Is inertial flywheel resistance training superior to gravity-dependent resistance training in improving muscle strength? A systematic review with meta-analyses

Objective

The primary aim of this systematic review was to determine if inertial flywheel resistance training is superior to gravity-dependent resistance training in improving muscle strength. The secondary aim was to determine whether inertial flywheel resistance training is superior to gravity-dependent resistance training in improving other muscular adaptations.

Ischemic strength training: a low‐load alternative to heavy resistance exercise?

Strength training with low loads in combination with vascular occlusion has been proposed as an alternative to heavy resistance exercise in the rehabilitation setting, especially when high forces acting upon the musculo-skeletal system are contraindicated. Several studies on low-to-moderate intensity resistance exercise combined with cuff occlusion have demonstrated increases in muscle strength and size that are comparable to those typically seen after conventional high-load strength training. However, the physiological mechanisms by which occlusion training induces increased muscle mass and strength are currently unclear, although several candidate stimuli have been proposed. Also, the long-term safety, practicality, and efficacy of this training method are still controversial. Furthermore, recent studies have demonstrated that in some instances, tourniquet cuffs may not be necessary for relative ischemia and significant training effects to occur with resistance exercise at low-to-moderate loads. The aims of the present review are to summarize current opinion and knowledge regarding the physiology of ischemic strength training and to discuss some of the training and health aspects of this type of exercise. In addition, suggestions for further research are given.     

Is responsiveness of elderly individuals to resistance training related to habitual nutritional intake? An exploratory analysis of a randomized controlled trial

Sport Sciences for Health - This study investigated the relationship between habitual nutritional intake and the responsiveness of elderly individuals to resistance training. Nineteen participants...     

Sea level and acute responses to hypoxia: do they predict physiological responses and acute mountain sickness at altitude?

OBJECTIVES: To compare a range of physiological responses to acute sea level hypoxia at simulated altitudes with the same physiological responses and acute mountain sickness (AMS) scores measured at altitude (similar to the simulated altitudes) during a 17 day trek in the Himalayas. METHODS: Twenty men and women aged 18-54 years took part in the study. End tidal CO(2) tension (PETCO(2)) and saturated oxygen (SaO(2)) were measured using a capnograph. Observations made at sea level and some simulated altitudes were compared with those in the Himalayas. Pairwise correlations were used to examine the correlation between variables and regression, with 95% prediction intervals providing information on how well one variable could be predicted from another for a given subject. RESULTS: There was only a significant correlation for a few comparisons. The 95% prediction intervals for individual SaO(2) values at a range of simulated altitudes were fairly wide going from +/- 4% to +/- 5%. All of the correlations between laboratory and Himalayan PETCO(2) values were not statistically significant. There was a significant correlation for the relation between SaO(2)and PETCO(2) at sea level for the laboratory data (r=-0.51; p=0.05). For the Himalayan data, there were significant correlations at Namche Bazaar (3450 m; day 3) (r=-0.56; p=0.01) and Dingboche (4300 m; day 6) (r=-0.48; p=0.03). The correlation between SaO(2) and PETCO(2) and AMS was generally poor. CONCLUSIONS: The results indicate that limited information can be gained on a subject's response to altitude by assessing physiological variables at sea level and a range of simulated altitudes before the subject carries out a trek at altitude.     

What makes champions? A review of the relative contribution of genes and training to sporting success

Elite sporting performance results from the combination of innumerable factors, which interact with one another in a poorly understood but complex manner to mould a talented athlete into a champion. Within the field of sports science, elite performance is understood to be the result of both training and genetic factors. However, the extent to which champions are born or made is a question that remains one of considerable interest, since it has implications for talent identification and management, as well as for how sporting federations allocate scarce resources towards the optimisation of high-performance programmes. The present review describes the contributions made by deliberate practice and genetic factors to the attainment of a high level of sporting performance. The authors conclude that although deliberate training and other environmental factors are critical for elite performance, they cannot by themselves produce an elite athlete. Rather, individual performance thresholds are determined by our genetic make-up, and training can be defined as the process by which genetic potential is realised. Although the specific details are currently unknown, the current scientific literature clearly indicates that both nurture and nature are involved in determining elite athletic performance. In conclusion, elite sporting performance is the result of the interaction between genetic and training factors, with the result that both talent identification and management systems to facilitate optimal training are crucial to sporting success.     

X-ray dose training: are we exposed to enough?

AIM: To study knowledge of radiation exposure among doctors of various grades and specialties in a large district general hospital. METHODS: A multiple-choice format questionnaire with a total of 11 questions was distributed amongst doctors at Derriford Hospital, Plymouth, UK. Doctors of various grades and specialties completed 240 questionnaires which tested knowledge of terrestrial and medical radiation exposure. RESULTS: With a pass mark of only 45% and a generous marking scheme, only 66 (27.5%) doctors passed. Only 15.4-25.8% of doctors knew the doses relative to a chest radiograph of various more complex procedures involving ionizing radiation and only 12.5% of doctors were aware of the one in 2000 risk of induction of fatal carcinoma from CT of the abdomen. Only 56.7% of practitioners who, under Ionizing Radiation (Medical Exposures) Regulations 2000, have responsibility for justifying procedures, passed the test. The proportion of practitioners correctly identifying the relative dose of a test to a chest radiograph varied from 30 to 56.7%, depending on the exam type. Only 20% in this group were aware of the risk of inducing a fatal cancer from a CT of the abdomen. CONCLUSION: The study demonstrated an urgent need to improve knowledge of radiation exposure amongst doctors in clinical practice.     

Risk factors for acute and overuse sport injuries in Swedish children 11 to 15 years old: What about resistance training with weights?

To determine the 1‐year self‐reported incidence of overuse and traumatic sport injuries and risk factors for injuries in children participating in a summer sports camp representing seven different sports. 4363 children, 11 to 15 years old participating in a summer camp in seven different sports answered a questionnaire. Injury in this cross‐sectional study was defined as a sport‐related trauma or overload leading to pain and dysfunction preventing the person from participation in training or competition for at least 1 week. A number of risk factors for injury were investigated such as sex, age, number of hours spent on training in general, and on resistance training with weights. Nearly half [49%, 95% confidence interval (CI) 48–51%] of the participants had been injured as a result of participation in a sport during the preceding year, significantly more boys than girls (53%, 95% CI 50–55% vs 46%, 95% CI 43–48%; P < 0.001). Three factors contributed to increased incidence of sport injuries: age, sex, and resistance training with weights. Time spent on resistance training with weights was significantly associated with sport injuries in a logistic regression analysis. In children age 11 to 15 years, the risk of having a sport‐related injury increased with age and occurred more often in boys than in girls. Weight training was the only modifiable risk factor that contributed to a significant increase in the incidence of sport injuries.     

Radiation-induced genomic instability and bystander effects: related inflammatory-type responses to radiation-induced stress and injury? A review

PURPOSE: To review studies of radiation responses in the haemopoietic system in the context of radiation-induced genomic instability, bystander effects and inflammatory-type processes. RESULTS: There is considerable evidence that cells that themselves are not exposed to ionizing radiation but are the progeny of cells irradiated many cell divisions previously may express a high frequency of gene mutations, chromosomal aberrations and cell death. These effects are collectively known as radiation-induced genomic instability. A second untargeted effect results in non-irradiated cells exhibiting responses typically associated with direct radiation exposure but occurs as a consequence of contact with irradiated cells or by receiving soluble signals from irradiated cells. These effects are collectively known as radiation-induced bystander effects. Reported effects include increases or decreases in damage-inducible and stress-related proteins; increases or decreases in reactive oxygen species, cell death or cell proliferation, and induction of mutations and chromosome aberrations. This array of responses is reminiscent of effects mediated by cytokines and other similar regulatory factors that may involve, but do not necessarily require, gap junction-mediated transfer, have multiple inducers and a variety of context-dependent consequences in different cell systems. That chromosomal instability in haemopoietic cells can be induced by an indirect bystander-type mechanism both in vitro and in vivo provides a potential link between these two untargeted effects and there are radiation responses in vivo consistent with the microenvironment contributing secondary cell damage as a consequence of an inflammatory-type response to radiation-induced injury. Intercellular signalling, production of cytokines and free radicals are features of inflammatory responses that have the potential for both bystander-mediated and persisting damage as well as for conferring a predisposition to malignancy. The induction of bystander effects and instabilities may reflect interrelated aspects of a non-specific inflammatory-type response to radiation-induced stress and injury and be involved in a variety of the pathological consequences of radiation exposures.     

Blood rheological responses to running and cycling: a potential effect on the arterial hypoxemia of highly trained athletes?

To investigate 1) the blood rheological responses to high training volume and 2) the potential effect of these responses on arterial hypoxemia induced during submaximal running and cycling, 10 triathletes performed an incremental cycle test, 20 minutes of running (R), and 20 minutes of cycling (C). All trials were performed at nearly 75 % of VO2max. Hematocrit (H), blood viscosity (etab), plasma viscosity (etapl), index of erythrocyte rigidity (Tk), changes in plasma volume (DeltaPV), pulmonary diffusing capacity (DLco), and arteriolized blood gas (PaO2) were measured before and after each trial. Pulse oxymetry (SpO2) and cardioventilatory data were collected continuously. A significant increase in etab, etapl, and H was noted after R and C with respect to pre-exercise, whereas DeltaPV decreased, with a greater decrease after C. Tk was significantly higher after R than after C. A significantly greater drop in DLco was noted after C compared with R. SpO2 decreased significantly more during R, as did PaO2. We conclude that blood rheological responses are specific to running and cycling. Cycling induced a sharp decrease in plasma volume, which could partially explain the greater DLco alteration. Running was characterized by an increase in Tk, which could be implicated in the severity of the drop in arterial oxygenation observed.     

Diagnostic performances of shear wave elastography: which parameter to use in differential diagnosis of solid breast masses?

Objective

To evaluate which shear wave elastography (SWE) parameter proves most accurate in the differential diagnosis of solid breast masses.

Methods

One hundred and fifty-six breast lesions in 139 consecutive women (mean age: 43.54?±?9.94 years, range 21–88 years), who had been scheduled for ultrasound-guided breast biopsy, were included. Conventional ultrasound and SWE were performed in all women before biopsy procedures. Ultrasound BI-RADS final assessment and SWE parameters were recorded. Diagnostic performance of each SWE parameter was calculated and compared with those obtained when applying cut-off values of previously published data. Performance of conventional ultrasound and ultrasound combined with each parameter was also compared.

Results

Of the 156 breast masses, 120 (76.9 %) were benign and 36 (23.1 %) malignant. Maximum stiffness (Emax) with a cut-off of 82.3 kPa had the highest area under the receiver operating characteristics curve (Az) value compared with other SWE parameters, 0.860 (sensitivity 88.9 %, specificity 77.5 %, accuracy 80.1 %). Az values of conventional ultrasound combined with each SWE parameter showed lower (but not significantly) values than with conventional ultrasound alone.

Conclusions

Maximum stiffness (82.3 kPa) provided the best diagnostic performance. However the overall diagnostic performance of ultrasound plus SWE was not significantly better than that of conventional ultrasound alone.

Key Points

? SWE offers new information over and above conventional breast ultrasound ? Various SWE parameters were explored regarding distinction between benign and malignant lesions ? An elasticity of 82.3 kPa appears optimal in differentiating solid breast masses ? However, ultrasound plus SWE was not significantly better than conventional ultrasound alone     

Man to man training: Can it help improve the diagnostic performances and interobserver variabilities of thyroid ultrasonography in residents?

Objective

The purpose of this study was to determine whether the man to man training can improve the diagnostic performances and interobserver variabilities of residents on thyroid ultrasonography.

Materials and methods

A set of 80 quiz cases with ultrasonography images of thyroid nodules (40 benign and 40 malignant on histopathology) were shown to the residents. Residents 1, 2, and 3 had not received the man to man training while Residents 4, 5, 6, and 7 had. The seven residents were asked to fill out one of the ultrasonography features (internal composition, echogenicity, margin, calcification, and shape) and the final assessment (probably benign and suspicious). Thyroid nodules with one or more ultrasonography features including marked hypoechogenicity, microlobulated or irregular margins, microcalcifications, and taller than wide shape were assessed as suspicious nodules. The diagnostic performances of US by the seven residents and interobserver variabilities between the seven residents and a faculty radiologist were calculated.

Results

The sensitivities, negative predictive values, and accuracies of Residents 4, 5, 6, and 7 were higher than those of Residents 1, 2, and 3. The final assessment between Residents 4, 5, 6, and 7 and the faculty radiologist showed almost perfect agreement but that between Residents 1, 2, and 3 and the faculty radiologist showed substantial agreement.

Conclusion

The man to man training is crucial for the residents to show better diagnostic performances and improvement of interobserver variabilities for evaluating thyroid nodules with ultrasonography.