Physical activity, cardiorespiratory fitness, and cardiovascular health: A clinical practice statement of the American Society for Preventive Cardiology Part II: Physical activity, cardiorespiratory fitness, minimum and goal intensities for exercise training, prescriptive methods, and special patient populations

Exploring the effects of real-time online cardiac telerehabilitation using wearable devices compared to gym-based cardiac exercise in people with a recent myocardial infarction: a randomised controlled trial

Background

Exercise-based cardiac rehabilitation (CR) is a non-pharmacological multidisciplinary programme for individuals after myocardial infarction (MI) that offers multiple health benefits. One of the greatest barriers to CR participation is the travel distance to the rehabilitation centre. Remotely monitored CR appears to be at least as effective in improving cardiovascular risk factors and exercise capacity as traditional centre-based CR. Nevertheless, the efficacy of remotely monitored CR in individuals with a recent MI has yet to be examined.

Methods

A total of 30 individuals (8 women, 22 men) after a recent (i.e., <4 weeks) MI were randomly allocated into two groups (online home-based and gym-based groups). Both groups underwent a 26-week CR programme three times per week. All patients performed baseline and 24-week follow-up measurements where peak oxygen uptake (VO2peak), mean daily steps, distance, and calories were assessed.

Results

The online group showed an improvement in mean daily steps (p < 0.05) and mean daily distance (p < 0.05) at 24 weeks compared to the gym-based group. The paired-sample t-test showed that all the assessed variables were statistically (p < 0.001) improved for both groups at 24 weeks. Pearson's r demonstrated positive correlations between VO2peak and mean daily distance (r = 0.375), and negative correlations between VO2peak and muscle (r = -0.523) and fat masses (r = -0.460). There were no exercise-induced adverse events during the study.

Conclusion

Our findings might indicate that a real-time online supervised CR exercise programme using wearable technology to monitor the haemodynamic responses in post-MI patients is equally effective as a gym-based exercise programme.

Lifestyle Intervention for the Prevention of Cardiovascular Disease

Lifestyle medicine is a cornerstone of cardiovascular disease prevention and early disease intervention. A leading cause of death in developed countries, modifiable risk factors of cardiovascular disease like diet, exercise, substance use, and sleep hygiene have significant impacts on population morbidity and mortality. One should address these amendable risks in all patients, independently, and stress the importance of intervention adherence while avoiding the sacrifice of patient trust. One must also understand a patient's psychological well-being can be compromised by organic chronic disease states, and poor psychological well-being can have a negative impact on patient compliance and overall health.

Joint associations of device-measured physical activity and abdominal obesity with incident cardiovascular disease: a prospective cohort study

OBJECTIVE

To examine the joint associations between physical activity and abdominal obesity with the risk of cardiovascular disease (CVD) events.

METHODS

We included 70 830 UK Biobank participants (mean age±SD=61.6 ± 7.9 years; 56.4% women) with physical activity measured by wrist-worn accelerometers and without major chronic diseases. Participants were jointly categorised into six groups based on their physical activity level (tertiles of total volume and specific intensity levels) and presence or absence of abdominal obesity based on measured waist circumference. Associations with incident CVD (fatal and non-fatal events) were determined using proportional subdistribution hazard models with multivariable adjustment.

RESULTS

After excluding events during the first 2 years of follow-up, participants were followed for a median of 6.8 years, during which 2795 CVD events were recorded. Compared with the low abdominal adiposity and highest tertile of physical activity, abdominal obesity was associated with higher risk of incident CVD, especially in those with low levels of vigorous-intensity physical activity (HR 1.42, 95% CI 1.22 to 1.64). Approximately 500 min per week of moderate-to-vigorous intensity and approximately 30-35 min of vigorous-intensity physical activity offset the association of abdominal obesity and the risk of having a CVD event.

CONCLUSION

Physical activity equivalent to approximately 30-35 min of vigorous intensity per week appears to offset the association between abdominal obesity and incident CVD. About 15 times more physical activity of at least moderate intensity is needed to achieve similar results.

Full Familiarisation Is Not Required for the Self-Paced 1 km Treadmill Walk to Predict Peak Oxygen Uptake in Phase IV Cardiac Patients

Exercise is a recommended part of phase IV cardiovascular rehabilitation (CR). The 1 km treadmill walk test (1-KTWT) is a submaximal continuous exercise test to predict cardiorespiratory fitness in patients with cardiovascular disease. We examined physiological, metabolic and subjective responses in patients with cardiovascular disease with self-selected, unchanging walking speed for two 1-KTWTs. Fifteen men (age: 65 ± 9 yr, height: 174 ± 5 cm, body mass: 86 ± 17 kg, BMI: 28.5 ± 5.5 kg·m-2, body fat%: 27.7 ± 7.5%, 10 on beta-blockers) were recruited from phase IV CR groups in the United Kingdom. Participants established a self-selected walking speed for the 1-KTWT and performed the 1-KTWT on separate days with recording of physiological responses to predict V˙O2peak with equations. For the two 1-KTWTs, no differences existed for walking speed, mean and maximal heart rates, oxygen uptake, predicted V˙O2peak (1st 1-KTWT (range: 41-78% V˙O2peak, 95%CI, 53-65; 2nd 1-KTWT range: 43-78% V˙O2peak, 95%CI, 52-65) and rating of perceived exertion. In phase IV cardiac patients, the 1-KTWT with self-selected, unchanging walking speed can be used for V˙O2peak prediction without the need for a full familiarisation. The self-selected constant walking speed for the first 1-KTWT can be used to support nonsupervised physical activity for phase IV CR patients.

Facilitators and barriers of initiation and maintenance of physical activity among people with coronary heart disease: a qualitative study

PURPOSE

We aimed to describe the facilitators and barriers of physical activity for patients with coronary heart disease.

METHODS

A qualitative descriptive study using semi-structured interviews was conducted with 15 participants with coronary heart disease. The interview guide was developed based on a multi-theory model. Interviews were audio-recorded, transcribed verbatim, and analyzed using a thematic analysis.

RESULTS

Two main themes were identified: facilitators of initiation and maintenance of physical activity (behavioral motivation, perceived benefits, behavioral confidence, supportive physical environment, positive emotional experience, self-regulation, supportive social environment, illness perception, and excellent self-control), barriers of initiation and maintenance of physical activity (perceived barriers, restricted physical environment, psychological distress, insufficient social support, and poor self-control).

CONCLUSIONS

This study presents an in-depth theory-based exploration of facilitators and barriers to initiating and maintaining physical activity among people with coronary heart disease. Relevant factors should be taken into account to increase their effectiveness when designing the target interventions to encourage a physically active lifestyle in this population.

Aquatic high-intensity interval training (HIIT) may be similarly effective to land-based HIIT in improving exercise capacity in people with chronic conditions: a systematic review and meta-analysis

Objective

To investigate the effect of aquatic high-intensity interval training (AHIIT) on exercise capacity in people with chronic conditions.

Design

Systematic review and meta-analysis.

Participants

Adults (age ≥18 years) with any chronic conditions (long duration, continuing health problems).

Data sources

The databases Medline, EMBASE, CINAHL, SPORTSDiscus, PEDro and The Cochrane Library were searched from inception to 11 August 2023.

Eligibility criteria

Randomised or non-randomised controlled trials of adults reporting one or more chronic conditions were included, comparing the effect of AHIIT with a non-exercising control group, land-based high-intensity interval training (LBHIIT) or aquatic moderate-intensity continuous training (AMICT).

Results

Eighteen trials with 868 participants with chronic musculoskeletal, respiratory, cardiovascular, metabolic or neurological conditions were included. Adherence to AHIIT was high, ranging from 84% to 100%. There was moderate certainty in evidence according to the Grading of Recommendations Assessment, Development and Evaluation system for a moderate beneficial effect on exercise capacity standardised mean differences (SMD) 0.78 (95% CI 0.48 to 1.08), p<0.00001) of AHIIT compared with a non-exercising control group. There was moderate certainty in evidence for no difference of effects on exercise capacity (SMD 0.28 (95% CI -0.04 to 0.60), p=0.08) of AHIIT compared with LBHIIT. There was moderate certainty in evidence for small effect on exercise capacity (SMD 0.45 (95% CI 0.10 to 0.80), p=0.01) of AHIIT compared with AMICT.

Conclusion

There are beneficial effects of AHIIT on exercise capacity in people with a range of chronic conditions. AHIIT has similar effects on exercise capacity as LBHIIT and may represent an alternative for people unable to perform LBHIIT.

PROSPERO registration number

CRD42022289001.

A Machine Learning Approach to Developing an Accurate Prediction of Maximal Heart Rate During Exercise Testing in Apparently Healthy Adults

PURPOSE

Maximal heart rate (HR max ) continues to be an important measure of adequate effort during an exercise test. The aim of this study was to improve the accuracy of HR max prediction using a machine learning (ML) approach.

METHODS

We used a sample from the Fitness Registry of the Importance of Exercise National Database, which included 17 325 apparently healthy individuals (81% males) who performed a maximal cardiopulmonary exercise test. Two standard formulas for HR max prediction were tested: Formula1 = 220 - age (yr), root-mean-squared error (RMSE) 21.9, relative root-mean-squared error (RRMSE) 1.1; and Formula2 = 209.3 - 0.72 × age (yr), RMSE 22.7 and RRMSE 1.1. For ML model prediction, we used age, weight, height, resting HR, and systolic and diastolic blood pressure. The following ML algorithms to predict HR max were applied: lasso regression (LR), neural networks (NN), support vector machine (SVM) and random forests (RF). An evaluation was performed using cross-validation and by computing the RMSE and RRMSE, Pearson correlation, and Bland-Altman plots. The best predictive model was explained with Shapley Additive Explanations (SHAP).

RESULTS

The HR max for the cohort was 162 ± 20 bpm. All ML models improved HR max prediction and reduced RMSE and RRMSE compared with Formula1 (LR: 20.2%, NN: 20.4%, SVM: 22.2%, and RF: 24.7%). The predictions of all algorithms significantly correlated with HR max ( r = 0.49, 0.51, 0.54, 0.57, respectively; P < .001). Bland-Altman analysis demonstrated lower bias and 95% CI for all ML models in comparison with standard equations. The SHAP explanation showed a high impact of all selected variables.

CONCLUSIONS

Machine learning, particularly the RF model, improved prediction of HR max using readily available measures. This approach should be considered for clinical application to refine HR max prediction.

Quantifying the benefits of inefficient walking: Monty Python inspired laboratory based experimental study

OBJECTIVE

To compare the rate of energy expenditure of low efficiency walking with high efficiency walking.

DESIGN

Laboratory based experimental study.

SETTING

United States.

PARTICIPANTS

13 healthy adults (six women, seven men) with no known gait disorder, mean (±standard deviation) age 34.2±16.1 years, height 174.2±12.6 cm, weight 78.2±22.5 kg, and body mass index 25.6±6.0.

INTERVENTION

Participants performed three, five minute walking trials around an indoor 30 m course. The first trial consisted of walking at a freely chosen walking speed in the participant's usual style. The next two trials consisted of low efficiency walks in which participants were asked to duplicate the walks of Mr Teabag and Mr Putey (acted by John Cleese and Michael Palin, respectively) in the legendary Monty Python Ministry of Silly Walks (MoSW) skit that first aired in 1970. Distance covered during the five minute walks was used to calculate average speed. Ventilation and gas exchange were collected throughout to determine oxygen uptake (V̇O₂; mL O₂/kg/min) and energy expenditure (EE; kcal/kg/min; 1 kcal=4.18 kJ), reported as mean±standard deviation.

MAIN OUTCOME MEASURES

V̇O₂ and EE.

RESULTS

V̇O₂ and EE were about 2.5 times higher (P<0.001) during the Teabag walk compared with participants' usual walk (27.9±4.8 v 11.3±1.9 mL O₂/kg/min; 0.14±0.03 v 0.06±0.01 kcal/kg/min), but were not different during the Putey walk (12.3±1.8 mL/kg/min; 0.06±0.01 kcal/kg/min). Each minute of Teabag walking increased EE over participants' usual walking by an average of 8.0 kcal (range 5.5-12.0) in men and by 5.2 kcal (range 3.9-6.2) in women, and qualified as vigorous intensity physical activity (>6 resting metabolic equivalents).

CONCLUSIONS

For adults with no known gait disorder who average approximately 5000 steps/day, exchanging about 22%-34% of their daily steps with higher energy, low efficiency walking in Teabag style-requiring around 12-19 min-could increase daily EE by 100 kcal. Adults could achieve 75 minutes of vigorous intensity physical activity per week by walking inefficiently for about 11 min/day. Had an initiative to promote inefficient movement been adopted in the early 1970s, we might now be living among a healthier society. Efforts to promote higher energy-and perhaps more joyful-walking should ensure inclusivity and inefficiency for all.