Aerobic exercise intensity assessment and prescription in cardiac rehabilitation: a joint position statement of the European Association for Cardiovascular Prevention and Rehabilitation, the American Association of Cardiovascular and Pulmonary Rehabilitation, and the Canadian Association of Cardiac Rehabilitation

Estimation of ventilatory thresholds during exercise using respiratory wearable sensors

Ventilatory thresholds (VTs) are key physiological parameters used to evaluate physical performance and determine aerobic and anaerobic transitions during exercise. Current assessment of these parameters requires ergospirometry, limiting evaluation to laboratory or clinical settings. In this work, we introduce a wearable respiratory system that continuously tracks breathing during exercise and estimates VTs during ramp tests. We validate the respiratory rate and VTs predictions in 17 healthy adults using ergospirometry analysis. In addition, we use the wearable system to evaluate VTs in 107 recreational athletes during ramp tests outside the laboratory and show that the mean population values agree with physiological variables traditionally used to exercise prescription. We envision that respiratory wearables can be useful in determining aerobic and anaerobic parameters with promising applications in health telemonitoring and human performance.

Association among cardiopulmonary and metabolic rehabilitation, arrhythmias, and myocardial ischemia responses of patients with HFpEF or HFmrEF

There's limited evidence of the potential benefits of cardiopulmonary and metabolic rehabilitation (CPMR) in patients with heart failure with preserved ejection fraction (HFpEF) or mildly reduced ejection fraction (HFmrEF) and coronary artery disease (CAD). The aim of this study was to investigate the impact of CPMR on the myocardial ischemia response (MIR), exercise-induced arrhythmias (EIA), New York Heart Association (NYHA) functional class, heart rate recovery (HRR), Borg CR10 perceived symptoms, and the SF-36 physical and mental health summary scores. A prospective cohort study was conducted with 106 patients undergoing 12 weeks of CPMR who completed two exercise tests pre- and post-CPMR: 1) maximum incremental test (CPX) and 2) submaximal constant load test (SUB). After CPMR, the effects on MIR, EIA, NYHA functional class, and HRR during both tests were analyzed. There was a significant change in NYHA functional classes after CPMR, with 96% of the patients in class I (vs 62% pre-CPMR, P<0.0001), 4% in class II (vs 32%), and none in class III (vs 6%). There was a significant reduction in the frequency of EIA (P<0.05) and MIR (P<0.001) and a significantly improved performance on both CPX and SUB tests (P<0.0001). Lastly, there was significant progress in the recovery metrics like HRR (P<0.0001), the Borg CR10 (P<0.0001), and the SF-36 summary scores (P<0.0001). The CPMR resulted in a significant decrease in EIA, delayed ischemia threshold in CPX and SUB tests, increased functional capacity, and improved quality of life.

Moderate to Vigorous Intensity Locomotor Training After Stroke: A Systematic Review and Meta-analysis of Mean Effects and Response Variability

BACKGROUND AND PURPOSE

This meta-analysis quantified mean effects of moderate to vigorous intensity locomotor training (LT mv ) on walking outcomes in subacute and chronic stroke, and the magnitude of variability in LT mv response.

METHODS

Databases were searched for randomized trials comparing LT mv with no intervention, nongait intervention, or low-intensity gait training. Comfortable gait speed (CGS), fastest gait speed (FGS), 6-minute walk test (6MWT), walking activity (steps per day), and adverse effect/event (AE) data were extracted. Pooled estimates were calculated for mean changes, AE relative risks, and the standard deviation of response (SD response ) to LT mv versus control groups, stratified by study chronicity where possible.

RESULTS

There were 19 eligible studies (total N = 1096): 14 in chronic stroke (N = 839) and 5 in subacute stroke (N = 257). Compared with control interventions, LT mv yielded significantly greater increases in CGS (chronic, +0.06 m/s [95% confidence interval (CI), 0.01-0.10]; subacute, +0.16 [0.12-0.19]; subacute vs chronic, P = 0.03), FGS (chronic, +0.07 m/s [0.02-0.13]; subacute, +0.21 [0.01, 0.41]; P = 0.04), and 6MWT (chronic, +33 m [24-42]; subacute, +51 [26-77]; P = 0.054) but not steps/day (+260 [-1159 to 1679]). There were no treatment-related serious AEs among 398 LT mv participants in 14 AE-reporting studies. SD response estimates indicated substantial response variability: CGS, 0.11 m/s [0.00-0.15]; FGS, 0.14 m/s [-0.00 to 0.20]; and 6MWT, 41 m [27-51].

DISCUSSION AND CONCLUSIONS

LT mv improves mean walking capacity outcomes in subacute and chronic stroke and does not appear to have high risk of serious harm. Response magnitude varies within and between chronicity subgroups, and few studies have tested effects on daily walking activity or non-serious AEs.Video Abstract available for more insights from the authors (see the Video, Supplemental Digital Content 1 available at: http://links.lww.com/JNPT/A452 ).

Do Clinical Exercise Tests Permit Exercise Threshold Identification in Patients Referred to Cardiac Rehabilitation?

BACKGROUND

To evaluate the feasibility of "threshold-based" aerobic exercise prescription in cardiovascular disease, we aimed to quantify the proportion of patients whose clinical cardiopulmonary exercise test (CPET) permit identification of estimated lactate threshold (θLT) and respiratory compensation point (RCP) and to characterize the variability at which these thresholds occur.

METHODS

Breath-by-breath CPET data of 1102 patients (65 ± 12 years) referred to cardiac rehabilitation were analyzed to identify peak O2 uptake (V˙O2peak; mL·min-1 and mL·kg-1·min-1) and θLT and RCP (reported as V˙O2, %V˙O2peak, and %peak heart rate [%HRpeak]). Patients were grouped by the presence or absence of thresholds: group 0: neither θLT nor RCP; group 1: θLT only; and group 2: both θLT and RCP.

RESULTS

Mean V˙O2peak was 1523 ± 627 mL·min-1 (range: 315-3789 mL·min-1) or 18.0 ± 6.5 mL·kg-1·min-1 (5.2-46.5 mL·kg-1·min-1) and HRpeak was 123 ± 24 beats per minute (bpm) (52 bpm-207 bpm). There were 556 patients (50%) in group 0, 196 (18%) in group 1, and 350 (32%) in group 2. In group 1, mean θLT was 1240 ± 410 mL·min-1 (580-2560 mL·min-1), 75% ± 8%V˙O2peak (52%-92%V˙O2peak), or 84% ± 6%HRpeak (64%-96%HRpeak). In group 2, θLT was 1390 ± 360 mL·min-1 (640-2430 mL·min-1), 70% ± 8%V˙O2peak (41%-88%V˙O2peak), or 78% ± 7%HRpeak (52%-96%HRpeak), and RCP was 1680 ± 440 mL·min-1 (730-3090 mL·min-1), 84% ± 7%V˙O2peak (54%-99%V˙O2peak), or 87% ± 6%HRpeak (59%-99%HRpeak). Compared with group 1, θLT in group 2 occurred at a higher V˙O2 but lower %V˙O2peak and %HRpeak (P < 0.05).

CONCLUSIONS

Only 32% of CPETs exhibited both θLT and RCP despite flexibility in protocol options. Commonly used step-based protocols are suboptimal for "threshold-based" exercise prescription.

Effects of cardiac rehabilitation on obese hypertensive patients: A controlled trial

INTRODUCTION

The relationship between obesity and hypertension is clearly known and cardiac rehabilitation (CR) is shown as an effective treatment method in both obese and hypertensive patients. The aim of this study is to reveal the effect of CR on obese hypertensive patients by comparing them with non-obese hypertensive patients.

METHODS

Eighty eligible, volunteer participants with hypertension (SBP ≥140mmHg and/or DBP ≥90mmHg) were enrolled in this study. The patients were divided into 2 groups according to their BMI values: obese (BMI ≥30kg/m2) hypertensive patients and non-obese (BMI <30kg/m2) hypertensive patients. The CR program, in which aerobic exercise training was the main part, was performed on the patients. At the end of the 10-week CR program, the resting SBP and DBP values were measured.

RESULTS

A total of 74 patients (37 obese and 37 non-obese) completed the study. After CR significant improvements were achieved in all evaluated parameters compared to pre-CR values. When the amounts of changes before and after CR were compared, the decrease in SBP was found to be significantly higher in obese patients compared to non-obese patients (p=.003). Higher BMI was associated with more reduction in SBP (r=0.287, p=0.013).

CONCLUSIONS

Exercise-based CR effectively reduced SBP in obese and non-obese hypertensive patients. However, it was more effective in obese patients compared to non-obese patients.

A Clinical Guide for Assessment and Prescription of Exercise and Physical Activity in Cardiac Rehabilitation. A CSANZ Position Statement

Patients with cardiovascular disease benefit from cardiac rehabilitation, which includes structured exercise and physical activity as core components. This position statement provides pragmatic, evidence-based guidance for the assessment and prescription of exercise and physical activity for cardiac rehabilitation clinicians, recognising the latest international guidelines, scientific evidence and the increasing use of technology and virtual delivery methods. The patient-centred assessment and prescription of aerobic exercise, resistance exercise and physical activity have been addressed, including progression and safety considerations.

Exercise intensity domains determined by heart rate at the ventilatory thresholds in patients with cardiovascular disease: new insights and comparisons to cardiovascular rehabilitation prescription recommendations

Objectives

To compare the elicited exercise responses at ventilatory thresholds (VTs: VT1 and VT2) identified by cardiopulmonary exercise testing (CPET) in patients with cardiovascular disease (CVD) with the guideline-directed exercise intensity domains; to propose equations to predict heart rate (HR) at VTs; and to compare the accuracy of prescription methods.

Methods

A cross-sectional study was performed with 972 maximal treadmill CPET on patients with CVD. First, VTs were identified and compared with guideline-directed exercise intensity domains. Second, multivariate linear regression analyses were performed to generate prediction equations for HR at VTs. Finally, the accuracy of prescription methods was assessed by the mean absolute percentage error (MAPE).

Results

Significant dispersions of individual responses were found for VTs, with the same relative intensity of exercise corresponding to different guideline-directed exercise intensity domains. A mathematical error inherent to methods based on percentages of peak effort was identified, which may help to explain the dispersions. Tailored multivariable equations yielded r2 of 0.726 for VT1 and 0.901 for VT2. MAPE for the novel VT1 equation was 6.0%, lower than that for guideline-based prescription methods (9.5 to 23.8%). MAPE for the novel VT2 equation was 4.3%, lower than guideline-based methods (5.8%-19.3%).

Conclusion

The guideline-based exercise intensity domains for cardiovascular rehabilitation revealed inconsistencies and heterogeneity, which limits the currently used methods. New multivariable equations for patients with CVD were developed and demonstrated better accuracy, indicating that this methodology may be a valid alternative when CPET is unavailable.

Training parameters and longitudinal adaptations that most strongly mediate walking capacity gains from high-intensity interval training post-stroke

Background

Locomotor high-intensity interval training (HIIT) has been shown to improve walking capacity more than moderate-intensity aerobic training (MAT) after stroke, but it is unclear which training parameter(s) should be prioritized (e.g. speed, heart rate, blood lactate, step count) and to what extent walking capacity gains are the result of neuromotor versus cardiorespiratory adaptations.

Objective

Assess which training parameters and longitudinal adaptations most strongly mediate 6-minute walk distance (6MWD) gains from post-stroke HIIT.

Methods

The HIT-Stroke Trial randomized 55 persons with chronic stroke and persistent walking limitations to HIIT or MAT and collected detailed training data. Blinded outcomes included 6MWD, plus measures of neuromotor gait function (e.g. fastest 10-meter gait speed) and aerobic capacity (e.g. ventilatory threshold). This ancillary analysis used structural equation models to compare mediating effects of different training parameters and longitudinal adaptations on 6MWD.

Results

Net gains in 6MWD from HIIT versus MAT were primarily mediated by faster training speeds and longitudinal adaptations in neuromotor gait function. Training step count was also positively associated with 6MWD gains, but was lower with HIIT versus MAT, which decreased the net 6MWD gain. HIIT generated higher training heart rate and lactate than MAT, but aerobic capacity gains were similar between groups, and 6MWD changes were not associated with training heart rate, training lactate, or aerobic adaptations.

Conclusions

To increase walking capacity with post-stroke HIIT, training speed and step count appear to be the most important parameters to prioritize.

Effectiveness of Unsupervised Exercise Therapy After Endovascular Treatment for an Iliac Occlusive Lesion

Objective

Exercise therapy has acceptable outcomes for patients with intermittent claudication (IC), but there are few reports on the results of continuous unsupervised exercise therapy after endovascular treatment (EVT) for an iliac lesion. The aim of this study is to analyze the long-term outcomes of unsupervised exercise therapy for patients after EVT.

Material and Methods

A retrospective analysis was performed in 76 patients (93 limbs) with IC who underwent iliac EVT from 2012 to 2020 at our hospital. Maintenance of unsupervised exercise therapy was evaluated at 6 months after EVT. Long-term outcomes such as primary patency, clinically driven target lesion revascularization (CD-TLR), survival, and major adverse cardiovascular events (MACE) were compared between patients who continued (cET group) or discontinued (dET group) unsupervised exercise therapy.

Results

A total of 28 patients (37%) continued unsupervised exercise therapy until 6 months after EVT for an iliac lesion. There were no differences in patient background and procedural details between the cET and dET groups. The follow-up rate was 96% in a median follow-up period of 35 [25 – 42] months. The mean exercise time in the cET group was 52 ± 18 minutes daily, with a mean frequency of 5.8 ± 1.1 days per week. The median step count in the cET group was 5559 ± 2908 steps daily. At 3 years, the cET group had significantly higher rates for primary patency (97% vs 71%, P = .002), and freedom from CD-TLR (97% vs 79%, P = .007); and a tendency for higher survival (100% vs 94%, P = .074), and higher freedom from MACE (89% vs 73%, P = .12).

Conclusion

The findings of this study suggested superior long-term outcomes, including primary patency, freedom from CD-TLR, survival, and freedom from MACE, in patients who maintained continuous unsupervised exercise therapy after EVT.

Exercise Prescription Methods and Attitudes in Cardiac Rehabilitation: A NATIONAL SURVEY

PURPOSE

High-quality exercise training improves outcomes in cardiac rehabilitation (CR), but little is known about how most programs prescribe exercise. Thus, the aim was to describe how current CR programs prescribe exercise.

METHODS

We conducted a 33-item anonymous survey of CR program directors registered with the American Association of Cardiovascular and Pulmonary Rehabilitation. We assessed the time, mode, and intensity of exercise prescribed, as well as attitudes about maximal exercise testing and exercise prescription. Results were summarized using descriptive statistics. Open-ended responses were coded and quantitated thematically.

RESULTS

Of 1470 program directors, 246 (16.7%) completed the survey. In a typical session of CR, a median of 5, 35, 10, and 5 min was spent on warm-up, aerobic exercise, resistance training, and cooldown, respectively. The primary aerobic modality was the treadmill (55%) or seated dual-action step machine (40%). Maximal exercise testing and high-intensity interval training (HIIT) were infrequently reported (17 and 8% of patients, respectively). The most common method to prescribe exercise intensity was ratings of perceived exertion followed by resting heart rate +20-30 bpm, although 55 unique formulas for establishing a target heart rate or range (THRR) were reported. Moreover, variation in exercise prescription between staff members in the same program was reported in 40% of programs. Program directors reported both strongly favorable and unfavorable opinions toward maximal exercise testing, HIIT, and use of THRR.

CONCLUSIONS

Cardiac rehabilitation program directors reported generally consistent exercise time and modes, but widely divergent methods and opinions toward prescribing exercise intensity. Our results suggest a need to better study and standardize exercise intensity in CR.

Relation of a Maximal Exercise Test to Change in Exercise Tolerance During Cardiac Rehabilitation

The purpose of this study was to test the hypothesis that an individualized exercise training target heart rate (HR) based on a maximal graded exercise test (GXT) is associated with greater improvements in exercise tolerance during cardiac rehabilitation (CR) compared with no GXT. In this retrospective study, we identified patients who completed 9 to 36 visits of CR between 2001 and 2016, with a length of stay ≤18 weeks and a visit frequency of 1 to 3 days per week. Patients were grouped based on whether their exercise was guided by a target HR determined from a GXT. To assess the relation between GXT and change in exercise training metabolic equivalents of task (METs), we used generalized linear models adjusted for age, gender, race, referral reason, CR visits, CR frequency, METs at start, CR location, and year of participation. Out of 4,455 patients (37% female, 48% White, median age = 62 years), 53% were prescribed a target HR based on a GXT. Compared with no GXT, a GXT was associated with a significantly greater increase in covariate-adjusted METs during CR and percentage change from start (+0.44 METs [95% confidence interval [CI] 0.38 to 0.51] and +17% [95% CI 14% to 19%], respectively). In a sensitivity analysis limited to patients with 24 to 36 visits at ≥2 days per week (n = 1,319), a GXT was associated with a significantly greater increase in covariate-adjusted exercise training METs (+0.51 [95% CI 0.36 to 0.66]; +19% [95% CI 13% to 24%]). In conclusion, to maximize the potential increase in exercise capacity during CR, patients should undergo a GXT to determine an individualized exercise training target HR.

Exercise duration: Independent effects on acute physiologic responses and the need for an individualized prescription

An individualization of exercise prescription is implemented mainly in terms of intensity but not for duration. To survey the need for an individualized exercise duration prescription, we investigated acute physiologic responses during constant‐load exercise of maximal duration (t_max) and determined so‐called duration thresholds. Differences between absolute (min) and relative terms (% t_max) of exercise duration were analyzed. Healthy young and trained male and female participants (n = 11) performed an incremental exercise test and one t_max constant‐load exercise test at a target intensity of 10% of maximal power output below the second lactate turn point (LTP₂). Blood lactate, heart rate, and spirometric data were measured during all tests. t_max was markedly different across subjects (69.6 ± 14.8 min; range: 40–90 min). However, distinct duration phases separated by duration thresholds (DTh) were found in most measured variables. These duration thresholds (except DTh1) were significantly related to t_max (DTh2: r² = 0.90, p < 0.0001; DTh3: r² = 0.98, p < 0.0001) and showed substantial interindividual differences if expressed in absolute terms (DTh2: 24.8 ± 6.0 min; DTh3: 47.4 ± 10.6 min) but not in relative terms (DTh2: 35.4 ± 2.7% t_max; DTh3: 67.9 ± 2.4% t_max). Our data showed that (1) maximal duration was individually different despite the same relative intensity, (2) duration thresholds that were related to t_max could be determined in most measured variables, and (3) duration thresholds were comparable between subjects if expressed in relative terms. We therefore conclude that duration needs to be concerned as an independent variable of exercise prescription.

Exercise training in cardiac rehabilitation: Setting the right intensity for optimal benefit

Cardiac rehabilitation (CR) programs are recommended standard-of-care by all major cardiovascular medicine professional organizations. Exercise training is the cornerstone for CR, with aerobic training being the primary form of training. The benefits of exercise training are multiple; however, improved cardiorespiratory fitness is of utmost importance. Moderate-intensity continuous training, supplemented with resistance training, has traditionally been the most common form of exercise training in CR. This review discusses the role of aerobic exercise training in CR and the importance of effective and personalized exercise prescription for optimized results. We also focus on the benefits and utility of high-intensity interval training across different clinical populations commonly seen in the CR setting.

Cross-Validation of Predictive Equation for Cardiorespiratory Fitness by Modified Shuttle Walk Test in Adults with Schizophrenia: A Secondary Analysis of the CORTEX-SP Study

Cardiorespiratory fitness (CRF) can be direct or estimated from different field tests. The Modified Shuttle Walk Test (MSWT) is suitable for all levels of function, allowing a peak response to be elicited. Therefore, we aimed (1) to validate the equation presented in the original study by Singh et al. for evaluating the relationship between MSWT with peak oxygen uptake (VO_2peak) in adults with schizophrenia (SZ), (2) to develop a new equation for the MSWT to predict VO_2peak, and (3) to validate the new equation. Participants (N = 144, 41.3 ± 10.2 years old) with SZ performed a direct measurement of VO_2peak through a cardiopulmonary exercise test and the MSWT. A new equation incorporating resting heart rate, body mass index, and distance from MSWT (R² = 0.617; adjusted R² = 0.60; p < 0.001) performs better than the Singh et al. equation (R² = 0.57; adjusted R² = 0.57; p < 0.001) to estimate VO_2peak for the studied population. The posteriori cross-validation method confirmed the model’s stability (R² = 0.617 vs. 0.626). The findings of the current study support the validity of the new regression equation incorporating resting heart rate, body mass index, and distance from MSWT to predict VO_2peak for assessment of CRF in people with SZ.

Identification of Non-Invasive Exercise Thresholds: Methods, Strategies, and an Online App

During incremental exercise, two thresholds may be identified from standard gas exchange and ventilatory measurements. The first signifies the onset of blood lactate accumulation (the lactate threshold, LT) and the second the onset of metabolic acidosis (the respiratory compensation point, RCP). The ability to explain why these thresholds occur and how they are identified, non-invasively, from pulmonary gas exchange and ventilatory variables is fundamental to the field of exercise physiology and requisite to the understanding of core concepts including exercise intensity, assessment, prescription, and performance. This review is intended as a unique and comprehensive theoretical and practical resource for instructors, clinicians, researchers, lab technicians, and students at both undergraduate and graduate levels to facilitate the teaching, comprehension, and proper non-invasive identification of exercise thresholds. Specific objectives are to: (1) explain the underlying physiology that produces the LT and RCP; (2) introduce the classic non-invasive measurements by which these thresholds are identified by connecting variable profiles to underlying physiological behaviour; (3) discuss common issues that can obscure threshold detection and strategies to identify and mitigate these challenges; and (4) introduce an online resource to facilitate learning and standard practices. Specific examples of exercise gas exchange and ventilatory data are provided throughout to illustrate these concepts and a novel online application tool designed specifically to identify the estimated LT (θ_LT) and RCP is introduced. This application is a unique platform for learners to practice skills on real exercise data and for anyone to analyze incremental exercise data for the purpose of identifying θ_LT and RCP.

Oxygen Saturation Behavior by Pulse Oximetry in Female Athletes: Breaking Myths

The myths surrounding women’s participation in sport have been reflected in respiratory physiology. This study aims to demonstrate that continuous monitoring of blood oxygen saturation during a maximal exercise test in female athletes is highly correlated with the determination of the second ventilatory threshold (VT2) or anaerobic threshold (AnT). The measurements were performed using a pulse oximeter during a maximum effort test on a treadmill on a population of 27 healthy female athletes. A common behavior of the oxygen saturation evolution during the incremental exercise test characterized by a decrease in saturation before the aerobic threshold (AeT) followed by a second significant drop was observed. Decreases in peripheral oxygen saturation during physical exertion have been related to the athlete’s physical fitness condition. However, this drop should not be a limiting factor in women’s physical performance. We found statistically significant correlations between the maximum oxygen uptake and the appearance of the ventilatory thresholds (VT1 and VT2), the desaturation time, the total test time, and between the desaturation time and the VT2. We observed a relationship between the desaturation time and the VT2 appearance. Indeed, a linear regression model between the desaturation time and the VT2 appearance can predict 80% of the values in our sample. Besides, we suggest that pulse oximetry is a simple, fairly accurate, and non-invasive technique for studying the physical condition of athletes who perform physical exertion.

High-intensity interval training versus progressive high-intensity circuit resistance training on endothelial function and cardiorespiratory fitness in heart failure: A preliminary randomized controlled trial

INTRODUCTION

Exercise training is strongly recommended as a therapeutic approach to treat individuals with heart failure. High-intensity exercise training modalities still controversial in this population. The study aims to preliminary assess the consequences of high-intensity exercise training modalities, aerobic interval training (HIIT) and progressive high circuit-resistance training (CRT), on primarily endothelial function and cardiorespiratory fitness, and secondly on muscle strength and physical performance in heart failure patients.

METHODS

This preliminary multicentric randomized controlled trial comprised 23 heart failure patients, aged 56 ± 10 years old, mainly New York Heart Association classification I and II (%), hemodynamically stable, who compromise at least 36 exercise sessions of a randomly assigned intervention (HIIT, CRT or control group). Endothelial function, cardiopulmonary exercise testing, muscle strength and physical performance were completed at baseline and post-intervention.

RESULTS

Although no effects on endothelial function; both HIIT and CRT modalities were able to produce a positive effect on [Formula: see text] peak (HIIT = +2.1±6.5, CRT = +3.0±4.2 and control group = -0.1± 5.3 mL/kg/min, time*group p-value<0,05) and METs (HIIT = +0.6±1.8, CRT = +0.9±1.2 and control group = 0±1.6, time*group p-value<0,05). Only HIIT increased isokinetic torque peak (HIIT = +8.8±55.8, CRT = 0.0±60.7 and control group = 1.6±57.6 Nm) matched p-value<0,05. Regarding the physical performance, the CRT modality reduced chair stand test completion time (HIIT = -0.7±3.1, CRT = -3.3±3.2 and control group = -0.3±2.5 s, matched p-value<0,05 and HIIT improved global physical performance(time*group p<0,05).

CONCLUSION

This preliminary study trends to indicate for the first time that high-intensity interval training promotes a jointly superior effect compared to progressive high intensity circuit-resistance training by improving cardiorespiratory fitness, muscular strength, and physical performance. Further research with larger cohort is necessary.

CLINICAL TRIAL REGISTRATION NUMBER

ReBEC RBR-668c8v.

ECG Ventricular Repolarization Dynamics during Exercise: Temporal Profile, Relation to Heart Rate Variability and Effects of Age and Physical Health

Periodic repolarization dynamics (PRD) is a novel electrocardiographic marker of cardiac repolarization instability with powerful risk stratification capacity for total mortality and sudden cardiac death. Here, we use a time-frequency analysis approach to continuously quantify PRD at rest and during exercise, assess its dependence on heart rate variability (HRV) and characterize the effects of age (young adults/middle-aged adults/older adults), body mass index (non-overweight/overweight) and cardiorespiratory fitness level (fit/unfit). Sixty-six male volunteers performed an exercise test. RR and dT variabilities (RRV, dTV), as well as the fraction of dT variability unrelated to RR variability, were computed based on time-frequency representations. The instantaneous LF power of dT (PdTV), representing the same concept as PRD, and of its RRV-unrelated component (PdTVuRRV) were quantified. dT angle was found to mostly oscillate in the LF band. Overall, 50-70% of PdTV was linearly unrelated to RRV. The onset of exercise caused a sudden increase in PdTV and PdTVuRRV, which returned to pre-exercise levels during recovery. Clustering analysis identified a group of overweight and unfit individuals with significantly higher PdTV and PdTVuRRV values at rest than the rest of the population. Our findings shed new light on the temporal profile of PRD during exercise, its relationship to HRV and the differences in PRD between subjects according to phenotypic characteristics.

Impact of β-Blockers on Heart Rate and Oxygen Uptake During Exercise and Recovery in Older Patients With Heart Failure With Preserved Ejection Fraction

PURPOSE

The study aimed to investigate the differences in oxygen uptake ((Equation is included in full-text article.)O2) and heart rate (HR) (at rest, submaximal exercise, peak exercise, and recovery) in patients with heart failure with preserved ejection fraction (HFpEF) with β-blockers (BB) or without BB treatment (NBB) and to analyze the relationship between HR reserve (HRresv) and peak (Equation is included in full-text article.)O2 ((Equation is included in full-text article.)O2peak) in BB and NBB.

METHODS

A total of 174 HFpEF patients (>65 yr; BB, n = 59; NBB, n = 115) were assessed with a cardiopulmonary exercise test to peak exertion using an incremental protocol. After 5 min of supine rest, HR and (Equation is included in full-text article.)O2 (HRrest, (Equation is included in full-text article.)O2rest) at submaximal exercise (HRsubmax, (Equation is included in full-text article.)O2submax), at peak exercise (HRpeak, (Equation is included in full-text article.)O2peak), at 1 min of passive recovery (HRrec1), HRresv (HRpeak- HRrest), and HR recovery (HRrecov = HRpeak- HRrec1) were evaluated.

RESULTS

Analysis showed that HRrest (66.0 ± 12.2 vs 69.7 ± 10.6 bpm), HRsubmax (91.7 ± 16.2 vs 98.6 ± 15.2 bpm), and HRrec1 (102.9 ± 18.9 vs 109.4 ± 16.9 bpm) were significantly lower (P ≤ .05) in BB than in NBB, respectively. However, there were no significant differences (P > .05) between the BB and the NBB for HRpeak, HRresv, HRrecov, (Equation is included in full-text article.)O2rest, (Equation is included in full-text article.)O2submax, and (Equation is included in full-text article.)O2peak. A significant relationship was found between HRresv and (Equation is included in full-text article.)O2peak values in both groups (BB, r = 0.52; NBB, r = 0.49, P < .001).

CONCLUSIONS

The nonsignificant differences in HRpeak, HRresv, HRrecov, or (Equation is included in full-text article.)O2 values between BB and NBB HFpEF patients, along with significant correlation between HRresv and (Equation is included in full-text article.)O2peak, suggest that these measures may have equal utility in prognostic and functional assessment as well as clinical applications, including the prescription of exercise, in elderly HFpEF patients.

Association between pulmonary oxygen uptake on-kinetics and acute cardiovascular responses to resistance exercise in patients with coronary artery disease: a preliminary study

[Purpose] This study aimed to examine whether pulmonary oxygen uptake on-kinetics at the onset of moderate-intensity exercise can predict acute cardiovascular responses to resistance exercise. [Participants and Methods] The association between pulmonary oxygen uptake on-kinetics and acute cardiovascular responses to a single resistance exercise session was investigated in seven patients with low-risk coronary artery disease who underwent revascularization through percutaneous coronary intervention. The participants performed a cardiopulmonary exercise test on a cycle ergometer and a single resistance exercise session at 30% of maximum voluntary contraction on a bilateral leg-extension machine 1 week after surgery. We measured the ventilatory anaerobic threshold and pulmonary oxygen uptake on-kinetics during the cardiopulmonary exercise test; left ventricular ejection fraction at rest; and heart rate, systolic blood pressure, and rate pressure product during the single resistance exercise session. [Results] Pulmonary oxygen uptake on-kinetics showed a positive association with the amount of increase in systolic blood pressure and rate pressure product during the single resistance exercise session, but had no association with the amount of increase in heart rate. Ventilatory anaerobic threshold and left ventricular ejection fraction were not associated with these parameters. [Conclusion] These data suggested that pulmonary oxygen uptake on-kinetics can be a useful evaluation index for predicting acute systolic blood pressure and rate pressure product responses to low-intensity resistance exercise 1 week after percutaneous coronary intervention in patients with low-risk coronary artery disease.

Functional Translation of Exercise Responses from Exercise Testing to Exercise Training: The Test of a Model

Exercise prescription based on exercise test results is complicated by the need to downregulate the absolute training intensity to account for cardiovascular drift in order to achieve a desired internal training load. We tested a recently developed generalized model to perform this downregulation using metabolic equivalents (METs) during exercise testing and training. A total of 20 healthy volunteers performed an exercise test to define the METs at 60, 70, and 80% of the heart rate (HR) reserve and then performed randomly ordered 30 min training bouts at absolute intensities predicted by the model to achieve these levels of training intensity. The training HR at 60 and 70% HR reserve, but not 80%, was significantly less than predicted from the exercise test, although the differences were small. None of the ratings of perceived exertion (RPE) values during training were significantly different than predicted. There was a strong overall correlation between predicted and observed HR (r = 0.88) and RPE (r = 0.52), with 92% of HR values within ±10 bpm and 74% of RPE values within ±1 au. We conclude that the generalized functional translation model is generally adequate to allow the generation of early absolute training loads that lead to desired internal training loads.

Prediction of Exercise Capacity and Training Prescription from the 6-Minute Walk Test and Rating of Perceived Exertion

Walking tests, such as the 6-min walk test (6MWT), are popular methods of estimating peak oxygen uptake (VO₂peak) in clinical populations. However, the strength of the distance vs. VO₂peak relationship is not strong, and there are no equations for estimating ventilatory threshold (VT), which is important for training prescription and prognosis. Since the 6MWT is often limited by walking mechanics, prediction equations that include simple additional predictors, such as the terminal rating of perceived exertion (RPE), hold the potential for improving the prediction of VO₂max and VT. Therefore, this study was designed to develop equations for predicting VO₂peak and VT from performance during the 6MWT, on the basis of walking performance and terminal RPE. Clinically stable patients in a cardiac rehabilitation program (N = 63) performed the 6MWT according to the American Thoracic Society guidelines. At the end of each walk, the subject provided their terminal RPE on a 6-20 Borg scale. Each patient also performed a maximal incremental treadmill test with respiratory gas exchange to measure VO₂peak and VT. There was a good correlation between VO₂peak and 6MWT distance (r = 0.80) which was improved by adding the terminal RPE in a multiple regression formula (6MWT + RPE, R² = 0.71, standard error of estimate, SEE = 1.3 Metabolic Equivalents (METs). The VT was also well correlated with walking performance, 6MWT distance (r = 0.80), and was improved by the addition of terminal RPE (6MWT + RPE, R² = 0.69, SEE = 0.95 METs). The addition of terminal RPE to 6MWT distance improved the prediction of maximal METs and METs at VT, which may have practical applications for exercise prescription.

Workload Accomplished in Phase III Cardiac Rehabilitation

Exercise training is an important component of clinical exercise programs. Although there are recognized guidelines for the amount of exercise to be accomplished (≥70,000 steps per week or ≥150 min per week at moderate intensity), there is virtually no documentation of how much exercise is actually accomplished in contemporary exercise programs. Having guidelines without evidence of whether they are being met is of limited value. We analyzed both the weekly step count and the session rating of perceived exertion (sRPE) of patients (n = 26) enrolled in a community clinical exercise (e.g., Phase III) program over a 3-week reference period. Step counts averaged 39,818 ± 18,612 per week, with 18% of the steps accomplished in the program and 82% of steps accomplished outside the program. Using the sRPE method, inside the program, the patients averaged 162.4 ± 93.1 min per week, at a sRPE of 12.5 ± 1.9 and a frequency of 1.8 ± 0.7 times per week, for a calculated exercise load of 2042.5 ± 1244.9 AU. Outside the program, the patients averaged 144.9 ± 126.4 min, at a sRPE of 11.8 ± 5.8 and a frequency of 2.4 ± 1.5 times per week, for a calculated exercise load of 1723.9 ± 1526.2 AU. The total exercise load using sRPE was 266.4 ± 170.8 min per week, at a sRPE of 12.6 ± 3.8, and frequency of 4.2 ± 1.1 times per week, for a calculated exercise load of 3359.8 ± 2145.9 AU. There was a non-linear relationship between steps per week and the sRPE derived training load, apparently attributable to the amount of non-walking exercise accomplished in the program. The results suggest that patients in a community clinical exercise program are achieving American College of Sports Medicine guidelines, based on the sRPE method, but are accomplishing less steps than recommended by guidelines.

The effect of cardiac rehabilitation on kinesiophobia in patients with coronary artery disease

Objectives

The aim of this study was to define the level of kinesiophobia in cardiac patients, to determine whether there was a positive change in kinesiophobia after an exercise based cardiac rehabilitation (CR), and to define the associated variables with the change in kinesiophobia.

Patients and methods

Between September 2017 and December 2018, a total of 98 patients (63 males, 35 females; mean age: 58±10.4 years; range, 36 to 78 years) diagnosed with coronary artery disease (CAD) were included in the study. The Tampa Scale for Kinesiophobia Heart (TSK-SV Heart) was used to measure kinesiophobia. The short form of the International Physical Activity Questionnaire (IPAQ) was applied to measure physical activity level. The Short Form 36 (SF-36) was used to measure health-related quality of life (HRQoL). After CR, kinesiophobia was reevaluated.

Results

A high level of kinesiophobia was present in 74.5% of the patients. The mean TSK-SV heart score was 41.4±6.2. After CR, 34.6% of the patients had a high level of kinesiophobia (p<0.001). The patients with a high level of kinesiophobia were physically more inactive than those with a low level of kinesiophobia (p=0.001) and HRQoL scores were significantly lower (p<0.05).

Conclusion

Kinesiophobia is quite common in patients with CAD. Aerobic exercise capacity and physical activity levels are lower in patients with a high level of kinesiophobia, compared to those with a low level of kinesiophobia. After an exercise-based CR program, kinesiophobia significantly reduces.

Renal Rehabilitation: Exercise Intervention and Nutritional Support in Dialysis Patients

With the growing number of dialysis patients with frailty, the concept of renal rehabilitation, including exercise intervention and nutrition programs for patients with chronic kidney disease (CKD), has become popular recently. Renal rehabilitation is a comprehensive multidisciplinary program for CKD patients that is led by doctors, rehabilitation therapists, diet nutritionists, nursing specialists, social workers, pharmacists, and therapists. Many observational studies have observed better outcomes in CKD patients with more physical activity. Furthermore, recent systematic reviews have shown the beneficial effects of exercise intervention on exercise tolerance, physical ability, and quality of life in dialysis patients, though the beneficial effect on overall mortality remains unclear. Nutritional support is also fundamental to renal rehabilitation. There are various causes of skeletal muscle loss in CKD patients. To prevent muscle protein catabolism, in addition to exercise, a sufficient supply of energy, including carbohydrates, protein, iron, and vitamins, is needed. Because of decreased digestive function and energy loss due to dialysis treatment, dialysis patients are recommended to ingest 1.2-fold more protein than the regular population. Motivating patients to join in activities is also an important part of renal rehabilitation. It is essential for us to recognize the importance of renal rehabilitation to maximize patient satisfaction.

The Benefits of High-Intensity Interval Training on Cognition and Blood Pressure in Older Adults With Hypertension and Subjective Cognitive Decline: Results From the Heart & Mind Study

Background: The impact of exercise on cognition in older adults with hypertension and subjective cognitive decline (SCD) is unclear.

Objectives: We determined the influence of high-intensity interval training (HIIT) combined with mind-motor training on cognition and systolic blood pressure (BP) in older adults with hypertension and SCD.

Methods: We randomized 128 community-dwelling older adults [age mean (SD): 71.1 (6.7), 47.7% females] with history of hypertension and SCD to either HIIT or a moderate-intensity continuous training (MCT) group. Both groups received 15 min of mind-motor training followed by 45 min of either HIIT or MCT. Participants exercised in total 60 min/day, 3 days/week for 6 months. We assessed changes in global cognitive functioning (GCF), Trail-Making Test (TMT), systolic and diastolic BP, and cardiorespiratory fitness.

Results: Participants in both groups improved diastolic BP [F_{(1, 87.32)} = 4.392, p = 0.039], with greatest effect within the HIIT group [estimated mean change (95% CI): −2.64 mmHg, (−4.79 to −0.48), p = 0.017], but no between-group differences were noted (p = 0.17). Both groups also improved cardiorespiratory fitness [F_{(1, 69)} = 34.795, p < 0.001], and TMT A [F_{(1, 81.51)} = 26.871, p < 0.001] and B [F_{(1, 79.49)} = 23.107, p < 0.001]. There were, however, no within- or between-group differences in GCF and systolic BP at follow-up.

Conclusion: Despite improvements in cardiorespiratory fitness, exercise of high- or moderate-intensity, combined with mind-motor training, did not improve GCF or systolic BP in individuals with hypertension and SCD.

Clinical Trial Registration:ClinicalTrials.gov (NCT03545958).

Exercise Evaluation and Prescription

Ever since the farm boy, Milo of Crotone, lifted a growing bullock every day, to become the strongest man in the world, and six-time champion of the ancient Olympic Games, we have known about the principle of progression of exercise training [...].

Prognostic effects of cardiovascular rehabilitation: facts and myths

Since CR was introduced, studies have been carried out to discover the effect of CRHPs on cardiovascular morbidity and mortality and on heart-disease patients' quality of life. The first meta-analyses showed improvement in cardiovascular morbidity and mortality, although the studies were conducted in the coronary pre-reperfusion era, before the generalized use in secondary prevention of drugs such as statins, beta-blockers, or renin-angiotensin-system inhibitors, which have produced a decrease in cardiovascular mortality. In Europe, analyzing 25 studies with more than 200,000 patients. It concluded that, in spite of the great heterogeneity of the programs, CR clearly decreases mortality after ACS. Nevertheless, a strategy of CRHP standardization and evaluation is needed. In 2017, a study was carried out in our hospital to evaluate the effectiveness of multidisciplinary CRHP intervention on cardiovascular morbidity and mortality, recurrence of cardiovascular events, the control of RFCV and lifestyle changes in patients after ACS. A total of 442 patients were included who had presented an acute cardiovascular event in the previous six months; 306 patients from the CR group and 136 others with standard cardiology follow-up were used as controls. 405 patients completed follow-up for a median of 60 months. Compared to the usual treatments in cardiology, the patients who underwent CRHPs presented fewer readmissions for cardiovascular reasons (17% vs. 43.38%, P<0.001), fewer major cardiovascular events (11.9% vs. 27.2%, P<0.001) and new revascularizations (9.3% vs. 21.32%, P=0.001), with lower cardiovascular mortality (0 vs. 2.2%, P=0.014). It also led to better control of the RFCV (66% vs. 19.85%, P<0.001) and favored lifestyle changes in these patients (91% vs. 61%, P<0.001). Therefore, in our setting, the performance of CRHPs was shown to be effective in reducing cardiovascular morbidity and mortality and in the secondary prevention of coronary patients.

Adherence to High-Intensity Interval Training in Cardiac Rehabilitation: A REVIEW AND RECOMMENDATIONS

PURPOSE

High-intensity interval training (HIIT) is gaining popularity as a training approach for patients attending cardiac rehabilitation (CR). While the literature has focused on the efficacy of HIIT for improving cardiorespiratory fitness (CRF), particularly when compared with moderate intensity exercise, less emphasis has been placed on adherence to HIIT. The aim of this review was to summarize the current literature regarding adherence to HIIT in CR patients with coronary artery disease.

REVIEW METHODS

A review identified 36 studies investigating HIIT in CR patients with coronary artery disease. Methods and data were extracted for exercise or training adherence (to attendance, intensity, and duration), feasibility of protocols, and CRF. The review summarizes reporting of adherence; adherence to HIIT and comparator/s; the influence of adherence on changes in CRF; and feasibility of HIIT.

SUMMARY

Adherence to the attendance of HIIT sessions was high and comparable with moderate-intensity exercise. However, adherence to the intensity and duration of HIIT was variable and underreported, which has implications for determining the treatment effect of the exercise interventions being compared. Furthermore, additional research is needed to investigate the utility of home-based HIIT and long-term adherence to HIIT following supervised programs. This review provides recommendations for researchers in the measurement and reporting of adherence to HIIT and other exercise interventions to facilitate a sufficient and consistent approach for future studies. This article also highlights strategies for clinicians to improve adherence, feasibility, and enjoyment of HIIT for their patients.

Sympathetic neural responses in heart failure during exercise and after exercise training

The sympathetic nervous system coordinates the cardiovascular response to exercise. This regulation is impaired in both experimental and human heart failure with reduced ejection fraction (HFrEF), resulting in a state of sympathoexcitation which limits exercise capacity and contributes to adverse outcome. Exercise training can moderate sympathetic excess at rest. Recording sympathetic nerve firing during exercise is more challenging. Hence, data acquired during exercise are scant and results vary according to exercise modality. In this review we will: (1) describe sympathetic activity during various exercise modes in both experimental and human HFrEF and consider factors which influence these responses; and (2) summarise the effect of exercise training on sympathetic outflow both at rest and during exercise in both animal models and human HFrEF. We will particularly highlight studies in humans which report direct measurements of efferent sympathetic nerve traffic using intraneural recordings. Future research is required to clarify the neural afferent mechanisms which contribute to efferent sympathetic activation during exercise in HFrEF, how this may be altered by exercise training, and the impact of such attenuation on cardiac and renal function.

A "Step-Ramp-Step" Protocol to Identify the Maximal Metabolic Steady State

The oxygen uptake (V[Combining Dot Above]O2) at the respiratory compensation point (RCP) closely identifies with the maximal metabolic steady state. However, the power output (PO) at RCP cannot be determined from contemporary ramp-incremental exercise protocols.

PURPOSE

This study aimed to test the efficacy of a "step-ramp-step" (SRS) cycling protocol for estimating the PO at RCP and the validity of RCP as a maximal metabolic steady-state surrogate.

METHODS

Ten heathy volunteers (5 women; age: 30 ± 7 yr; V[Combining Dot Above]O2max: 54 ± 6 mL·kg·min) performed in the following series: a moderate step transition to 100 W (MOD), ramp (30 W·min), and after 30 min of recovery, step transition to ~50% POpeak (HVY). Ventilatory and gas exchange data from the ramp were used to identify the V[Combining Dot Above]O2 at lactate threshold (LT) and RCP. The PO at LT was determined by the linear regression of the V[Combining Dot Above]O2 versus PO relationship after adjusting ramp data by the difference between the ramp PO at the steady-state V[Combining Dot Above]O2 from MOD and 100 W. Linear regression between the V[Combining Dot Above]O2-PO values associated with LT and HVY provided, by extrapolation, the PO at RCP. Participants then performed 30-min constant-power tests at the SRS-estimated RCP and 5% above this PO.

RESULTS

All participants completed 30 min of constant-power exercise at the SRS-estimated RCP achieving steady-state V[Combining Dot Above]O2 of 3176 ± 595 mL·min that was not different (P = 0.80) from the ramp-identified RCP (3095 ± 570 mL·min) and highly consistent within participants (bias = -26 mL·min, r = 0.97, coefficient of variation = 2.3% ± 2.8%). At 5% above the SRS-estimated RCP, four participants could not complete 30 min and all, but two exhibited non-steady-state responses in blood lactate and V[Combining Dot Above]O2.

CONCLUSIONS

In healthy individuals cycling at their preferred cadence, the SRS protocol and the RCP are capable of accurately predicting the PO associated with maximal metabolic steady state.

25 Years of Session Rating of Perceived Exertion: Historical Perspective and Development

The session rating of perceived exertion (sRPE) method was developed 25 years ago as a modification of the Borg concept of rating of perceived exertion (RPE), designed to estimate the intensity of an entire training session. It appears to be well accepted as a marker of the internal training load. Early studies demonstrated that sRPE correlated well with objective measures of internal training load, such as the percentage of heart rate reserve and blood lactate concentration. It has been shown to be useful in a wide variety of exercise activities ranging from aerobic to resistance to games. It has also been shown to be useful in populations ranging from patients to elite athletes. The sRPE is a reasonable measure of the average RPE acquired across an exercise session. Originally designed to be acquired ∼30 minutes after a training bout to prevent the terminal elements of an exercise session from unduly influencing the rating, sRPE has been shown to be temporally robust across periods ranging from 1 minute to 14 days following an exercise session. Within the training impulse concept, sRPE, or other indices derived from sRPE, has been shown to be able to account for both positive and negative training outcomes and has contributed to our understanding of how training is periodized to optimize training outcomes and to understand maladaptations such as overtraining syndrome. The sRPE as a method of monitoring training has the advantage of extreme simplicity. While it is not ideal for the precise recording of the details of the external training load, it has large advantages relative to evaluating the internal training load.

Clinical, physical, physiological, and cardiovascular risk patterns of adults with schizophrenia: CORTEX-SP study: Characterization of adults with schizophrenia

Schizophrenia (SP) is a severe mental illness with high rates of premature morbidity and mortality, associated with an unhealthy lifestyle and the side effects of drug treatment. The aims of the study were: 1) to determine some key physical, physiological and biochemical markers of health status, including sleep quality, in adults (42±10 yr) with SP (n=126), 2) to estimate cardiovascular risk (CVR), and 3) to compare all studied variables with a healthy control (HC) population (n=30). Assessment was based on body composition, blood pressure, cardiorespiratory condition, sleep quality with triaxial accelerometry for eight days and biochemical analysis. Participants with SP showed a cardiovascular risk profile including "overweight metabolically abnormal", low cardiorespiratory fitness, and impairment of ventilatory efficiency. Although individuals with SP slept more compared to HC, similar sleep efficiency was shown by both groups, but with significantly higher levels of wake after sleep onset by SP. The assessment of CVR revealed significantly higher values in SP (moderate risk) compared to HC (low risk) regardless of the estimation system. The identification of specific clinical, physical, and physiological CVR profiles in SP illness compared to healthy people strongly suggests targeting a comprehensive approach including non-pharmacological interventions. Clinical Trials.gov identifier, NCT03509597. Date of registration: April 26^th, 2018.

Impact on Health-Related Quality of Life after Different Aerobic Exercise Programs in Physically Inactive Adults with Overweight/Obesity and Primary Hypertension: Data from the EXERDIET-HTA Study

Primary hypertension (HTN) and obesity are associated with a worse health-related quality of life (QoL). This research was carried out to analyze the health-related QoL measurements in a physically inactive and obese population with HTN (n = 253) in comparison to a HEALTHY sample (n = 30), to determine the HTN sample changes in QoL following different (high-volume moderate-intensity continuous training, high-volume high-intensity interval training (HIIT), low-volume HIIT) 16-week supervised aerobic exercise training (ExT) programs compared to attention control, and to assess the differences in QoL variables between the different ExT programs. The SF-36 questionnaire was used to assess health-related QoL. At baseline, HTN showed lower scores (p < 0.05) in physical function (88.6 vs. 99.2), general health (63.3 vs. 82.4), vitality (58.2 vs. 68.7), social functioning (88.5 vs. 95.2), and mental health (76.1 vs. 81.8) compared to HEALTHY. Following intervention, all HTN subgroups showed higher (p < 0.05) vitality, but physical functioning and general health significantly improved only in the ExT groups, with even better values in general health for both HIIT subgroups. Only the low-volume HIIT showed positive changes (p < 0.05) in social functioning (∆ = 6.9%) and mental health (∆ = 6.4%) domains after the intervention. These results highlight the important role of supervised exercise in improving physical and psychological health.

Considering the Feasibility, Tolerability, and Safety of High-Intensity Interval Training as a Novel Treatment for Patients With Intermittent Claudication

PURPOSE

This study assessed the feasibility, tolerability, safety, and potential efficacy of a novel, 6-wk, high-intensity interval training (HIIT) program for patients with intermittent claudication (IC).

METHODS

Patients referred to a usual-care supervised exercise program were invited to undertake a HIIT program. All recruited patients performed a baseline cardiopulmonary exercise test (CPX) to inform their exercise prescription. HIIT involved 10, 1-min high-intensity cycling intervals interspersed with 1-min recovery intervals, performed 3 d/wk for 6 wk. Outcomes included feasibility, tolerability, safety, walking distance, and quality of life.

RESULTS

A total of 144 patients with IC were referred, 95 met initial eligibility criteria (66%) and 30 (32%) were recruited for HIIT, of which 15 (50%) completed. Of the recruited patients, 90% were on optimal medical therapy and 40% had concomitant cardiac, cerebrovascular, and/or respiratory disease. Patients who completed the program attended 100% of the sessions and one serious adverse event was recorded. Improvements in walking distances and quality of life were observed. Following recruitment of the first 20 patients, the inclusion criteria were refined on the basis of CPX, leading to improved completion rates.

CONCLUSIONS

This study provides preliminary findings indicating that patients with IC can complete a short-term HIIT program. We provide very early evidence that HIIT may be safe and well-tolerated. In addition, walking distances seem to improve following HIIT. After a small change in the exclusion criteria, the intervention and inclusion/exclusion criteria now seem appropriate for this population, meaning further research to evaluate HIIT in patients with IC is warranted.

Effectiveness of continuous unsupervised exercise therapy after above-knee femoropopliteal bypass

OBJECTIVE

Exercise therapy has acceptable outcomes for patients with intermittent claudication, although few reports exist regarding the results of continuous exercise therapy after surgical reconstruction for intermittent claudication. This study aimed to analyze the long-term outcomes of unsupervised exercise therapy for patients after above-knee femoropopliteal bypass.

MATERIAL AND METHODS

We retrospectively analyzed 69 patients (69 limbs, 69 grafts) who underwent above-knee femoropopliteal bypass from April 2009 to March 2018 in our hospital. At six months after above-knee femoropopliteal bypass, we evaluated the maintenance of unsupervised exercise therapy. Patients who continued unsupervised exercise therapy or discontinued unsupervised exercise therapy were assessed via 1:1 propensity matching. Long-term outcomes such as patency, survival, and major adverse cardiovascular events were compared between the groups after matching. We also analyzed the maintaining rate of unsupervised exercise therapy in a study cohort.

RESULTS

Twenty-nine (42%) patients continued unsupervised exercise therapy until six months after above-knee femoropopliteal bypass. The discontinued unsupervised exercise therapy had higher proportions of female sex (p = 0.015) and cerebrovascular disease (p = 0.025) than did the continued unsupervised exercise therapy. The mean follow-up period was 65 ± 36 months. After propensity matching, the rates of the following factors were significantly higher in the continued unsupervised exercise therapy than in the discontinued unsupervised exercise therapy: primary patency (97% vs. 61%, p = 0.0041), secondary patency (100% vs. 69%, p = 0.0021), and freedom from major adverse cardiovascular events (61% vs. 24%, p = 0.0071) at five years. Both groups had a similar survival rate. The maintaining rate of unsupervised exercise therapy in the study cohort was 44% at six months, 41% at one year, 36% at three years, 25% at five years, and 25% at seven years.

CONCLUSION

The findings of this study suggested superior long-term outcomes, including graft patency and freedom from major adverse cardiovascular events, with unsupervised exercise therapy after open bypass than with the usual therapy. Unsupervised exercise therapy may be recommended for the patients after open bypass.

Long-Term Results of Distal Bypass for Intermittent Claudication

BACKGROUND

Distal bypass (DB) is the optimal treatment for patients with critical limb ischemia (CLI). However, effectiveness of DB for patients with intermittent claudication (IC) remains uncertain. This study aimed to analyze long-term results of DB for IC patients (IC-DB) compared with those of DB for CLI patients (CLI-DB).

METHODS

Patients undergoing DB from January 2009 to July 2018 at a single institution were retrospectively reviewed. Operative details, primary and secondary patency, amputation free survival rate (AFS), and long-term exercise capacity using Barthel index were analyzed.

RESULTS

Out of 302 DB (245 patients), 49 IC-DB were performed in 43 patients: 38 males, mean age 70.3 ± 8.0 years, diabetes mellitus 51%, chronic renal failure with hemodialysis 7%. The Great saphenous vein was used in 47 limbs, the small saphenous vein in 1, and the arm vein in 1. These grafts were bypassed in a non-reversed fashion for 35 limbs, in an in-situ fashion in 9, and in a reversed fashion in 5. The mean operative time was 173 min. The mean follow-up was 25 ± 26 months. Primary and secondary patency of IC-DB was 79% and 94% at 1 year, 71% and 90% at 3 years, 65% and 90% at 5 years, which were significantly higher than those of CLI-DB (primary patency: P = .007, secondary patency: P = .025). AFS of IC-DB and CLI-DB was 100% and 77% at 1 year, 93% and 52% at 3 years, and 90% and 43% at 5 years (IC-DB vs. CLI-DB, p < .0001). Barthel index of IC-DB unchanged at discharge (median 100) and at the last visit (median 100), showing daily activity was maintained adequately.

CONCLUSIONS

DB could offer a promising approach for patients with IC because of durable graft patency, acceptable AFS, and maintenance of daily activity.

Generalized Approach to Translating Exercise Tests and Prescribing Exercise

Although there is evidence supporting the benefit of regular exercise, and recommendations about exercise and physical activity, the process of individually prescribing exercise following exercise testing is more difficult. Guidelines like % heart rate (HR) reserve (HRR) require an anchoring maximal test and do not always provide a homogenous training experience. When prescribing HR on the basis of % HRR, rating of perceived exertion or Talk Test, cardiovascular/perceptual drift during sustained exercise makes prescription of the actual workload difficult. To overcome this issue, we have demonstrated a strategy for "translating" exercise test responses to steady state exercise training on the basis of % HRR or the Talk Test that appeared adequate for individuals ranging from cardiac patients to athletes. However, these methods depended on the nature of the exercise test details. In this viewpoint, we combine these data with workload expressed as Metabolic Equivalent Task (METs). We demonstrate that there is a regular stepdown between the METs during training to achieve the same degree of homeostatic disturbance during testing. The relationship was linear, was highly-correlated (r = 0.89), and averaged 71.8% (Training METs/Test METs). We conclude that it appears possible to generate a generalized approach to correctly translate exercise test responses to exercise training.

Validity of the Talk Test as a Method to Estimate Ventilatory Threshold and Guide Exercise Intensity in Cardiac Patients

PURPOSE

To determine the relationship between the Talk Test (TT) and ventilatory threshold (VT) in patients with cardiac disease and to compare the TT with exercise intensity guidelines.

METHODS

Twenty cardiac patients, aged 65 ± 8.5 yr, performed 2 exercise tests with identical ramp protocols on a cycle ergometer on the same day. One test was a submaximal effort to assess exercise intensity using the TT. The other was a cardiopulmonary exercise test using breath-by-breath gas analysis to identify VT and cardiorespiratory fitness.

RESULTS

Oxygen uptake and workload at the last positive stage (TTpos) was significantly lower than at VT. and workload at the equivocal stage (TTeq) and the first negative stage (TTneg) were not significantly different from VT, but limits of agreement (LoA) were wide. There was no significant difference in heart rate (HR) at TTpos and TTeq compared with VT, but HR at Tneg was significantly higher. The correlations between the TT and VT ranged from 0.37 to 0.60. Intensity at the different TT stages ranged from 58-77% of . All TT stages were within intensity guidelines of 40-80% of .

CONCLUSION

Although no significant differences were found in and workload for TTeq and TTneg when compared with VT, LoA demonstrated wide ranges, suggesting poor individual correspondence. The different stages of the TT can be used as a practical method to guide exercise intensity in patients with cardiac disease.

Long-Term Effects in the EXERDIET-HTA Study: Supervised Exercise Training vs. Physical Activity Advice

Purpose: To determine whether improvements in cardiorespiratory fitness (CRF), blood pressure (BP) and body composition previously seen after a 16-week exercise intervention (POST) with hypocaloric diet are maintained following six months (6M) of unsupervised exercise time. Methods: Overweight/obese, physically inactive participants with primary hypertension (HTN) (n = 190) were randomly assigned into an attention control group (physical activity recommendations) or one of three supervised exercise groups. After POST, all participants received diet and physical activity advice for the following 6M but no supervision. All anthropometric and physiological measurements were taken pre and post the 16-week supervised intervention period, as well as after 6M of no supervision. Results: After 6M: 1) body mass (BM) (Δ = 2.5%) and waist circumference (Δ = 1.8%) were higher (P < .005) than POST, but lower (P < .005) than pre-intervention (BM, Δ = -5.1%; waist circumference, Δ = -4.7%), with high-volume and high-intensity interval training group revealing a higher BM reduction (Δ = -6.4 kg) compared to control group (Δ = -3.5 kg); 2) BP variables were higher (P < .001) compared to POST with no change from pre-intervention; and 3) CRF was higher compared to pre-intervention (Δ = 17.1%, P < .001) but lower than POST (Δ = -5.7%, P < .001). Conclusions: When an overweight/obese population with HTN attains significant improvements in cardiometabolic health POST intervention with diet restriction, there is a significant reduction following 6M when exercise and diet supervision is removed, and only recommendations were applied. These results suggest the need for a regular, systematic and supervised diet and exercise programs to avoid subsequent declines in cardiometabolic health.

Lack of Cited Evidence Underpinning Recommendations for Objective Assessment of Cardiovascular Function to Inform Exercise Prescription: A Systematic Review

BACKGROUND

The effectiveness of exercise in managing cardiovascular (CV) health and function is well established. Less clear is the process for optimising the safety and efficacy of an intervention, particularly how objective assessments might inform this process.

OBJECTIVE

The aim of this review was to investigate the cited evidence underpinning recommendations for assessing CV function to inform the safe and effective prescription of exercise in populations with established CV disease, as published in documents to guide practice authored by prominent organisations in cardiology and sports medicine.

METHODS

A systematic review of position statements and guiding documents on exercise prescription for CV health was conducted. Included documents were published between 1997 and 2016.

RESULTS

Following removal of duplicates, 3158 documents were considered, with full-text screening required for 334. Twenty-seven documents were included which provided 106 individual recommendations for specific objective assessments. Of the total number of recommendations, 60% had no accompanying citation and 28% of recommendations provided citations that did not directly support the statement made. Additionally, 52% of included documents did not state the methods of document development. That is, it was not clear if there was a literature review and/or expert consensus that was used to form recommendations included within.

CONCLUSION

Almost no cited evidence underpinning the extracted recommendations from the included guiding documents, nor any acknowledgement of this deficiency was established. There were limited explanations found for the methods involved in developing such guiding documents.

Lactate Equivalent for Maximal Lactate Steady State Determination in Soccer

Purpose: The association between an overlooked classical Lactate Threshold (LT), named "Minimum Lactate Equivalent" (LE_min), with Maximal Lactate Steady State (MLSS) has been recently described with good MLSS prediction results in endurance-trained runners. This study aimed to determine the applicability of LE_min to predict MLSS in lower aerobic-conditioned individuals compared to well-established blood lactate-related thresholds (BLTs). Method: Fifteen soccer players [velocity at MLSS (MLSS_V) 13.2 ± 1.0 km·h^-1; coefficient of variation (CV) 7.6%] conducted a submaximal discontinuous incremental running test to determine BLTs and 3-6 constant velocity running tests to determine MLSS_V. Results: LE_min did not differ from conventional LTs (p > .05) and was 24% lower than MLSS (p < .001; ES: 3.26). Among LTs, LE_min best predicted MLSS_V (r = 0.83; p < .001; SEE = 0.59 km·h^-1). There was no statistical difference between MLSS and estimated MLSS using LE_min prediction formula (p = .99; ES: 0.001). Mean bias and limits of agreement were 0.00 ± 0.58 km·h^-1 and ±1.13 km·h^-1, respectively. LE_min best predicted MLSS_V (r = 0.92; p < .001; SEE = 0.54 km·h^-1) in the pooled data of soccer players and endurance-trained runners of the previous study (n = 28; MLSS_V range 11.2-16.5 km·h^-1; CV 9.8%). Conclusion: Results support LE_min to be one of the best single predictors of MLSS. This study is the sole study providing specific operational regression equations to estimate the impractical gold standard MLSS_V in soccer players by means of a BLT measured during a submaximal single-session test.

Progression of Exercise Training in Early Outpatient Cardiac Rehabilitation: AN OFFICIAL STATEMENT FROM THE AMERICAN ASSOCIATION OF CARDIOVASCULAR AND PULMONARY REHABILITATION

Aerobic and resistance exercise training is a cornerstone of early outpatient cardiac rehabilitation (CR) and provides impressive benefits for patients. The components of the exercise prescription for patients with cardiovascular diseases are provided in guideline documents from several professional organizations and include frequency (how many sessions per week); intensity (how hard to exercise); time (duration of the exercise training session); type (modalities of exercise training); volume (the total amount or dose of exercise); and progression (the rate of increasing the dose of exercise). The least discussed, least appreciated, and most challenging component of the exercise prescription for CR health care professionals is the rate of progression of the dose of exercise. One reason for this observation is the heterogeneity of patients who participate in CR. All components of the exercise prescription should be developed specifically for each individual patient. This statement provides an overview of the principles of exercise prescription for patients in CR with special emphasis on the rate of progression. General recommendations for progression are given and patient case examples are provided to illustrate the principles of progression in exercise training.

The influence of protocol design on the identification of ventilatory thresholds and the attainment of peak physiological responses during synchronous arm crank ergometry in able-bodied participants

Purpose

To examine the effects of stage duration on power output (PO), oxygen uptake (VO₂), and heart rate (HR) at peak level and ventilatory thresholds during synchronous arm crank ergometry.

Methods

Nineteen healthy participants completed a ramp, 1-min stepwise, and 3-min stepwise graded arm crank exercise test. PO, VO_2, and HR at the first and second ventilatory threshold (VT1, VT2) and peak level were compared among the protocols: a repeated measures analysis of variance was performed to test for systematic differences, while intraclass correlation coefficients (ICC) and Bland–Altman plots were calculated to determine relative and absolute agreement.

Results

Systematic differences among the protocols were found for PO at VT1, VT2, and peak level. At peak level, PO differed significantly among all protocols (ramp: 115 ± 37 W; 1-min stepwise: 108 ± 34 W; 3-min stepwise: 94 ± 31 W, p ≤ 0.01). No systematic differences for HR or VO₂ were found among the protocols. VT1 and VT2 were identified at 52% and 74% of VO₂peak, respectively. The relative agreement among protocols varied (ICC 0.02–0.97), while absolute agreement was low with small-to-large systematic error and large random error.

Conclusions

PO at VTs and peak level was significantly higher in short-stage protocols compared with the 3-min stepwise protocol, whereas HR and VO₂ showed no differences. Therefore, training zones based on PO determined in short-stage protocols might give an overestimation. Moreover, due to large random error in HR at VTs between the protocols, it is recommended that different protocols should not be used interchangeably within individuals.

Exercise training intensity determination in cardiovascular rehabilitation: Should the guidelines be reconsidered?

Aims

In the rehabilitation of cardiovascular disease patients a correct determination of the endurance-type exercise intensity is important to generate health benefits and preserve medical safety. It remains to be assessed whether the guideline-based exercise intensity domains are internally consistent and agree with physiological responses to exercise in cardiovascular disease patients.

Methods

A total of 272 cardiovascular disease patients without pacemaker executed a maximal cardiopulmonary exercise test on bike (peak respiratory gas exchange ratio >1.09), to assess peak heart rate (HRpeak), oxygen uptake (VO2peak) and cycling power output (Wpeak). The first and second ventilatory threshold (VT1 and VT2, respectively) was determined and extrapolated to %VO2peak, %HRpeak, %heart rate reserve (%HRR) and %Wpeak for comparison with guideline-based exercise intensity domains.

Results

VT1 was noted at 62 ± 10% VO2peak, 75 ± 10% HRpeak, 42 ± 14% HRR and 47 ± 11% Wpeak, corresponding to the high intensity exercise domain (for %VO2peak and %HRpeak) or low intensity exercise domain (for %Wpeak and %HRR). VT2 was noted at 84 ± 9% VO2peak, 88 ± 8% HRpeak, 74 ± 15% HRR and 76 ± 11% Wpeak, corresponding to the high intensity exercise domain (for %HRR and %Wpeak) or very hard exercise domain (for %HRpeak and %VO2peak). At best (when using %Wpeak) in only 63% and 72% of all patients VT1 and VT2, respectively, corresponded to the same guideline-based exercise intensity domain, but this dropped to about 48% and 52% at worst (when using %HRR and %HRpeak, respectively). In particular, the patient’s VO2peak related to differently elicited guideline-based exercise intensity domains ( P < 0.05).

Conclusion

The guideline-based exercise intensity domains for cardiovascular disease patients seem inconsistent, thus reiterating the need for adjustment.

Interobserver variability of ventilatory anaerobic threshold in asymptomatic volunteers

Background

The ventilatory anaerobic threshold (VO₂@AT) has been used in preoperative risk assessment and rehabilitation for many years. Our aim was to determine the interobserver variability of AT using cardiopulmonary exercise (CPET) data from a large epidemiological study (SHIP, Study of Health in Pomerania).

Methods

VO₂@AT was determined from CPET of 1,079 cross-sectional volunteers, according to American Heart Association guidelines. VO₂@AT determinations were compared between two experienced physicians, between physicians and qualified medical assistants, and between physicians or medical assistants and software-based algorithms. For the first 522 data sets, the two physicians discussed discrepant readings to reach consensus; the remaining data sets were analyzed without consensus discussion.

Results

VO₂@AT was detectable in 1,056 data sets. The physicians recorded identical VO₂@AT values in 319 out of 522 cases before consensus discussion (61.1%; intraclass correlation coefficient [ICC]: 0.90; 95% confidence interval [CI]: 0.88-0.92) and in 700 out of 1,056 cases overall (66.3%; ICC: 0.95; 95% CI: 0.95-0.96), with an interobserver difference of 0 ± 8% (95% limits of agreement [LOA]: ±161 mL/min). The interobserver difference was - 2 ± 18% (95% LOA: ±418 mL/min) between a physician and medical assistants, and - 19 ± 24% to - 22 ± 26% (95% LOAs: ±719-806 mL/min) between physicians or medical assistants and software-based algorithms.

Conclusions

Experienced physicians show high agreement when determining AT in asymptomatic volunteers. However, agreement between physicians and qualified medical assistants is lower, and there is substantial deviation in AT determination between physicians or medical assistants and software-based algorithms. This must be considered when using AT as a decision tool.

Pulmonary oxygen uptake on-kinetics can predict acute physiological responses to resistance exercise training in healthy young men

PURPOSE

To clarify whether pulmonary oxygen uptake kinetics ( τ V ˙ O 2 p ) at the onset of moderate-intensity exercise can predict acute physiological responses to resistance exercise training (RET).

METHODS

We investigated the relationship between τ V ˙ O 2 p and acute metabolic and hemodynamic responses to a single RET session in 27 healthy young adult men. Cardiopulmonary exercise was on a cycle ergometer, and a single RET at 30% or 60% of one-repetition maximum was on a bilateral leg-extension machine. We measured the anaerobic threshold, peak V ˙ O 2 and τ V ˙ O 2 p while cardiopulmonary exercising, and the rates of increase in blood lactate (Bla), heart rate (HR), systolic blood pressure (SBP) and rate pressure product (RPP) for a single RET.

RESULTS

There were significant positive associations between τ V ˙ O 2 p and the rates of increase in Bla, HR, SBP and RPP during a single RET session (P<0·05). However, the anaerobic threshold and peak V ˙ O 2 did not significantly affect these parameters.

CONCLUSION

The τ V ˙ O 2 p is a useful evaluation index for predicting acute physiological responses to RET.