physiotherapy Evidence Database (PEDro) scale. The effects of plyometric training on vertical jump performance were based on the following standardised pre-post testing effect size (ES) thresholds: trivial (<0.20), small (0.21-0.60), moderate (0.61-1.20), large (1.21-2.00), very large (2.01-4.00) and extremely large (>4.00).
Results: A total of 16 studies met the inclusion criteria. The meta-analysis revealed that plyometric training had a most likely moderate effect on countermovement jump (CMJ) height performance (ES = 1.09; 95% confidence interval [CI] 0.57 to 1.61; I2 = 75.60%). Plyometric training interventions of less than 10 weeks in duration had a most likely small effect on CMJ height performance (ES = 0.58; 95% CI 0.25 to 0.91). In contrast, plyometric training durations greater than 10 weeks had a most likely large effect on CMJ height (ES = 1.87; 95% CI 0.73 to 3.01). The effect of plyometric training on concentric-only squat jump (SJ) height was likely small (ES = 0.44; 95% CI -0.09 to 0.97). Similar effects were observed on SJ height after 6 weeks of plyometric training in amateur (ES = 0.35) and young (ES = 0.49) athletes, respectively. The effect of plyometric training on CMJ height with the arm swing was likely large (ES = 1.31; 95% CI -0.04 to 2.65). The largest plyometric training effects were observed in drop jump (DJ) height performance (ES = 3.59; 95% CI -3.04 to 10.23). Most likely extremely large plyometric training effects on DJ height performance (ES = 7.07; 95% CI 4.71 to 9.43) were observed following 12 weeks of plyometric training. In contrast, a possibly small positive training effect (ES = 0.30; 95% CI –0.63 to 1.23) was observed following 6 weeks of plyometric training.
Conclusion: Plyometric training is an effective form of training to improve vertical jump performance (e.g. CMJ, SJ and DJ) in female athletes. The benefits of plyometric training on vertical jump performance are greater for interventions of longer duration (≥10 weeks).

The incremental shuttle walk test (ISWT) is used to assess functional capacity of patients entering cardiac rehabilitation. Factors such as age and sex account for a proportion of the variance in test performance in healthy individuals but there are no reference values for patients with cardiovascular disease. The aim of this study was to produce reference values for the ISWT. Participants were n = 548 patients referred to outpatient cardiac rehabilitation who underwent a clinical examination and performed the ISWT. We used regression to identify predictors of performance and produced centile values using the generalised additive model for location, scale and shape model. Men walked significantly further than women (395 ± 165 vs. 269 ± 118 m; t = 9.5, P < 0.001) so data were analysed separately by sex. Age (years) was the strongest predictor of performance in men (β = −5.9; 95% CI: −7.1 to −4.6 m) and women (β = −4.8; 95% CI: −6.3 to 3.3). Centile curves demonstrated a broadly linear decrease in expected ISWT values in males (25–85 years) and a more curvilinear trend in females. Patients entering cardiac rehabilitation present with highly heterogeneous ISWT values. Much of the variance in performance can be explained by patients’ age and sex. Comparing absolute values with age-and sex-specific reference values may aid interpretation of ISWT performance during initial patient assessment at entry to cardiac rehabilitation.

Background Exercise training is a key component of cardiac rehabilitation but there is a discrepancy between the high volume of exercise prescribed in trials comprising the evidence base and the lower volume prescribed to UK patients. Objective To quantify prescribed exercise volume and changes in cardiorespiratory fitness in UK cardiac rehabilitation patients. Methods We accessed n=950 patients who completed cardiac rehabilitation at four UK centres and extracted clinical data and details of cardiorespiratory fitness testing pre-and post-rehabilitation. We calculated mean and effect size (d) for change in fitness at each centre and converted values to metabolic equivalent (METs). We calculated a fixed-effects estimate of change in fitness expressed as METs and d. Results Patients completed 6 to 16 (median 8) supervised exercise sessions. Effect sizes for changes in fitness were d=0.34-0.99 in test-specific raw units and d=0.34-0.96 expressed as METs. The pooled fixed effect estimate for change in fitness was 0.52 METs (95% CI 0.51 to 0.53); or an effect size of d=0.59 (95% CI 0.58 to 0.60). Conclusion Gains in fitness varied by centre and fitness assessment protocol but the overall increase in fitness (0.52 METs) was only a third the mean estimate reported in a recent systematic review (1.55 METs). The starkest difference in clinical practice in the UK centres we sampled and the trials which comprise the evidence-base for cardiac rehabilitation was the small volume of exercise completed by UK patients. The exercise training volume prescribed was also only a third that reported in most international studies. If representative of UK services, these low training volumes and small increases in cardiorespiratory fitness may partially explain the reported inefficacy of UK cardiac rehabilitation to reduce patient mortality and morbidity.

We studied the effect of exercise-induced ischemia on high-resolution body surface potential maps in the depolarization interval. In particular our aim was to evaluate the effectiveness of selected nine ECG parameters in diagnostics of ischemic heart disease (IHD). The study group consisted of 123 subjects. The distributions of ECG signals averaged in time at rest and at peak exercise were compared. It was observed that for patients with IHD, averaged decreases of QRS amplitude at peak exercise were higher than in the control group and in the group of patients without IHD. IHD was associated also with enlargement of the area on the thorax surface where the decrease in the amplitude and increase in shape changes of the QRS complex were observed. The most effective parameters for the separation of patients with IHD were quantifiers of QRS shape changes. The use of an optimized ECG electrode layout improves the diagnostic value of QRS morphology descriptors.

ABSTRACT We conducted a pilot study to evaluate the safety of the shuttle walking test (SWT) and exercise training for cardiac patients in community-based cardiac rehabilitation settings. Overall, 33 cardiac patients were tested (19 males and 14 females, 67 ± 8 years). Eleven cardiac patients (testing group) and 22 cardiac patients (training group) underwent ambulatory electrocardiogram (ECG) monitoring during the SWT and exercise training during a long-term cardiac rehabilitation programme. Frequency of ECG events was reported for the two groups. Chi-square test was performed to determine associations between the incidence of cardiovascular events and poor functional capacity (SWT &amp;lt;450 m). The findings showed only minor events provoked during the SWT or exercise training, and no event-related hospitalisation, syncope episodes or fatality. The most important cardiac event was silent myocardial ischaemia (testing group: 27.3%; training group: 18%). Poor functional capacity was not associated with the risk of a cardiac event during exercise (testing group: χ2=0, p=0.99, phi=0.24; training group: χ2=2.1, p=0.15, phi=–0.42). In conclusion, supervised exercise testing and training are accompanied only by minor cardiovascular events and they can be carried out safely in community-based cardiac rehabilitation settings.

The incremental shuttle walk test (ISWT) is used to assess functional capacity of patients entering cardiac rehabilitation. Factors such as age and sex account for a proportion of the variance in test performance in healthy individuals but there are no reference values for patients with cardiovascular disease. The aim of this study was to produce reference values for the ISWT. Participants were n = 548 patients referred to outpatient cardiac rehabilitation who underwent a clinical examination and performed the ISWT. We used regression to identify predictors of performance and produced centile values using the generalised additive model for location, scale and shape model. Men walked significantly further than women (395 ± 165 vs. 269 ± 118 m; t = 9.5, P &lt; 0.001) so data were analysed separately by sex. Age (years) was the strongest predictor of performance in men (β = -5.9; 95% CI: -7.1 to -4.6 m) and women (β = -4.8; 95% CI: -6.3 to 3.3). Centile curves demonstrated a broadly li...