Laboratory-based Exercise Test Research Articles

Relationship Between Heart Rate and Perceived Exertion in Neuromuscular Diseases: How do Laboratory-Based Exercise Testing Results Translate to Home-Based Aerobic Training Sessions?

To examine the heart rate-perceived exertion relationship between maximal exercise testing and home-based aerobic training in neuromuscular diseases. Multicentre randomized controlled trial, intervention group data. Individuals with Charcot-Marie-Tooth disease (n = 17), post-polio syndrome (n = 7) or other neuromuscular diseases (n = 6). Participants followed a 4-month, homebased aerobic training programme guided by heart rate. Heart rate and ratings of perceived exertion (6-20 Borg Scale) were assessed for each minute during a maximal exercise test, and at the end of each exercise interval and recovery period during training. Heart rate and corresponding ratings of perceived exertion values of individual participants during training were visualized using plots, together with the exercise testing linear regression line between heart rate and ratings of perceived exertion. High correlation coefficients (i.e. > 0.70) were found between heart rate and ratings of perceived exertion, in all participants during testing (n = 30), and in 57% of the participants during training. Based on the plots the following distribution was found; participants reporting lower (n = 12), similar (n = 10), or higher (n = 8) ratings of perceived exertion values for corresponding heart rates during training compared with testing. Most participants had a different perception of effort for corresponding heart rates during training in comparison with exercise testing. Healthcare professionals should be aware that this may imply under- and over-training.

Heart rate and oxygen uptake kinetics obtained from continuous measurements with wearable devices during outdoor walks of patients with COPD.

Continuous physiological measurements during a laboratory-based exercise test can provide physiological biomarkers, such as heart rate (HR) and oxygen uptake (V̇O2) kinetics, that carry clinically relevant information. In contrast, it is not clear how continuous data generated by wearable devices during daily-life routines could provide meaningful biomarkers. We aimed to determine whether valid HR and V̇O2 kinetics can be obtained from measurements with wearable devices during outdoor walks in patients with chronic obstructive pulmonary disease (COPD). HR (Polar Belt) and V̇O2(METAMAX3B) were measured during 93 physical activity transitions performed by eight patients with COPD during three different outdoor walks (ntr = 77) and a 6-minute walk test (ntr = 16). HR and V̇O2 kinetics were calculated every time a participant started a walk, finished a walk or walked upstairs. HR and V̇O2 kinetics were considered valid if the response magnitude and model fit were adequate, and model parameters were reliable. Continuous measurements with wearable devices provided valid HR kinetics when COPD patients started or finished (range 63%-100%) the different outdoor walks and valid V̇O2 kinetics when they finished (range 63%-100%) an outdoor walk. The amount of valid kinetics and kinetic model performance was comparable between outdoor walks and a laboratory-based exercise test (p > .05). We envision that the presented approach could improve telemonitoring applications of patients with COPD by providing regular, unsupervised assessments of HR kinetics during daily-life routines. This could allow to early identify a decline in the patients' dynamic physiological functioning, physical fitness and/or health status.

AB105. SOH21AS259. An audit of routine pre-participation medical evaluation in athletes attending for laboratory-based exercise testing and a profile of endurance athletes in Ireland

Background: The pre-participation medical evaluation (PPE) of athletes prior to undergoing graded exercise testing is routine practice in the Trinity College Dublin human performance laboratory. The aim of this study was to compare data collected in 2017/18 with that of 2012/13, since the introduction of an updated PPE process and to build a profile of endurance athletes.

Activity restriction in mild COPD: a challenging clinical problem.

Dyspnea, exercise intolerance, and activity restriction are already apparent in mild chronic obstructive pulmonary disease (COPD). However, patients may not seek medical help until their symptoms become troublesome and persistent and significant respiratory impairment is already present; as a consequence, further sustained physical inactivity may contribute to disease progression. Ventilatory and gas exchange impairment, cardiac dysfunction, and skeletal muscle dysfunction are present to a variable degree in patients with mild COPD, and collectively may contribute to exercise intolerance. As such, there is increasing interest in evaluating exercise tolerance and physical activity in symptomatic patients with COPD who have mild airway obstruction, as defined by spirometry. Simple questionnaires, eg, the modified British Medical Research Council dyspnea scale and the COPD Assessment Test, or exercise tests, eg, the 6-minute or incremental and endurance exercise tests can be used to assess exercise performance and functional status. Pedometers and accelerometers are used to evaluate physical activity, and endurance tests (cycle or treadmill) using constant work rate protocols are used to assess the effects of interventions such as pulmonary rehabilitation. In addition, alternative outcome measurements, such as tests of small airway dysfunction and laboratory-based exercise tests, are used to measure the extent of physiological impairment in individuals with persistent dyspnea. This review describes the mechanisms of exercise limitation in patients with mild COPD and the interventions that can potentially improve exercise tolerance. Also discussed are the benefits of pulmonary rehabilitation and the potential role of pharmacologic treatment in symptomatic patients with mild COPD.

Comparison of Male and Female Road Cyclists under Identical Stage Race Conditions

To compare the demands of a 6-d stage race using field measures of power output and HR in male (n=8) and female (n=10) competitive cyclists. HR and power output were monitored in males and females competing in separate races on identical courses including a prolog (4 km), four circuit/road races (mean ± SD: 118 ± 23 km), and a criterium (47 km). All subjects participated in laboratory-based exercise testing within 2 wk of the race. Compared with females, males took 10%, 22%, and 10% less time to complete the prolog, circuit/road races, and criterium, respectively. For males, power output in the prolog, circuit/road races, and criterium averaged 405, 247, and 278 W, respectively. For females, power output averaged 295, 160, and 205 W, respectively. During the prolog, the percent time spent below, at, and above the lactate threshold was 29%, 9%, and 62%, respectively, for males and 24%, 7%, and 69%, respectively, for females. For the circuit/road races, these values were 57%, 10%, and 33%, respectively, for males and 62%, 10%, and 28%, respectively, for females. During the criterium, these values were 51%, 6%, and 43%, respectively, for males, and 50%, 8%, and 42%, respectively, for females. Although men had faster finishing times and higher absolute power outputs, no significant difference was found between men and women in their relative power response. These findings suggest that pacing strategy is based on relative exercise responses and not on absolute exercise responses.

Airway hyperresponsiveness and airway inflammation in elite swimmers

The prevalence of respiratory symptoms and airway hyperresponsiveness (AHR) is high in elite athletes; swimmers have one of the highest prevalences. No consensus exists on what airway challenge to use when identifying AHR in elite athletes. Further, knowledge is sparse about when during their active sport career AHR develops and if there is an acute effect on the airway inflammation of a swimming training session. We aimed to (i) evaluate the airway response to a methacholine challenge, a eucapnic voluntary hyperpnoea (EVH) test, a field-based exercise test (FBT) and a laboratory-based exercise test (LBT) in adult elite swimmers; (ii) investigate airway responsiveness and airway inflammation in adolescent elite swimmers; and (iii) evaluate the acute effect of a training session in an indoor swimming pool on airway inflammation in adolescent elite swimmers. Two groups were studied. (i) In adult elite swimmers (n = 16), we examined airway response in four airway provocation tests: methacholine challenge, EVH test, FBT and LBT. (ii) In adolescent elite swimmers (n = 33), we examined airway responsiveness to EVH and methacholine, and airway inflammation and compared the findings with those in asthmatic adolescents (n = 32) and unselected adolescents (n = 35). Further, we examined the acute effect of swimming on airway inflammation in a subpopulation of the adolescent swimmers (n = 21). Airway inflammation was evaluated using sputum induction, measurements of exhaled nitric oxide (FeNO) and exhaled breath condensate (EBC). Of 16 adult swimmers, eight (50%) had AHR; five of the eight (63%) were identified with the EVH test, four (50%) with the FBT, four (50%) with the LBT and none with the methacholine challenge [provocative dose of methacholine causing a 20% fall in FEV1 (PD(20)) <or= 2 micromol]. There were no differences in the prevalence of AHR to either EVH or methacholine (PD(20) <or= 8 micromol) among the adolescent swimmers, the asthmatic adolescents and the unselected adolescents. When looking at airway responsiveness as a continuous variable, the swimmers were more responsive to EVH than were the unselected subjects, and less responsive to methacholine than were the asthmatic adolescents. There were no differences in FeNO, EBC pH or in the cellular composition of the sputum among the three groups. Lung function, FeNO, EBC pH, EBC lactate and differential cell counts in sputum were not acutely affected by the swimming session. We found that the EVH test is the most sensitive test for identifying AHR in elite athletes when using the diagnostic criteria set forward by the International Olympic Committe. Whereas a high prevalence of AHR in adult swimmers was found, the prevalence of AHR in the adolescent swimmers did not differ from that in unselected adolescents nor did the adolescent swimmers have signs of airway inflammation. There was no acute effect of a swimming training session in an indoor chlorinated pool on lung function or airway composition in adolescent swimmers. We believe that elite swimming results in airway changes with AHR and airway inflammation.

Airway Responses to Eucapnic Hyperpnea, Exercise, and Methacholine in Elite Swimmers

The International Olympic Committee Medical Commission (IOC-MC) requires athletes to provide the result of an objective test to support a diagnosis of asthma or exercise-induced bronchoconstriction (EIB) if they want to inhale a beta-2-agonist. The purpose of the study was to evaluate the airway response to a methacholine challenge and to hyperpnea induced by exercise in the field and in the laboratory or that induced voluntarily by eucapnic hyperpnea in a group of female elite swimmers. Sixteen female nonasthmatic elite swimmers performed a eucapnic voluntary hyperpnea (EVH) test, a field-based exercise test (FBT), a laboratory-based exercise test (LBT), and a methacholine challenge. The criteria suggested by the IOC-MC were used to define a positive response to the challenges (EVH, field test, and laboratory test: minimum 10% decrease in FEV1; methacholine: PD20 < or = 2 micromol). Eight swimmers (50%) had at least one positive test to hyperpnea. Five were identified with the EVH test, four with FBT, and four with LBT. None were identified using methacholine. Three swimmers with airway hyperresponsiveness to exercise would have been identified using a higher cutoff for methacholine (PD20 < or = 8 micromol). The EVH test is the test that diagnoses most swimmers with an abnormal response to hyperpnea, but not all cases of EIB are identified with the EVH test. Performing a methacholine test using IOC-MC's cutoff value does not improve the chances of diagnosing EIB. We recommend performing the EVH test when diagnosing and evaluating EIB in elite swimmers and if EVH test negative then proceeding to a strenuous LBT.

How Can We Assess Outcomes of Clinical Trials: The MCID Approach

Interpreting changes in outcomes of clinical trials in chronic obstructive pulmonary disease should be viewed from a broader perspective than only the statistical significance of the findings. The minimal clinical difference in outcome measures provides a conceptual framework to assist in clinical trial interpretation and a methodology to assess the clinical relevance of study results. Use of distribution-based techniques, comparison with other external measures, and opinions from experts, clinicians and patients can assist in minimal clinically important difference development. Although the minimal clinically important difference has been suggested for a wide range of outcomes of importance in chronic obstructive pulmonary disease, many have not been subjected to rigorous analysis. For newer tools such as activity monitors and questionnaires and measures not widely employed such as laboratory-based exercise tests, minimal clinically important differences remain to be determined.

Pilot study of fitness training and exercise testing in polyarticular childhood arthritis

To 1) assess the safety and feasibility of laboratory-based exercise testing in juvenile idiopathic arthritis (JIA), 2) test the safety and feasibility of a 3-month exercise program in JIA, 3) assess pain during exercise in JIA, 4) compare ratings of perceived effort (RPE) with heart rate (HR) achieved, and 5) estimate the training effect on metabolic efficiency of gait as measured by submaximal exercise testing. Nine children with JIA were enrolled in a 12-week circuit training program involving pool, stationary bicycle, treadmill, and Fitball. They underwent formal exercise testing before and after the program, underwent a full joint assessment, were administered the Childhood Health Assessment Questionnaire and Juvenile Arthritis Functional Status Index, and were assessed for overall quality of life and health-related quality of life. A visual analog scale was used to assess pain during testing and training, and the Borg scale was used to measure RPE. Children with JIA were able to participate in exercise testing without any significant problems. Children with severe hip disease dropped out of the exercise program due to pain during the exercise sessions and worsened arthritis symptoms. Target HR was achieved and correlated with RPE in the bicycle and treadmill sessions. Submaximal exercise testing showed an improvement with a small to moderate effect size. This study suggests that it is safe, feasible, and acceptable for children with arthritis, in the absence of severe hip involvement, to participate in formal exercise testing and structured fitness programs.

Assessing exercise capacity, quality of life and haemodynamics in heart failure: do the tests tell us the same thing?

The objective measurement of exercise tolerance is an important component of heart failure trials. The use of laboratory-based treadmill exercise testing has attracted criticism, however, as being unrepresentative of patients' true capabilities. To examine the relationships between tests of exercise capacity, quality of life and haemodynamics in patients with stable symptomatic heart failure. Thirty-six patients with mild-moderate chronic heart failure were studied. Exercise capacity was assessed in the laboratory by maximal treadmill tests and self-paced corridor walk tests, and in the patients' homes by hip-borne pedometers. Quality of life was assessed by a disease-specific questionnaire. Cardiac output and limb blood flow were measured by non-invasive techniques. Customary activity as assessed by pedometer scores correlated with quality of life questionnaire scores (r(S) = 0.47, P = 0.04), and both variables correlated with limb (calf) blood flow (pedometer scores: r(S) = 0.39, P = 0.03; quality of life scores: r(S)= 0.50, P = 0.04). The laboratory-based maximal treadmill test correlated with the self-paced corridor walk test, but neither of these tests correlated with pedometer scores, quality of life or haemodynamics. Different methods of assessing exercise capacity do not appear to give comparable results and bear different relationships to haemodynamic variables and quality of life. Pedometer scores of customary activity may better reflect patients' quality of life and appear to be more closely related to limb blood flow than the maximal treadmill exercise test or the corridor walk test. The sole use of laboratory-based exercise tests in therapeutic trials may give a misleading assessment of treatment efficacy in heart failure patients.

Relation of daily activity levels in patients with chronic heart failure to long-term prognosis

Symptom-limited, laboratory-based exercise tests are often used to define prognosis in patients with chronic heart failure, but they do not relate to measures of normal daily activity. Invasive measures of central hemodynamics similarly relate poorly to outcome. Pedometer scores of weekly walking are markedly reduced in patients with heart failure, but whether this less artificial measure of exercise capacity is important in predicting prognosis is not known. Eighty-four patients with chronic heart failure were followed for a mean of 710 days during which 44 died and 3 underwent cardiac transplantation. Symptom-limited treadmill exercise capacity using 2 different protocols did not predict survival, whereas reduced weekly pedometer scores were strong predictors of death (p < 0.001). Other variables that predicted death included resting cardiac output, arterial blood pressure, diuretic requirements, New York Heart Association class, increased bilirubin, and hyponatremia (all p < 0.01). Reduced levels of daily activity are strong predictors of death in chronic heart failure and appear more powerful than laboratory-based exercise tests. This type of assessment is valuable in identifying patients at high risk and provides an objective measure of incapacity during normal daily life. The exercise capacity of patients unable to exercise in the laboratory could also be assessed using this technique. This may prove invaluable in clinical and mortality trials.