Anaerobic Threshold Heart Rate Research Articles

Effect of the combined use of ivabradine and metoprolol in patients with acute myocardial infarction early after percutaneous coronary intervention: A randomized controlled study

ObjectiveTo investigate the effect and safety of the combined use of ivabradine and metoprolol in patients with acute myocardial infarction (AMI) after percutaneous coronary intervention (PCI). MethodsEighty patients with AMI were randomly divided into the ivabradine group and the control group. The ivabradine group was treated with ivabradine combined with metoprolol after PCI, while the control group was treated with metoprolol only. Both groups were treated continuously for 1 year. Echocardiography-derived parameters, heart rate, cardiopulmonary exercise testing (CPET) data, major adverse cardiac events (MACE) and myocardial markers were analyzed. The primary endpoint was the left ventricular ejection fraction (LVEF). The safety outcomes were blood pressure, liver and kidney function. ResultsThe LVEF was significantly higher in the ivabradine group than in the control group at 1 week, 3 months and 1 year after PCI. The heart rate of the ivabradine group was significantly lower than that of the control group at 1 week and 1month after PCI. The VO2max, metabolic equivalents, anaerobic threshold heart rate, peak heart rate, and heart rate recovery at 8 min of the ivabradine group were significantly higher than those of the control group at 1 year after PCI. Kaplan-Meier analysis demonstrated the one-year total incidence of MACE in the ivabradine group was significantly lower than that in the control group. The B-type natriuretic peptide of the ivabradine group was significantly lower than that of the control group on Day 2 and Day 3 after PCI. The high-sensitivity cardiac troponin I level of the ivabradine group was significantly lower than that of the control group on Day 5 after PCI. ConclusionEarly use of ivabradine in patients with AMI after PCI can achieve effective heart rate control, reduce myocardial injury, improve cardiac function and exercise tolerance, and may reduce the incidence of major adverse cardiac events. (Clinical research registration number: ChiCTR2000032731)

Effect of acute exercise on 12,13-dihydroxy-9Z-octadecenoic acid (12,13-diHOME) levels in obese male adolescents.

12,13-Dihydroxy-9Z-octadecenoic acid (12,13-diHOME) is a lipokine secreted from brown adipose tissue, and it has positive effects on dyslipidemia. Acute exercise has been shown to lead to an increase in its secretion. In this study, it was aimed to investigate the relationship of 12,13-diHOME with obesity, exercise and dyslipidaemia for the first time in the adolescent age group. Prospective study. Twenty-eight male adolescents with obesity and the same number of age-matched healthy normal-weight male controls. Fasting serum glucose, insulin, lipid and 12,13-diHOME levels were measured. Cardiopulmonary exercise testing was performed in all subjects using a stress test treadmill. Peak oxygen consumption (peak VO2) and anaerobic threshold heart rate (ATHR) were measured. Adolescents with obesity had lower 12,13-diHOME levels than normal-weight adolescents both before and after acute exercise (p = .025 and p = .019, respectively), and after acute exercise, 12,13-diHOME levels significantly increased in both groups (p = .001 for both). 12,13-diHOME levels negatively correlated with triglyceride, total cholesterol, LDL-C, and positively correlated with HDL-C. Also, peak VO2 and ATHR levels showed positive correlation with 12,13-diHOME levels. 12,13-diHOME levels were found to be lower in adolescents with obesity than normal-weight adolescents and increased with acute exercise. Also, the close relationship of this molecule with dyslipidaemia in addition to that with obesity suggests that it has an important role in the pathophysiology of these disorders. Further molecular studies will further elucidate the role of 12,13-diHOME in obesity and dyslipidaemia.

Effectiveness and Safety of Four Aerobic Exercise Intensity Prescription Techniques in Rehabilitation Training for Patients with Coronary Heart Disease

Methods A retrospective study was conducted on all patients with CHD who were admitted to CR and completed cardiopulmonary exercise tests (CPET) in Guangdong Hospital of traditional Chinese medicine. According to the risk stratification method of CHD, all participants were divided into three groups: low, moderate, and high risk. The training target heart rates (HRt) of each participant were calculated according to the formula of heart-rate-reserve (HRR), maximum-heart-rate (MHR), target-heart-rate (THR), and anaerobic threshold (AT) method provided in the guideline. Among them, the HRR method using the maximum-heart-rate obtained by the age formula was named “HRR method A,” and that using the actual measured peak heart rate was named “HRR method B.” For the three groups, the effectiveness and safety indexes at the target-heart-rate zone set by the different formulas above are counted and compared using CPET data. Results A total of 324 patients were included in the analysis. There was no significant difference between the target-heart-rate set by the HRR method A and AT method among the three groups (P > 0.05). The mean value of HRt set by other methods was lower than the AT heart rate (P < 0.05). The HRt set by the THR method was close to the AT, while that set by the MHR method was the lowest. The frequency of patients whose HRt was set by the MHR method was lower than the AT one, which was the highest. None of the participants had serious adverse events. There were no risks of ECG abnormalities in the low- and moderate-risk groups. The HRR method A had the highest incidence of various risks of ECG abnormalities, while the MHR method had the lowest one, and the safety of the THR method is close to that of the AT method (P < 0.05). Conclusion The heart rate calculated by HRR method A is more consistent with the actual AT. All four techniques are safe in low- and moderate-risk patients. In high-risk patients, using HRR method A has certain risks. It is recommended to use the MHR method for safety reasons, but its effectiveness is low. If considering both effectiveness and safety, the THR method can be conservatively selected at the beginning of the CR program.

Cardiorespiratory fitness in a population with different glucose metabolic statuses: low cardiorespiratory fitness increases the risk of early abnormal glucose metabolism.

Low cardiorespiratory fitness (CRF) is a risk factor for many chronic diseases. This study aimed to evaluate the CRF of a sample of adults with different glucose tolerance statuses to explore its relationship with early abnormal glucose metabolism according to sex. A total of 93 participants were assigned to three groups, i.e. the normal glucose tolerance (NGT) group, impaired glucose regulation (IGR) group and new-onset type 2 diabetes mellitus (T2DM) group, through an oral glucose tolerance test. Cardiopulmonary exercise testing was performed to evaluate the participants' CRF. The physical measurements (including height, weight, systolic blood pressure [SBP] and diastolic blood pressure) and laboratory test results (including fasting plasma glucose and two-hour plasma glucose [2h-PG]) of all participants were collected. Partial correlation, multiple linear regression (stepwise method) and logistic regression were used to analyse the data. Compared to the males with NGT, those with T2DM or IGR had a lower exercise time (P = 0.044), anaerobic threshold (AT) oxygen uptake (VO2) (P = 0.009), maximum VO2/kg (P = 0.041) and oxygen uptake efficiency slope (P = 0.002). The male participants with T2DM had lower AT power (P = 0.001) than those with IGR or NGT. Compared to the females with NGT, the AT heart rate (HR) (P = 0.003), AT SBP (P = 0.002) and maximum VO2/kg (P = 0.039) were lower in the female T2DM and IGR groups. The multiple linear regression (stepwise method) analyses showed that the maximum VO2/kg (β = -0.268, p = 0.026) and one-minute HR recovery (β = -0.239, p = 0.039) of the females improved the prediction of the 2h-PG when entered in the model. The logistic analysis results indicated that the VO2 max of the male participants was related to pre-diabetes (β = -0.003, p = 0.024) and that their AT power was associated with new-onset diabetes (β = -0.053, p = 0.010). Meanwhile, the AT SBP of the female participants was related to pre-diabetes (β = 0.120, p = 0.019), and their AT HR was related to new-onset diabetes (β = -0.102, p = 0.014). Low CRF is associated with abnormal glucose metabolism. The CRF is closely associated with the 2h-PG after glucose load and is an important risk factor for pre-diabetes and new-onset diabetes.

Consistency evaluation of target heart rate determined by anaerobic threshold and by resting heart rate in patients with coronary artery disease after percutaneous coronary intervention

Objective: To evaluate the consistency on the determination of target heart rate by simple calculation method based on resting heart rate and by anaerobic threshold method in cardiopulmonary exercise test (CPET) for patients with coronary artery disease after percutaneous coronary intervention (PCI). Methods: This study was a diagnostic test. Patients with coronary artery disease who underwent the first PCI in the Department of Cardiology of Peking University People's Hospital from October 2011 to April 2021 were enrolled. Patients were further divided into subgroups according to gender, age (<60 years group and ≥60 years group), with or without myocardial infarction history (myocardial infarction group and angina pectoris group) and whether β blockers were applied. The general clinical data of patients, resting heart rate (RHR) and anaerobic threshold heart rate in CPET were collected through the electronic medical record system. The simple target rate (RHR plus 20 or 30 bpm) and the target rate calculated by anaerobic threshold (anaerobic threshold heart rate minus 10 bpm) were both calculated in each patient. Consistency test of target heart rate derived by above the two methods was shown by intra-class correlation (ICC) and Bland-Altman plots. Results: A total of 439 patients were included, age was (56.2±8.8) years, body mass index was (25.77±2.34) kg/m2, there were 382 males (87.0%). The target heart rate determined by anaerobic threshold method was (90.0±11.8)bpm, and the simple target heart rate determined by RHR plus 20 bpm was (91.0±8.4)bpm. There was no significant difference on the target heart rate derived from the two calculation methods (P=0.091). The simple target heart rate determined by RHR plus 30 bpm was (101.0±8.4)bpm, which was significant higher than that determined by anaerobic threshold method (P<0.001). In the following analysis, RHR plus 20 bpm was defined as the simple target heart rate. The ICC value of target heart rate determined by anaerobic threshold and resting rate plus 20 bpm was 0.529(95%CI 0.458-0.593, P<0.001). Bland-Altman plots analysis showed that the ratio of the simple target heart rate and the target heart rate determined by anaerobic threshold method was 1.03±0.11 and the 95% limits of agreement (LOA) were 0.812-1.245. In the subgroup of patients aged<60 years (n=247), the ICC value was 0.492, the ratio by Bland-Altman plots analysis was 1.02±0.11 and LOA was 0.814-1.234; in the subgroup of patients aged ≥60 years (n=192), the ICC value was 0.566, the ratio by Bland-Altman plots analysis was 1.03±0.11 and LOA was 0.810-1.260. In male subgroup(n=382), the ICC value was 0.540, the ratio by Bland-Altman plots analysis was 1.03±0.11 and LOA was 0.813-1.246; in female subgroup(n=57), the ICC value was 0.445, the ratio by Bland-Altman plots analysis was 1.03±0.11 and LOA was 0.810-1.240.In myocardial infarction subgroup (n=186), the ICC value was 0.568, the ratio by Bland-Altman plots analysis was 1.02±0.11 and LOA was 0.810-1.227; in angina pectoris subgroup (n=253), the ICC value was 0.495, the ratio by Bland-Altman plots analysis was 1.04±0.11 and LOA was 0.813-1.260. In the subgroup of patients with β blockers (n=353), the ICC value was 0.520, the ratio by Bland-Altman plots analysis was 1.03±0.11 and LOA was 0.810-1.252; in the subgroup of patients without β blockers (n=86), the ICC value was 0.570, the ratio by Bland-Altman plots analysis was 1.02±0.10 and LOA was 0.821-1.219. Conclusions: The simple target heart rate determined by RHR plus 20 bpm is consistent with the target heart rate determined by anaerobic threshold in patients with coronary artery disease after PCI. But the simple target heart rate determined by RHR plus 20 bpm can't replace the target heart rate determined by anaerobic threshold in this patient cohort.

A Correlational Study on Cardiopulmonary Endurance in Male Patients with New-Onset Type 2 Diabetes.

BackgroundCardiopulmonary exercise tests (CPETs) are widely used non-invasive and reliable functional evaluation methods. This study investigated the correlation between cardiopulmonary endurance indices and plasma glucose levels and abdominal visceral fat in males with new-onset type 2 diabetes.MethodsA total of 136 male individuals, who had been treated in the First Hospital of Qinhuangdao City, were selected to form a new-onset type 2 diabetes group (66 cases) and a control group (70 cases); individuals were divided into three groups (Q1, Q2, and Q3) from low to high according to their anaerobic threshold (AT) oxygen uptake (VO2), AT VO2/kg (VO2 per kg of body weight), peak VO2, peak VO2/kg, AT heart rate (HR), peak HR, and HR recovery after 1 minute. A cardiopulmonary exercise test was used to determine the VO2 of each group of subjects for VO2 max and AT VO2/kg, HR, and HR recovery after 1 minute. The differences in fat areas and plasma glucose levels were compared under different cardiorespiratory endurance indicators.ResultsCompared with the control group, the abdominal visceral fat (AVF) area, fasting plasma glucose (FPG), and postprandial plasma glucose (PPG) levels increased in the new-onset type 2 diabetes group. Concurrently, AT VO2, AT VO2/kg, peak VO2, peak VO2/kg, AT HR, peak HR, and 1-minute HR recovery all decreased, and the difference between the groups was statistically significant (P<0.05). The higher the AT VO2 and peak VO2 values, the lower the PPG level (P<0.05) and the smaller the area of abdominal visceral fat (P<0.05). The AT VO2/kg and peak VO2/kg values were negatively correlated with the abdominal visceral fat area, while other indicators had no obvious relationship with either plasma glucose levels or the area of fat.ConclusionThe levels of blood glucose and visceral fat are correlated with cardiopulmonary function. With the increase in blood glucose levels and visceral fat, the indices of cardiopulmonary function gradually decrease. The correlation between different cardiopulmonary function indices and blood glucose levels and visceral fat was different.

Effects of 2 Models of Aquatic Exercise Training on Cardiorespiratory Responses of Patients With Type 2 Diabetes: The Diabetes and Aquatic Training Study—A Randomized Controlled Trial

There are a lack of clinical trials with suitable methodological quality that compare aquatic exercise training types in type 2 diabetes (T2D) treatment. This study aimed to compare the effects of aerobic and combined aquatic training on cardiorespiratory outcomes in patients with T2D. Untrained patients with T2D were randomized to receive an aerobic aquatic training, a combined aquatic training, or a procedure control in 3 weekly sessions for 15 weeks. The sessions were 50 minutes long. The intensities were from 85% to 100% of heart rate of anaerobic threshold and at maximal velocity for aerobic and resistance parts, respectively. Resting heart rate, peak oxygen uptake (VO2peak), and oxygen uptake corresponding to second ventilatory threshold and its relation with VO2peak were evaluated. Participants were 59.0 (8.2) years old and 51% women. Intervention groups increased in VO2peak (aerobic aquatic training group: 4.48mL·kg-1·min-1, P = .004; combined aquatic training group: 5.27mL·kg-1·min-1; P = .006) and oxygen uptake corresponding to second ventilatory threshold, whereas the control group presented an increase in oxygen uptake corresponding to second ventilatory threshold and minimal change in VO2peak. Aerobic and combined aquatic exercise interventions improve the cardiorespiratory fitness of patients with T2D.

Acute and chronic glycemic effects of aerobic training in patients with type 2 diabetes

The aim of the present study was to analyze acute glycemic effects in different moments of an aerobic training, as well as to analyze the chronic effect of training, in patients with type 2 diabetes mellitus (T2D). The participants performed 16 weeks of interval aerobic training with three weekly sessions. The main part of each session consisted of nine blocks of five minutes, in which four minutes consisted of stimulus between 85% and 95% of the anaerobic threshold heart rate (ATHR) and one minute consisted of recovery below 85% of the ATHR, totalizing 45 minutes. Capillary glucose was assessed before, immediately after and 30 minutes after the first and the last training sessions. Glycated hemoglobin (HbA1c) was assessed before and after the intervention. Paired t-test and Generalized Estimating Equations were performed for the analyses; α = 5%. The participants were seven individuals (four women) aged 59.60±6.69 years. In the first session, glucose values immediately after and 30 minutes after exercise were lower than pre-exercise values. On the other hand, in the last training session, only the glucose values immediately after exercise were lower than pre-exercise values. Analyzing the glycemic reductions, the first session presented a greater reduction immediately after (p = 0.042) and 30 minutes after exercise (p = 0.010). Regarding chronic glycemic effects, an increase (p = 0.010) in HbA1c levels was observed after training. It is concluded that, after 16 weeks of training without progression of duration and intensity, the exercise loses its acute glycemic effect, and may be even insufficient to reduce HbA1c levels.

Cardiopulmonary exercise test and bioimpedance as prediction tools to predict the outcomes of obesity treatment.

INTRODUCTION Obesity impacts the global population. Bioelectrical impedance analysis (BIA) and cardiopulmonary exercise test [CPET]) may help modify the treatment. OBJECTIVES We aimed to compare BIA and CPET results in obese and lean indivisuals, assess changes in BIA and CPET during obesity treatment, and indentify parameters predicting treatment outcome. PATIENTS AND METHODS We enrolled 200 obese patients, of whom 45 underwent a lifestyle modification treatment, and 32 lean individuals (controls). Lifestyle modifications included diet, rehabilitation, education, and behavioral therapy. The diet was based on body composition assessed by BIA and fat metabolism assessed by CPET. The intensity of exercise in the rehabilitation program was based on CPET, mainly peak oxygen uptake (VO2peak), fat metabolism (FAT), and fat heart rate (FAT HR). The protocol duration was 12 weeks. RESULTS Obese patients differed from lean controls with regard to VO2peak (P <0.0001), oxygen uptake at anaerobic threshold (P <0.0002), respiratory exchange ratio (P <0.014), oxygen uptake to work rate slope (P <0.0004), FAT (P <0.001), FAT HR (P <0.0008), anaerobic threshold heart rate (P <0.0003), as well as fat mass (P = 0.01), fat‑free mass (P = 0.007), resting metabolic rate (RMR) (P = 0.007), total body water (P = 0.01), and extracellular water (P = 0.004). The treatment resulted in increased RMR (P <0.02) and VO2peak (P <0.002), as well as reduced fat tissue (P <0.006) and resting heart rate (P <0.017). The prediction model based on FAT HR, resting heart rate, and FAT enabled the prediction of treatment outcomes in 92% of patients. CONCLUSIONS Obese patients had pathological FAT and impaired exercise tolerance. Changes in BIA and CPET prove the metabolic impact of lifestyle modification treatment.

OR-030 Influences of Four Weeks Intermittent Hypoxic Training on Aerobic Ability of High-Level Race Walking Athletes

OR-030 Influences of Four Weeks Intermittent Hypoxic Training on Aerobic Ability of High-Level Race Walking Athletes

The Yo-Yo IR2 test in professional basketball players

The aim of this study was to investigate the relationship between direct method and indirect method (Yo-Yo Intermittent Recovery Test Level II) that are used to determine aerobic capacity and endurance. Fourteen basketball players (22.49 ±04.82 year-old with the height 192.36±5.90 cm, weight 89.21±7.6 kg, Body fat percentage 11.07 ± 1.82 %) voluntarily participated in this study. Yo-Yo Intermittent Recovery Test Level II protocol (YIRT 2) was implemented to participants. Distance covered by the athletes, estimated VO2max, direct VO2max, Anaerobic threshold VO2 and Anaerobic threshold heart rate (HRAT) values were recorded. Direct VO2max and other respiratory parameters were measured with telemetric gas analyzer. After 5 minute rest in supine position heart rates (HRrest), rest lactate levels (LArest) and maximal heart rate (HRmax) during the test and post test lactate levels (LApost) were measured. Pearson Correlation Test was used to determine the relationship between the variables. P value was set at 0,05. According to the findings, positively significant large correlation was found between estimated VO2max and direct VO2max(r = 0.504, p &lt; 0.05), HRmax (r = 0.501, p &lt; 0.05), positively significant large correlation was found between distance and Direct VO2max(r = 0.521, p &lt; 0.05), HRmax (r = 0.516, p &lt; 0.05). There is no significant relationship except above-mentioned variables (p&lt;0.05). YIRT2 can guess VO2max of professional male basketball players and can be used to evaluate endurance.

Quality of life and sleep quality are similarly improved after aquatic or dry-land aerobic training in patients with type 2 diabetes: A randomized clinical trial

ObjectivesTo compare the effects of two aerobic training models in water and on dry-land on quality of life, depressive symptoms and sleep quality in patients with type 2 diabetes. DesignRandomized clinical trial. MethodsThirty-five patients with type 2 diabetes were randomly assigned to aquatic aerobic training group (n=17) or dry-land aerobic training group (n=18). Exercise training length was of 12 weeks, performed in three weekly sessions (45min/session), with intensity progressing from 85% to 100% of heart rate of anaerobic threshold during interventions. All outcomes were evaluated at baseline and 12 weeks later. ResultsIn per protocol analysis, physical and psychological domains of quality of life improved in both groups (p<0.05) without between-group differences. Overall quality of life and sleep quality improved in both groups (p<0.05), without between-group differences in per protocol and intention to treat analysis. No changes on depressive symptoms were observed in both groups at follow-up. ConclusionsAerobic training in an aquatic environment provides similar effects to aerobic training in a dry-land environment on quality of life, depressive symptoms and sleep quality in patients with type 2 diabetes.Clinical trial reg. no. NCT01956357, clinicaltrials.gov.

Glycemic reductions following water- and land-based exercise in patients with type 2 diabetes mellitus

PurposeTo assess the acute glucose responses to the first sessions of three mesocycles of water- and land-based aerobic exercise. MethodsThe water-based exercise group (WBE, n = 14; 54.1 ± 9.1 years) performed deep water walking and/or running, while the land-based exercise group (LBE, n = 11; 60.1 ± 7.3 years) performed walking and/or running on athletic track. In the first mesocycle, patients trained at 85–90% of their anaerobic threshold (AT) for 35 min, progressing to 90–95% of the AT in the second mesocycle, and 95–100% of the AT in the last mesocycle. Capillary glucose was assessed before and immediately after the first session of each mesocycle. ResultsThere was glycemic reduction (p < 0.001) in all sessions, with relative reductions of 19%, 29% and 24% for the WBE and 24%, 29% and 27% for the LBE in the mesocycles 1, 2 and 3, respectively. There were no found differences between groups and between mesocycles. ConclusionsThe acute response of blood glucose to aerobic training between 85 and 100% of the heart rate of AT is effective and independent of the environment in which it is performed. Clinical trial reg. no. NCT01956357, clinicaltrials.gov.

Glucose control can be similarly improved after aquatic or dry-land aerobic training in patients with type 2 diabetes: A randomized clinical trial.

To compare the effects of two aerobic training methods in water and on dry-land on glycemic, lipid, inflammatory, hormonal, cardiorespiratory, and functional outcomes in patients with type 2 diabetes. Randomized clinical trial. Thirty-five patients with type 2 diabetes were randomly assigned to aquatic aerobic training group (n=17) or dry-land aerobic training group (n=18). Exercise training interventions had duration of 12 weeks, performed in three weekly sessions (45min/session), with intensity progressing from 85% to 100% of heart rate of anaerobic threshold during interventions. All outcomes were evaluated at baseline and 12 weeks later. Patients were 56.7±7.9 years old. Decreases in glycated hemoglobin were observed in both groups (AT: -0.42±0.28%, DLT: -0.35±1.8%). Total cholesterol, high density lipoprotein, low density lipoprotein levels, plasma renin activity, angiotensin II concentrations, C-reactive protein, systolic blood pressure, resting heart rate, and timed up and go test performed at the usual speed also decreased in both groups in response to both interventions (p<0.05), without between-group differences. Both groups increased the ratio between oxygen uptake at the anaerobic threshold and oxygen uptake of peak (p=0.01). Aerobic training in an aquatic environment provides effects similar to aerobic training in a dry-land environment in patients with type 2 diabetes.

Assessment of professional baseball players aerobic exercise performance depending on their positions.

This study reports the average and SD of professional baseball players' cardiorespiratory endurance, maximum oxygen consumption, oxygen consumption during anaerobic threshold, maximum oxygen consumption of anaerobic threshold %, maximum heart rate, and heart rate of anaerobic threshold. We also report the comparison between pitchers and fielders. Considering the total number of results, percentile was used and results were classified into 5 grades. One professional baseball players' organization with more than 14 years of experience participated in this study. First, we observed that the average pitchers' V[Combining Dot Above]O2max was 53.64 ml·kg·min, whereas the average fielders' was 52.30 ml·kg·min. These values were lower than other sports players. Second, in case of the V[Combining Dot Above]O2AT, pitchers showed 39.35 ml·kg·min and fielders showed 39.96 ml·kg·min. %V[Combining Dot Above]O2AT showed a significant difference of 71.13% between pitchers and fielders-pitchers, whereas fielders showed 73.89% (p < 0.01). Third, maximal heart rates were measured at 188.69 b·min (pitchers) and 187.79 b·min (fielders). These were lower than college baseball players and higher than other sports players. In conclusion, both professional baseball pitchers and fielders should be aware of the necessity of systematic cardiorespiratory endurance data analysis. Moreover, baseball teams, athletic trainers, and coaches should also be aware of the importance of cardiorespiratory endurance.

SAT0588-HPR Swimming is as Effective as Walking for Treating Fibromyalgia: a Randomized Controlled Trial.

BackgroundBackground: Fibromyalgia (FM) is a chronic widespread pain syndrome that causes deterioration of physical capacity. Exercises are fundamental in the treatment of FM, however, it is not known the effects...

Estimation of the Anaerobic Threshold from Heart Rate Variability in an Incremental Swimming Test

This study aimed to evaluate, in swimming, the agreement between the anaerobic threshold (AT) as determined from the analysis of blood lactate concentration ([La]) and from a new method based on the heart rate (HR) variability (HRV). Fourteen high-level swimmers completed an incremental 7 × 200-m front crawl test, during which the HRV was measured continuously and [La] was collected after each step. To individuate the AT, the trends of the high-frequency HRV spectral power (HFPOW) and of the fraction of HFPOW relative to the respiratory sinus arrhythmia (HFPOW-RSA) were analyzed. In all the subjects, an abrupt increase of both HFPOW and HFPOW-RSA was observed and associated with the AT. The AT parameters determined, respectively, from [La] and HFPOW-RSA were similar (p > 0.05) and highly correlated (HR: 182.0 ± 8.1 vs. 181.1 ± 8.2 b·min, r = 0.93, 95% limits of agreement [LoA]: -6.7 to 4.9 b·min; velocity: 1.47 ± 0.11 vs. 1.47 ± 0.11 m·s, r = 0.98, 95% LoA: -0.05 to 0.05 m·s). Instead, the AT HR and velocity obtained from HFPOW (179.2 ± 8.4 b·min; 1.45 ± 0.11 m·s) were correlated to the corresponding parameters determined from [La] (HR: r = 0.84; velocity: r = 0.94) but underestimated them slightly (95% LoA: -11.9 to 6.3 b·min and -0.11 to 0.05 m·s). These results demonstrate that the AT can be assessed from the HRV in swimming, providing an important testing tool for coaches. Furthermore, using the actual respiratory spectral component, rather than the total HF spectral power, allows us to obtain a more accurate estimate of AT parameters.

The Fractional Utilisation of Maximal Oxygen Consumption during Execution of Ground Strokes and Simulated Match in 14 to 18 years Malaysian Singles Tennis Players

The purpose of the present study was to determine the fractional utilisation of maximum oxygen uptake capacity (% VO2max) during execution of ground strokes and tennis match play. Ten male Malaysian state-level tennis players participated in this study. Age, height, weight and VO2max of the players were 15.3 + 1.2 years, 164.0 + 7.4 cm, 52.3 + 11.5 kg and 51.7 + 7.3 ml·kg - ¹·min - ¹ respectively. This study was conducted in 3 phases: laboratory test (Phase I), on-court test (Phase II) and simulated match (Phase III). Fraction of VO2max during execution of forehand and backhand strokes were 71.6 + 10.9% and 72.3 + 8.8% respectively, whereas tennis match play demanded 69.3 + 9.8% of VO2max. Execution of forehand and backhand strokes led to a blood lactate concentration of approximately 6 mmol·L??1, indicating the involvement of anaerobic glycolysis. On the other hand, due to the intermittent nature of the game and the work-rest ratio of 1 : 2.2, the post-match blood lactate was found to be 3.21 + 0.2 mmol·L??1, reflecting an aerobic dominance in the game. The mean match heart rate (154.3 + 15.4 beats·min - ¹) was lower than mean anaerobic threshold heart rate (164.7 + 5.7 beats·min - ¹), signifying a lower blood lactate level less than 4.0 mmol·L??1 in a tennis match. It This might be due to the fact that long rest pauses caused removal of blood lactate as well as recovery of heart rate. Video analysis of the matches revealed that the players executed more forehand strokes (P<0.001) than the backhand strokes. Since similar heart rate and VO2 responses were observed for forehand and backhand strokes, it is suggested that the players should train themselves equally on both ground strokes. During the longest rally, mean heart rate of the players was 174.9 + 3.1 beats·min - ¹, which corresponded to 84.5 + 2.2% of VO2max. In addition, rallies per game, mean rally duration and strokes per rally were found to be 5.7 + 2.4, 4.5 + 1.5 seconds and 2.8 + 0.8 shots, respectively. Hence, it is concluded that the Malaysian state-level tennis players possessed a moderately good aerobic capacity. This can be improved to the international standard through endurance and intermittent type of training. Improvement in VO2max may enhance the playing intensity of the match as well a better recovery in the rest pauses and also delay the onset of fatigue during a match. From video match analysis and heart rate VO2 relationship, it is suggested that the players should also improve the alactic anaerobic component through short bursts of repeated movements of 5-8 seconds durations.

Transferability of Running and Cycling Training Zones in Triathletes: Implications for Steady-State Exercise

The primary objective of this study was to determine whether physiological measurements obtained from one mode of testing and training could be applied to another mode, as in prescribing heart rate (HR) zone training from cyling to running. Secondary objectives were 1) to assess the validity of applying data from incremental testing to steady-state exercise, and 2) to compare breakpoint in respiratory rate (RR) with the conventional method of anaerobic threshold (AT) breakpoint, the ventilatory equivalent for oxygen VE/VO2). Sixteen experienced triathletes performed VO2max testing on a cycle ergometer (CE) and treadmill (TM). In addition, a 30-minute time trial (TT) was performed on a CE. No significant differences were observed between modes of testing for VO2max (CE = 68.4 +/- 11.1 mlxkgxmin, TM = 69.0 +/- 13.2 mlxkgxmin), maximum HR (CE = 177.1 +/- 6.1 bpm, TM = 178.1 +/- 7.4 bpm), or AT (CE AT HR = 153.9 +/- 10.5 bpm, TM AT HR = 157.0 +/- 9.5 bpm). Although the mean difference in AT HR was small (3.1 bpm), a small correlation coefficient (0.321) between the AT for the 2 testing modes resulted in a large total error (TE = 12.1 bpm), indicating limited practical application of training zones between modes of testing. Mean TT HR and mean TT RR were significantly greater than mean AT HR (159.4 +/- 8.9 vs. 153.9 +/- 10.5 bpm) and mean AT RR (37.8 +/- 6.0 vs. 32.4 +/- 3.2 breaths per minute) because of significant "drift" in these 2 variables over time, whereas TT watts and AT watts were not significantly different (249.1 +/- 47.8 vs. 240.6 +/- 71.1 W). Finally, a significant difference and large TE (9.0 bpm) betweenVE/VO2 AT HR and the RR AT HR (153.9 +/- 10.5 and 158.4 +/- 10.0 bpm) may preclude the practical use of the RR breakpoint. From the results of this study, it is recommended that the triathlete perform sport-specific testing to assess training zones for cycling and running. In addition, because both HR and RR "drift" upward with steady-state exercise, AT RR and AT HR determined by incremental testing underestimate steady-state HR and RR. For this reason, monitoring wattage during steady-state exercise may be more appropriate than monitoring HR and RR.

Resposta cronotrópica ao teste cardiopulmonar após o uso de cimetidina

To test the hypothesis that the administration of cimetidine will modify the chronotropic response to exercise testing through a random clinical trial. The study selected 24 eligible healthy subjects, ages between 20 and 68 years, not athletes, who agreed to undergo cardiopulmonary exercise testing after the administration of placebo and 400 mg of cimetidine twice a day for one week. The tests were performed on a treadmill using a ramp protocol and direct analysis of the expired gases. Peak, resting and anaerobic threshold heart rate were recorded. The twenty subjects studied were equally distributed across sex with mean (+/- SD) age 43 +/- 11 years. Tests on placebo and on cimetidine presented similar duration (578 +/- 90 sec vs 603 +/- 131 sec) and similar peak oxygen uptake (35 +/- 8 ml/kg.min vs 35 +/- 8 ml/kg.min). Cimetidine administration had no significant effect on resting heart rate (75 +/- 10 bpm vs 74 +/- 8 bpm), heart rate at peak exercise (176 +/- 12 bpm vs 176 +/- 11 bpm), and on the difference between the peak and the resting heart rates--delta HR (101 +/- 14 bpm vs 101 +/- 13 bpm). The administration of cimetidine for 7 days has no significant effect on the chronotropic response to exercise testing.