Metabolic Equivalents of Safe Physical Activity Levels at Anaerobic Threshold in Anorexia Nervosa Patients

Purpose Patients with anorexia nervosa (AN) require appropriate nutrient therapy and physical activity management. Eating disorder treatment guidelines do not include safe, evidence-based intensity criteria for exercise. This study used cardiopulmonary exercise testing (CPX) to evaluate the exercise tolerance of patients with AN and develop treatment guidelines to optimize their physical activity. Methods CPX was done with 14 female AN patients admitted to a specialized eating disorder unit between 2015 and 2019. Their anaerobic threshold (AT) was determined by assessing their exercise tolerance using CPX and compared with 14 healthy controls (HC). The metabolic equivalents (AT-METS) were compared when AT was reached. We examined factors related to AT (AN-AT) in the AN group, including age, body mass index (BMI), previous lowest weight, minimum BMI, past duration of BMI < 15, exercise history, and ΔHR (heart rate at the AT - resting heart rate). Results The AT of the AN group (BMI: 15.7 [Mean] ± 1.8 [SD]) was significantly lower than the HC group (BMI: 19.7 ± 1.8) (AN: 10.0 ± 1.8 vs HC: 15.2 ± 3.0 ml/kg/min, P<0.001). AT-METS was also significantly lower in the AN than the HC group (AN: 2.9 ± 0.52 vs HC: 4.4 ± 0.91, P<0.001). AN-AT was highly influenced by ΔHR. Conclusion The AT-METS level for these AN patients was 2.5-3.3 METS, and this index can be used by clinicians to teach AN patients a safe exercise intensity. CPX and AT-METS are useful tools for clinicians to manage physical activity in AN patients. Level of evidence III: Evidence obtained from case-control analytic studies

A Personal Biography of a Physiological Misnomer: The Anaerobic Threshold

In 1973 Wasserman, Whipp, Koyal, and Beaver published a groundbreaking study titled “Anaerobic threshold and respiratory gas analysis during exercise”. At that time, respiratory gas analysis and laboratory computers had evolved such that more advanced respiratory exercise physiology studies were possible. The initial publications from this group on the onset of anaerobic metabolism in cardiac patients, the first breath-by-breath VO2 system, the first description of the anaerobic threshold, and then later new methods to detect the anaerobic threshold have been and continue to be highly cited. In fact, their 1973 anaerobic threshold paper is the sixth and their 1986 paper is the second most cited paper ever published in the Journal of Applied Physiology. The anaerobic threshold concept has also generated>5500 publications with the rates increasing over time. The publication of two papers that help to refute the “anaerobic” explanation for this phenomenon had no effect on the rates of citations of the original anaerobic threshold papers or the number of anaerobic threshold papers published since. Thus, despite now substantial evidence refuting the proposed anaerobic mechanisms underlying this phenomenon, these papers continue to be highly influential in the discipline of exercise physiology and, perhaps even more explicitly, clinical exercise physiology.

Assessment of Tug of War pullers competition intensity and physiological response at the 2019 European Championship

Tug of war (TOW) involves 2 teams of eight people, pulling against each other on a rope. The main goal of TOW is to pull the opposing team towards a centre line over a distance of 4 m. The measurement of physiological parameters is key to understanding the demands of an activity and to identifying its limiting performance factors. The main aim of this study was to evaluate the intensity and effort demands of TOW pullers during competition, as follows: Data were collected from 7 male pullers (Height: 175.14±4.85; Body Mass: 77.39±3.92; Age: 39.86±11.68; %Fat: 17.56±5.21; VO2max: 44.24±8.38) in the 560 kg category. The blood lactate concentrations (LAC) were assessed before and at the end of each pull, and the global rating of perceived exertion (RPE) at the end of the pulls. The following week, pullers performed a graded exercise test (GXT). Heart rate, LAC and RPE were assessed before, during and at the end of the GXT to calculate the individual anaerobic threshold. The mean blood lactate concentrations recorded at the end of the pulls (6±1.9 mmol/l) were 32% higher than the mean values recorded for the individual anaerobic threshold intensity (4.1±0.5 mmol/l). For their part, the mean RPE values of athletes after the pulls (6±1.5 mmol/l) were 21% lower than those obtained for intensity of the individual anaerobic threshold (7.6±0.8 mmol/l). The intensity and effort response are greater and kept above the anaerobic threshold during the competition in TOW pullers. Resumen. Tug of war (TOW) involucra a 2 equipos de ocho personas, tirando una contra la otra con una cuerda. El objetivo principal es llevar al equipo contrario hacia una línea central a una distancia de 4 m. La medición de parámetros fisiológicos es clave para comprender las demandas de una actividad y para identificar sus factores limitantes de rendimiento. El objetivo principal de este estudio fue evaluar la intensidad y las demandas de esfuerzo de los tiradores de TOW durante la competición. 7 tiradores masculinos (altura: 175,14 ± 4,85; masa corporal: 77,39 ± 3,92; edad: 39,86 ± 11,68; % de grasa: 17,56 ± 5,21; VO2max: 44,24 ± 8,38) en la categoría de 560 kg. Se evaluaron concentraciones de lactato (LAC) antes y después de cada tirada, y el esfuerzo percibido (RPE) al final. La siguiente semana, los tiradores realizaron una prueba de esfuerzo (GXT). La FC, LAC y RPE se evaluaron antes, durante y después del GXT para calcular el umbral anaeróbico individual. Las concentraciones de LAC registradas medios registrados para la intensidad del umbral anaeróbico individual (VT2) (4,1 ± 0,5 mmol/l). Los valores medios de RPE de los deportistas en competición (6 ± 1,5 mmol/l) fueron un 21% inferiores a los obtenidos para la intensidad del VT2 (7,6 ± 0,8 mmol/l). La intensidad y la respuesta al esfuerzo son mayores y se mantienen por encima del VT2 durante la competición en tiradores TOW al final de los tirones (6 ± 1,9 mmol/l) fueron un 32% más altas que los valores.

Preoperative cardiopulmonary exercise testing for risk assessment before elective coronary artery bypass grafting surgery

Objective: To evaluate the feasibility and results of performing cardiopulmonary exercise test (CPET) in coronary artery disease (CAD) patients before elective coronary artery bypass grafting surgery (CABG). CPET has been increasingly employed in the evaluation of preoperative risk before noncardiac surgeries, but is still underutilized before cardiac surgery and may be useful, as clinical risk scores for preoperative assessment before cardiac surgeries have several limitations. Methods: Patients with CAD underwent CPET within 1 week before CABG. Oxygen consumption, oxygen pulse, oxygen consumption at the anaerobic threshold, minute ventilation/carbon dioxide relationship slope (VE/VCO2 slope), oxygen uptake efficiency slope (OUES) and heart rate recovery (HRR) were analyzed. The occurrence of complications during the test was recorded. Results: Twenty-eight patients (75% men), aged 61 (8) years, underwent preoperative CPET. There were no complications during CPET, even though 71.4% were interrupted by signs or symptoms of ischemia, and only 57% of the patients reached the anaerobic threshold. Conclusions: Preoperative CPET before elective CABG was feasible and safe. However, a large proportion of patients did not achieve the anaerobic threshold. Therefore, VE/VCO2 slope, OUES and HRR may be the most useful CPET variables in the preoperative period. Key words: coronary artery disease, coronary artery bypass grafting, cardiopulmonary exercise test, preoperative assessment

Effect of early cardiac rehabilitation on prognosis in patients with heart failure following acute myocardial infarction

Objective The purpose of this retrospective study is to evaluate the effectiveness of early cardiac rehabilitation on patients with heart failure following acute myocardial infarction. Methods Two hundred and thirty-two patients who developed heart failure following acute myocardial infarction were enrolled in this study. Patients were divided into heart failure with reduced ejection fraction group (n = 54) and heart failure with mid-range ejection fraction group (n = 178). Seventy-eight patients who accepted a two-week cardiac rehabilitation were further divided into two subgroups based on major adverse cardiovascular events. Key cardio-pulmonary exercise testing indicators that may affect the prognosis were identified among the cardiac rehabilitation patients. Results Early cardiac rehabilitation significantly reduced cardiac death and re-hospitalization in patients. There was more incidence of diabetes, hyperkalemia and low PETCO2 in the cardiac rehabilitation group who developed re-hospitalization. Low PETCO2 at anaerobic threshold (≤ 33.5 mmHg) was an independent risk factor for re-hospitalization. Conclusions Early cardiac rehabilitation reduced major cardiac events in patients with heart failure following acute myocardial infarction. The lower PETCO2 at anaerobic threshold is an independent risk factor for re-hospitalization, and could be used as a evaluating hallmark for early cardiac rehabilitation.

Relationships between parameters of cardiorespiratory function and bioimpedance analysis in young patients with type 1 diabetes mellitus

Type 1 diabetes mellitus (T1DM) triggers disruption of oxygen transport system in patients. The maximum oxygen consumption (VO2 max) during spiroergometry depends on the functional capabilities and composition of the body. Moreover, VO2 max may be considered a predictor of pathological changes in cardiovascular system.Aim. The purpose of the study was to investigate the compositional body characteristics and functional cardiorespiratory parameters in T1DM patients.Material and Methods. The study comprised 30 patients with T1DM (average age of 25.5 ± 8.1 years) and 10 patients of control group (average age of 27 ± 9 years). Patients received spiroergometry examination according to B. Bruce protocol and bioimpedansometry using the Inbody 770 apparatus. The study showed that T1DM patients reached anaerobic threshold faster (p = 0.032) and had significantly lower VO2 max and carbon dioxide emission compared to patients without diabetes (p = 0.021; p = 0.034) whereas exercise tolerance did not significantly differ compared with the corresponding value in control group. Patients with higher muscle mass i.e. muscle tissue weight (kg) according to bioimpedance measurements had higher values of VO2 max (L) in control group (p = 0.017) and in group of T1DM patients (p = 0.028).Conclusions: Young T1DM patients without cardiovascular diseases had significantly less effective cardiorespiratory system compared with that in people without diabetes even in those with high exercise tolerance. Rapid achievement of anaerobic threshold with preserved performance efficiency was a sign of unfavorable prognosis. Body mass index and lean body mass did not significantly affect the performance parameters in young T1DM patients. Screening of spiroergometry parameters may be used for identification of young T1DM patients at high risk of unfavorable cardiovascular diseases including chronic heart failure.

Prolonged Sojourn at Very High Altitude Decreases Sea-Level Anaerobic Performance, Anaerobic Threshold, and Fat Mass

Background: The influence of high altitude on an organism’s physiology depends on the length and the level of hypoxic exposure it experiences. This study aimed to determine the effect of a prolonged sojourn at very high altitudes (above 3,500m) on subsequent sea-level physical performance, body weight, body composition, and hematological parameters.Materials and Methods: Ten alpinists, nine males and one female, with a mean age of 27±4years, participated in the study. All had been on mountaineering expeditions to 7,000m peaks, where they spent 30±1days above 3,500m with their average sojourn at 4,900±60m. Their aerobic and anaerobic performance, body weight, body composition, and hematological parameters were examined at an altitude of 100m within 7days before the expeditions and 7days after they descended below 3,500m.Results: We found a significant (p&lt;0.01) decrease in maximal anaerobic power (MAPWAnT) from 9.9±1.3 to 9.2±1.3W·kg−1, total anaerobic work from 248.1±23.8 to 228.1±20.1J·kg−1, anaerobic threshold from 39.3±8.0 to 27.8±5.6 mlO2·kg−1·min−1, body fat mass from 14.0±3.1 to 11.5±3.3%, and a significant increase (p&lt;0.05) in maximal tidal volume from 3.2 [3.0–3.2] to 3.5 [3.3–3.9] L after their sojourn at very high attitude. We found no significant changes in maximal aerobic power, maximal oxygen uptake, body weight, fat-free mass, total body water, hemoglobin, and hematocrit.Conclusion: A month-long exposure to very high altitude led to impaired sea-level anaerobic performance and anaerobic threshold, increased maximal tidal volume, and depleted body fat mass, but had no effect on maximal aerobic power, maximal oxygen uptake, or hemoglobin and hematocrit levels.

Determinants of oxygen uptake and prognostic factors in cardiopulmonary exercise test in patients with Fontan surgery

Introduction: Cardiopulmonary exercise test (CPET) allows quantification of functional capacity of patients with Fontan. The objective of this study was to determine the role of CPET parameters in predicting a higher maximum oxygen consumption (VO2 max) and to analyse the role of CPET parameters in predicting an unfavourable outcome. Methods: A retrospective, cross-sectional, descriptive study was carried out on 57 patients with Fontan, who had undergone incremental CPET with cycloergometer between 2010 and 2020. Determinants of VO2 max and determinants of clinical deterioration were analysed. Results: In the univariate analysis, the variables significantly related to VO2 max were: age, sex, body mass index (BMI), years of Fontan evolution, intracardiac Fontan, oxygen consumption at anaerobic threshold (VO2AT), CO2 equivalents at anaerobic threshold (VE/VCO2) and chronotropic insufficiency. The multiple linear regression model that best fitted the relationship between VO2 max and independent variables (correlation coefficient 0.73) included sex (correlation index 3.35; p = 0.02), BMI (−0.27; p = 0.02), chronotropic failure (−2.79; p = 0.01) and VO2AT (0.92; p < 0.0001). In the univariate analysis of the prognostic CPET variables related to an unfavourable clinical situation, significance was only obtained with chronotropic insufficiency (p = 0.003). In multivariate analysis, chronotropic insufficiency maintains its association [p= 0.017, OR = 4.65 (1.3–16.5)]. Conclusions: In conclusion, together with the anthropometric parameters universally related to VO2 max, chronotropic insufficiency and VO2AT are the main determinants of functional capacity in patients with Fontan. Moreover, chronotropic insufficiency is closely related to unfavourable clinical evolution. Our data would support the intensive treatment of chronotropic insufficiency in order to improve the quality of life and the clinical situation of patients with Fontan.