Effects of age, sex, sweat rate and environmental conditions on heart rate and perceived exertion in indoor cycling.

pre-print206 K

Hepcidin Response to Exercise: A Review.

Given the multiple functions of iron in the body, any state of iron deficiency will induce a series of secondary effects that could compromise sports performance. Low serum iron levels are commonly observed in athletes during the course of a training period, especially in those performing aerobic exercises and resistance training. Sometimes, body iron levels will even fall below those detected in sedentary individuals, and we could go as far as to say that iron deficiency is the most frequently observed nutrition disorder among athletes of any sport. Hepcidin, a hormone secreted by hepatocytes whose principal mechanism of action is the degradation of ferroportin (the main iron exporter from macrophages and the basolateral membrane of duodenal enterocytes), has been proposed as the main regulator of the body’s iron reserves. Thus, elevated serum hepcidin levels lead to diminished iron absorption and recycling, while lower levels of the hormone will cause greater iron absorption. Among the factors that affect the hepcidin response produced, we should highlight an individual’s total iron levels, erythropoietic demands, state of hypoxia, dietary iron, inflammation and physical exercise. Given the important role played by iron regulatory mechanisms in physical performance, this report reviews our current understanding of the physiological response of hepcidin to different sports intensities and modalities.post-print98 K

Heart rate recovery normality data recorded in response to a maximal exercise test in physically active men.

Background. Despite a growing clinical interest in determining the heart rate recovery (HRR) response to exercise, the limits of a normal HRR have not yet been well established. Purpose. This study was designed to examine HRR following a controlled maximal exercise test in healthy, physically active adult men. Methods. The subjects recruited (n=789) performed a maximal stress test on a treadmill. HRR indices were calculated by subtracting the 1st and 3rd minute heart rates during recovery from the maximal heart rate obtained during stress testing and designated these as HRR-1 and HRR-3, respectively. The relative change in HRR was determined as the decrease in HR produced at the time points 1 min and 3 min after exercise as a percentage of the peak HR (%HRR-1/HRpeak and %HRR-3/HRpeak, respectively). Percentile values of HRR-1 and HRR-3 were generated for the study population. Results. Mean HHR-1 and HHR-3 were 15.24±8.36 bpm and 64.58±12.17 bpm, respectively and %HRR-1/HRpeak and %HRR-3/HRpeak were 8.60±4.70% and 36.35±6.79%, respectively. Significant correlation was detected between Peak VO2 and HRR-3 (r=0.36; p<0.001) or %HRR-3/HRpeak (r=0.23; p<0.001). Conclusions. Our study provides normality data for heart rate recovery following a maximal ergometry test obtained in a large population of physically active men.pre-print166 K

Upper extremity deep vein thrombosis in a triathlete: Again intense endurance exercise as a thrombogenic risk.

Triathlon followers increase each year and long-distance events have seen major growth worldwide. In the cycling phase, athletes must maintain an aerodynamic posture on the bike for long periods of time. We report a case of a 38-year-old triathlete with symptoms of an axillary vein thrombosis 48 h after a long triathlon competition. After 3 days of hospitalizationwith a treatment consisted on enoxaparin anticoagulant and acenocumarol, the patient was discharged with instructions to continue treatment under home hospitalization with acetaminophen. Four weeks after the process, the patient was asymptomatic and the diameter of his armwas near normality. Due to the growing popularity of events based on endurance exercise, it is necessary more research to determine the etiopathogeny of deep venous thrombosis in athletes.pre-print274 K

Effects of beetroot juice intake on repeated performance of competitive swimmers.

Background: Beetroot juice is a sport supplement with a high level of evidence on the physical performance enhancement. However, in swimming, there is no clear data about the effects of beetroot juice on performance. Objective: To investigate whether an acute intake of beetroot juice (BJ) improves the performance of competitive swimmers in a repeated maximum swimming effort. Method: Thirteen national-level swimmers (six females and seven males), participated in this randomized, double-blind crossover study. In two different trials, swimmers ingested a 70-mL placebo shot (.04 mmol NO3−; PLA) or a 70-mL Beet-It shot (6.4 mmol of NO3−beet juice [BJ]) 3 h before undergoing a 6 × 100-m front-crawl maximal effort test with 7 min rest between each 100 m. Results: Overall, 100-m times showed no difference between the BJ and PLA groups (p = .364), although a possibly shorter time was observed for BJ in the last repetition (p = .104; mean difference [MD] = −.99 s, mean-based inference [MBI] = 49/51/0). Participants in the BJ condition showed a possibly lower rate of perceived exertion in the first (p = .242, MD = −.85, MBI = 70/28/2) and second repetitions (p = .165, MD = 1.15, MBI = 83/16/1), whereas Total Quality Recovery scale scores were likely higher in the first (p = .110, MD = 1.15, MBI = 83/16/1) and third (p = .082, MD = −.77, MBI = 70/29/1) repetitions compared with those in the PLA group. Blood lactate concentration [La+] levels showed no differences between groups in any of the repetitions (p > .05, unclear), and we observed an increase in 100-m times for both BJ and PLA (BJ: p = .014, MD = −1.51 s; PLA: p = .029, MD = −1.57 s) after the fifth repetition. Conclusion: No clear differences in performance were observed in a 6 × 100-m repeated sprint test by competitive swimmers when supplementing (or not) with BJ. However, there was a trend toward a better recovery between efforts and a better tolerance of fatigue when swimmers ingested BJ.post-print1,23 M

Efectos analgésicos del ejercicio físico en pacientes con dolor crónico musculoesquelético durante el confinamiento por la pandemia COVID-19.

Introducción: El confinamiento vivido durante la pandemia del COVID-19 en España durante más de dos meses, podría afectar severamente a la condición y calidad de vida de los pacientes que sufren dolor crónico musculoesquelético. Teniendo en cuenta los efectos analgésicos que el ejercicio físico puede generar, gran parte de la población ha realizado ejercicio físico en sus domicilios como mecanismo del control del dolor, durante este periodo. Objetivo: El objetivo de este estudio fue conocer el tipo y la dosis de ejercicio físico realizado, así como la percepción de los pacientes en la reducción del dolor, durante el periodo de confinamiento por el COVID-19. Material y método: Se realizó una encuesta ad hoc a través de Google Forms a 86 pacientes para conocer su estado, el tipo de ejercicio que realizaron y la cantidad de ejercicio, así como si habían percibido una reducción de su dolor durante el periodo de confinamiento. Resultados: La intensidad de dolor disminuyó de forma significativa (p=0,001) cuando se hizo algún tipo de ejercicio físico. El ejercicio de fuerza fue elegido por el 51% de la población de forma exclusiva, y las frecuencias y el tiempo de sesión no fueron diferentes de forma significativa entre los sujetos que sintieron una reducción del dolor y los que no. Conclusión: Una programación de ejercicio físico de 4 días a la semana, durante al menos 50 minutos y con intensidades del 77% de FCmax de ejercicio aeróbico o de fuerza sería recomendable en un paciente con dolor crónico, como estrategia para la reducción del dolor. Los resultados de nuestro estudio no aconsejan, para pacientes con dolor crónico, sesiones de terapia combinada, independientemente de la localización primaria del dolor.post-print118 K

Effects of high-intensity interval versus continuous exercise training on post-exercise heart rate recovery in coronary heart-disease patients.

Background: Heart rate recovery (HRR) has been considered a prognostic and mortality indicator in both healthy and coronary patients. Physical exercise prescription has shown improvements in VO2peak and HRR, but most of the studies have been carried out applying continuous training at a moderate intensity, being very limited the use of protocols of high intensity interval training in coronary patients. We aimed to compare the effects of a moderate continous training (MCT) versus a high intensity interval training (HIIT) programme on VO2 peak and HRR. Methods: Seventy three coronary patients were assigned to either HIIT or MCT groups for 8 weeks. Incremental exercise tests in a cycloergometer were performed to obtain VO2peak data and heart rate was monitored during and after the exercise test to obtain heart rate recovery data. Results: Both exercise programmes significantly increase VO2peak with a higher increase in the HIIT group (HIIT: 4.5± 4.46 ml/kg/min vs MCT: 2.46±3.57 ml/kg/min; P=0.039). High intensity interval training resulted in a significantly increase in HRR at the first and second minute of the recovery phase (15,44±7,04 vs 21,22 ±6,62, P <0,0001 and 23,73±9,64 vs 31,52±8,02, p <0,0001, respectively). Conclusions: The results of our research show that the application of HIIT to patients with chronic ischemic heart disease of low risk resulted in an improvement in VO2peak, and also improvements in post-exercise heart-rate recovery, compared with continuous training.pre-print792 K

Exercise Physiology at “Conversational Level” Is Not Impaired in Healthy Young Subjects Wearing Masks or Respirators.

Objective: The aim of this study was to evaluate the effects of the use of both surgical masks and FFP2 respirators on the inspiratory muscle strength, metabolic parameters, heart rate, subjective perceived exertion, and dyspnea perception, before and during 30 min stable load exercise at “conversational level”. Methods: A randomized cross-over study was carried out. Nineteen healthy adults completed 3 conditions (without a mask, with a surgical mask or an FFP2 respirator) during a 30-min steady-state test at the lactate threshold intensity. Inspiratory muscle strength was measured before and after the test, and metabolic parameters, heart rate, subjective perceived exertion, and dyspnea perception were collected at baseline, during, and after the test. Results: There was a significant reduction in inspiratory muscle strength after the 30-min test in all conditions (control: 6.26 mm Hg, p < 0.5; surgical mask: 8.55 mm Hg, p < 0.01; FFP2 respirator: 12.42 mm Hg, p < 0.001), but without significant differences between them (p = 0.283). Data showed a statistically significant effect for time, but did not show a statistically significant interaction between condition and time for heart rate (p = 0.674), oxygen saturation (p = 0.297), blood lactate level (p = 0.991), rating perceived exertion (p = 0.734) and dyspnea (p = 0.532) comparisons. Conclusions: The present study findings suggested that inspiratory muscle strength and physiological parameters during “conversational level” exercise were not impaired under wearing masks in healthy, nonsmoking young adults.pre-print319 K

Mechanical efficiency of high versus moderate intensity aerobic exercise in coronary heart disease patients: A randomized clinical trial

Background: Mechanical efficiency (ME) refers to the ability of an individual to transfer energy consumed by external work. A decreased ME, could represent an increased energy cost during exercise and may, therefore, be limited in terms of physical activity. This study aimed to compare the influence of two different exercise protocols: moderate continuous training (MCT) versus high intensity interval training (HIIT), as part of a cardiac rehabilitation program on ME values among coronary patients.  Methods: One hundred and ten coronary patients were assigned to either HIIT or MCT groups for 8 weeks. Incremental exercise tests in a cycle ergometer were performed to obtain VO2peak. Net energy expenditure (EE) and ME were obtained at intensities corresponding to the first (VT1) and second (VT2) ventilatory thresholds, and at VO2peak. Results: Both exercise programs significantly increase VO2peak with a higher increase in the HIIT group (2.96 ± 2.33 mL/kg/min vs. 3.88 ± 2.40 mL/kg/min, for patients of the MCT and HIIT groups, respectively, p &lt; 0.001). The ME at VO2peak and VT2 only significantly increased in the HIIT group. At VT1, ME significantly increased in both groups, with a greater increase in the HIIT group (2.20 ± ± 6.25% vs. 5.52 ± 5.53%, for patients of the MCT and HIIT groups, respectively, p &lt; 0.001).  Conclusions: The application of HIIT to patients with chronic ischemic heart disease of low risk re- sulted in a greater improvement in VO2peak and in ME at VT1, than when MCT was applied. Moreover, only the application of HIIT brought about a significant increase in ME at VT2 and at VO2peak.

Mechanical efficiency of high versus moderate intensity aerobic exercise in coronary heart disease patients: A randomized clinical trial.

Background: Mechanical efficiency (ME) refers to the ability of an individual to transfer energy consumed by external work. A decreased ME, could represent an increased energy cost during exercise and may, therefore, be limited in terms of physical activity. This study aimed to compare the influence of two different exercise protocols: moderate continuous training (MCT) versus high intensity interval training (HIIT), as part of a cardiac rehabilitation program on ME values among coronary patients. Methods: One hundred and ten coronary patients were assigned to either HIIT or MCT groups for 8 weeks. Incremental exercise tests in a cycle ergometer were performed to obtain VO2peak. Net energy expenditure (EE) and ME were obtained at intensities corresponding to the first (VT1) and second (VT2) ventilatory thresholds, and at VO2peak. Results: Both exercise programs significantly increase VO2peak with a higher increase in the HIIT group (2.96 ± 2.33 mL/kg/min vs. 3.88 ± 2.40 mL/kg/min, for patients of the MCT and HIIT groups, respectively, p < 0.001). The ME at VO2peak and VT2 only significantly increased in the HIIT group. At VT1, ME significantly increased in both groups, with a greater increase in the HIIT group (2.20 ± ± 6.25% vs. 5.52 ± 5.53%, for patients of the MCT and HIIT groups, respectively, p < 0.001). Conclusions: The application of HIIT to patients with chronic ischemic heart disease of low risk resulted in a greater improvement in VO2peak and in ME at VT1, than when MCT was applied. Moreover, only the application of HIIT brought about a significant increase in ME at VT2 and at VO2peak. (Cardiol J 2019; 26, 2: 130–137)post-print251 K