Aplicaciones de la termografía infrarroja en el deporte. Una revisión / Applications of infrared thermography in sports. A review

La termografía infrarroja (TI) registra el calor irradiado de un cuerpo, que es emitido en un rango del espectro electromagnético que la visión humana no es capaz de identificar. La respuesta térmica depende de una serie de ajustes fisiológicos específicos como la homeostasis corporal y salud del deportista, lo cual permite establecer interesantes aplicaciones en el deporte. El objetivo de este trabajo ha sido revisar la literatura en torno a las aplicaciones de la TI en el ámbito del deporte, y proponer las características óptimas del registro en relación al evaluado, las condiciones ambientales y la cámara utilizada. Concluimos que la principal contribución de la TI en el ámbito del deporte es ayudar a identificar signos de lesión antes de que la lesión se produzca, permitiéndonos actuar de manera preventiva durante el proceso de entrenamiento (AU)

Infrared thermography (IRT) records the radiant heat of a body, which is emitted in the range of the electromagnetic spectrum that human vision is not able to identify. The thermal response depends on a number of specific physiological adjustments as body homeostasis and athlete’s health, which allow us to establishing interesting applications in sport. The aim of this study was to review the literature on IRT applications in sports, and to propose the optimal characteristics of the register in terms of the subject, the environmental conditions and the camera used. We conclude that the main contribution of IRT in the field of sport is to help identify signs of injury before it occurs, allowing us to act proactively along the training process (AU)

A single resistance exercise session improves myocardial contractility in spontaneously hypertensive rats

Resistance training evokes myocardial adaptation; however, the effects of a single resistance exercise session on cardiac performance are poorly understood or investigated. This study aimed to investigate the effects of a single resistance exercise session on the myocardial contractility of spontaneously hypertensive rats (SHRs). Male 3-month-old SHRs were divided into two groups: control (Ct) and exercise (Ex). Control animals were submitted to sham exercise. Blood pressure was measured in conscious rats before the exercise session to confirm the presence of arterial hypertension. Ten minutes after the exercise session, the animals were anesthetized and killed, and the hearts were removed. Cardiac contractility was evaluated in the whole heart by the Langendorff technique and by isometric contractions of isolated left ventricular papillary muscles. SERCA2a, phospholamban (PLB), and phosphorylated PLB expression were investigated by Western blot. Exercise increased force development of isolated papillary muscles (Ex=1.0±0.1 g/mg vs Ct=0.63±0.2 g/mg, P<0.05). Post-rest contraction was greater in the exercised animals (Ex=4.1±0.4% vs Ct=1.7±0.2%, P<0.05). Papillary muscles of exercised animals developed greater force under increasing isoproterenol concentrations (P<0.05). In the isolated heart, exercise increased left ventricular isovolumetric systolic pressure (LVISP; Δ +39 mmHg; P<0.05) from baseline conditions. Hearts from the exercised rats presented a greater response to increasing diastolic pressure. Positive inotropic intervention to calcium and isoproterenol resulted in greater LVISP in exercised animals (P<0.05). The results demonstrated that a single resistance exercise session improved myocardial contractility in SHRs.

Acute exposure to lead increases myocardial contractility independent of hypertension development

We studied the effects of the acute administration of small doses of lead over time on hemodynamic parameters in anesthetized rats to determine if myocardial contractility changes are dependent or not on the development of hypertension. Male Wistar rats received 320 µg/kg lead acetate iv once, and their hemodynamic parameters were measured for 2 h. Cardiac contractility was evaluated in vitro using left ventricular papillary muscles as were Na+,K+-ATPase and myosin Ca2+-ATPase activities. Lead increased left- (control: 112 ± 3.7 vs lead: 129 ± 3.2 mmHg) and right-ventricular systolic pressures (control: 28 ± 1.2 vs lead: 34 ± 1.2 mmHg) significantly without modifying heart rate. Papillary muscles were exposed to 8 µM lead acetate and evaluated 60 min later. Isometric contractions increased (control: 0.546 ± 0.07 vs lead: 0.608 ± 0.06 g/mg) and time to peak tension decreased (control: 268 ± 13 vs lead: 227 ± 5.58 ms), but relaxation time was unchanged. Post-pause potentiation was similar between groups (n = 6 per group), suggesting no change in sarcoplasmic reticulum activity, evaluated indirectly by this protocol. After 1-h exposure to lead acetate, the papillary muscles became hyperactive in response to a β-adrenergic agonist (10 µM isoproterenol). In addition, post-rest contractions decreased, suggesting a reduction in sarcolemmal calcium influx. The heart samples treated with 8 µM lead acetate presented increased Na+,K+-ATPase (approximately 140%, P < 0.05 for control vs lead) and myosin ATPase (approximately 30%, P < 0.05 for control vs lead) activity. Our results indicated that acute exposure to low lead concentrations produces direct positive inotropic and lusitropic effects on myocardial contractility and increases the right and left ventricular systolic pressure, thus potentially contributing to the early development of hypertension.

Efeito da ingestão de taurina no desempenho físico: uma revisão sistemática / Effect of taurine intake on physical performance: a systematic review

Objetivo. Presentar los efectos de la taurina (Tau) en la capacidad aeróbica y anaeróbica, además de describir sus mecanismos de acción. Método. Se ha realizado una revisión sistemática de la literatura en las bases de datos PubMed/Medline y SportDiscus, teniendo como criterios de inclusión estudios con humanos, publicados en lengua inglesa, entre el 1 de enero de 2000 hasta el 1 de septiembre de 2011. La manera de consumo de Tau fue: Tau aislada o como ingrediente de bebidas energéticas evaluada con un suplemento placebo. La calidad de los estudios seleccionados fue valorada por la escala de PEDro siendo considerados los artículos con puntuaciones por encima de 5. Resultados. Fueron seleccionados 14 estudios, siendo 11 los que obtuvieron cambios en la capacidad física aeróbica y 3 en la anaeróbica. Se observaron mejoras significativas en las actividades aeróbicas (8 de los 11 artículos) de igual manera que en las anaeróbicas (2 de los 3 estudios) tras ingesta de Tau frente a placebo. Conclusión. El consumo agudo de apenas 1 g de Tau, independiente del tiempo previo de ingesta presentó un efecto positivo frente la capacidad física aeróbica y anaeróbica. El principal efecto ergogénico que se observó en el componente aerobio fue aumentar la capacidad temporal para realizar un ejercicio, sin embargo en la actividad anaerobia proporcionó una mejora en la respuesta de los iones de calcio durante la contracción muscular(AU)

Objective. Describe the effects of taurine (Tau) on aerobic and anaerobic physical performance as well as its mechanisms of action. Method. A systematic literature review on PubMed/Medline and SPORTDiscus was performed, including studies on humans which were published in English between January 1st, 2000 and September 1st, 2011.The forms of Tau intake were as the isolated compound (Tau) or as an ingredient in energy drinks analyzed with a placebo supplement. The quality of the selected articles was assessed using the PEDro scale and included articles with at least 5 points. Results. After the filtering process, 14 studies were selected from which 11 presented changes in aerobic physical performance and 3 in anaerobic physical performance. Significant improvements were observed in aerobic activities (8 out of 11 articles) and in anaerobic activities (2 out of 3 studies) after intake of Tau, compared to the placebo. Conclusion. The consumption of only 1 g of Tau, regardless of the time prior to intake, showed a beneficial effect on aerobic and anaerobic physical performance. The main ergogenic effect observed in the aerobic component was an increase on the temporal capacity of performing an exercise, whereas for the anaerobic activity there was a better response of calcium ions during muscle contraction(AU)

Avaliação da temperatura da pele durante o exercício através da termografia infravermelha: uma revisão sistemática / Evaluation of skin temperature during exercise by infrared thermography: a systematic review

Objetivo. Describir los cambios en la temperatura de la piel (Tp) durante el ejercicio registrado por medio de termografía infrarroja. Método. Se realizó una revisión sistemática de la literatura utilizando los términos ejercicio y termografía en las bases de datos de MEDLINE/PubMed, IEEEXplore y SciELO teniendo como principales factores de inclusión, estudios con humanos sin ningún tipo de problema físico o metabólico. Resultados. Tras el proceso de exclusión, fueron seleccionados ocho artículos. La Tp tiende a disminuir al inicio del ejercicio, de manera que su magnitud depende de la duración e intensidad de la actividad propuesta. En ejercicios con carga progresiva se observa una continua reducción de la Tp en comparación con los valores de reposo. Sin embargo, en ejercicios prolongados, la Tp puede variar según la región corporal evaluada con reducción, mantenimiento o incluso un aumento térmico, como sucede en las principales regiones musculares involucradas en el ejercicio. La Tp presenta respuestas específicas durante el ejercicio en función de la región corporal y la necesidad de pérdida de calor. Conclusión. La Tp disminuye en la fase inicial del ejercicio. La manera de realizar el ejercicio de perfil máximo o submáximo determina la respuesta de la Tp. No existe una respuesta homogénea en la Tp entre las diferentes regiones corporales, demostrando así la extremada complejidad del proceso de control de la temperatura central. Consecuentemente, la termografía infrarroja puede ser un valioso instrumento para hacer un seguimiento tanto de la respuesta térmica local como de la general(AU)

Objective. To describe the changes on Skin Temperature (Tsk) during exercise through Infrared Thermography. Method. A systematic review of the current literature was made, using the keywords "exercise" and "thermography" on the database MEDLINE/PubMed, IEEEXplore and SciELO. The research was made including the articles done with healthy humans without any physical or metabolic impairment. Results. After the exclusion process eight articles were selected. Tsk was has the tendency to decrease at the beginning of the exercise, depending on the duration and intensity of the task. In graded exercises a continuous reduction on Tsk was observed. Nevertheless, a bigger duration could lead to different thermal responses depending on the body area: reduction, maintenance or even an increase on the main regions involved on the exercise. Tsk has specific thermal responses depending on the body region and the heat loss necessities. Conclusion. Tsk decreases during the early stages of exercise. The thermal response will depend on the way of doing the maximal or submaximal exercise. There is a heterogeneous thermal response of Tsk between the different body regions, showing the extremely complexity of body temperature control. Therefore, Infrared Thermography could be a valuable tool in order to monitor both the local or the main thermal responses(AU)

Propagação vegetativa de espécies silvestres do gênero Piper, com potencial para uso como porta enxertos em pimenta-do-reino (Piper nigrun) / Vegetative propagation of wild species of the genus Piper, with potential for use as rootstocks in black pepper (Piper nigrun)

O estabelecimento de espécies usadas como porta-enxerto, importantes na olericultura, podem ser multiplicadas por meio da estaquia com auxílio de fitorreguladores. Objetivou-se com este trabalho avaliar a influência do AIB no estabelecimento de espécies nativas do gênero Piper com potencial de uso como porta-enxerto de Piper nigrum. Estacas de P. Arboreum, P. amplum e P. sp foram submetidas a diferentes dosagens de AIB (0, 2000, 4000, 6000 e 8000 mg.L-1) e mantidas em estufa agrícola com irrigação intermitente com temperatura e umidade controlados. O delineamento experimental utilizado foi inteiramente casualizado em esquema fatorial 3x5 (3 espécies de Piper x 5 dosagens de AIB) e composto por 3 repetições por tratamento, sendo cada parcela composta por 10 estacas. A avaliação foi realizada aos 45 dias de transplantio e as variáveis analisadas foram: índice de sobrevivência, número médio de folhas, número médio de brotos e comprimento médio do maior broto. A espécie Piper arboreum apresentou bons resultados referentes ao crescimento da parte aérea independentemente da concentração de AIB empregada.

The establishment of species used as rootstock, which are important in horticulture crop scan may be multiplied, with the aid of growth regulators, by cutting. The objective of this study was to evaluate the influence of IBA on the establishment of native species of the genus Piper with potential use as rootstock of Piper nigrum. Cuttings of P. arboreum, P. amplum and P. sp were treated with different concentrations of IBA (0 ,2000, 4000, 6000 and 8000mg.L-1) and maintained in a greenhouse with intermittent irrigation, with the temperature and humidity controlled. The experimental design was completely randomized in a factorial 3x5 plan (3 Piper species x5 doses of IBA) and comprising of three repetitions per treatment, each plot consisting of 10 cuttings. The evaluation was performed at 45 days of transplanting and the analyzed variables were: survival rate, the number of leaves, the number of shoots and the length of the largest shoot. The Piper arboretum species showed the best growth results for the aerial part independent of the IBA concentration used.