Comparison of the Polar V800 and the Garmin Forerunner 230 to Predict V̇o2max

Peak oxygen consumption by smartwatches compared with cardiopulmonary exercise test in complex congenital heart disease

OBJECTIVE

To evaluate for correlation between exercise capacity as assessed by peak oxygen consumption (pVO2) measurement during a cardiopulmonary exercise test (CPET) and smartwatches reporting this parameter in patients with adult congenital heart disease (ACHD) complex lesions.

METHODS

A prospective study that included patients with ACHD either a Fontan circulation or a right ventricle supporting the systemic circulation who underwent two separate CPETs at least 1 year apart. Generalised estimating equations linear regression was performed to identify factors associated with correlation between smartwatch and CPET-derived pVO2.

RESULTS

48 patients (71% with a Fontan circulation, 42% females, mean age 33±9 years) underwent two CPETs between May 2018 and May 2022 with echocardiograms performed within 6 months of each CPET. Apple Watch was the predominant smartwatch used (79%). Smartwatch and CPET measured peak heart rate (Pearson correlation=0.932, 95% CI (0.899, 0.954)) and pVO2 (0.8627, 95% CI (0.8007, 0.9064) and 0.8634, 95% CI (0.7676, 0.9215) in the first and second CPET, respectively) correlated well, with smartwatch-measured pVO2 values measuring higher by a mean of 3.146 mL/kg/min (95% CI (2.559, 3.732)). Changes in pVO2 between the first and the second CPET also correlated well (Pearson correlation=0.9165, 95% CI (0.8549, 0.9525)), indicating that for every 1 mL/(min kg) change in CPET-measured pVO2, there was a corresponding 0.896 mL/(min kg) change in the smartwatch-measured pVO2.

CONCLUSION

Both absolute values and changes over time in pVO2 as measured by smartwatches and CPETs correlate well in patients with complex ACHD.

Validity and reliability of seismocardiography for the estimation of cardiorespiratory fitness

Background

Low cardiorespiratory fitness (ie, peak oxygen consumption [V . O2peak]) is associated with cardiovascular disease and all-cause mortality and is recognized as an important clinical tool in the assessment of patients. Cardiopulmonary exercise test (CPET) is the gold standard procedure for determination of V . O2peak but has methodological challenges as it is time-consuming and requires specialized equipment and trained professionals. Seismofit is a chest-mounted medical device for estimating V . O2peak at rest using seismocardiography.

Objective

The purpose of this study was to investigate the validity and reliability of Seismofit V . O2peak estimation in a healthy population.

Methods

On 3 separate days, 20 participants (10 women) underwent estimations of V . O2peak with Seismofit (×2) and Polar Fitness Test (PFT) in randomized order and performed a graded CPET on a cycle ergometer with continuous pulmonary gas exchange measurements.

Results

Seismofit V . O2peak showed a significant bias of -3.1 ± 2.4 mL·min-1·kg-1 (mean ± 95% confidence interval) and 95% limits of agreement (LoA) of ±10.8 mL·min-1·kg-1 compared to CPET. The mean absolute percentage error (MAPE) was 12.0%. Seismofit V . O2peak had a coefficient of variation of 4.5% ± 1.3% and an intraclass correlation coefficient of 0.95 between test days and a bias of 0.0 ± 0.4 mL·min-1·kg-1 with 95% LoA of ±1.6 mL·min-1·kg-1 in test-retest. In addition, Seismofit showed a 2.4 mL·min-1·kg-1 smaller difference in 95% LoA than PFT compared to CPET.

Conclusion

The Seismofit is highly reliable in its estimation of V . O2peak. However, based on the measurement error and MAPE >10%, the Seismofit V . O2peak estimation model needs further improvement to be considered for use in clinical settings.

Wearable activity trackers-advanced technology or advanced marketing?

Wearable devices represent one of the most popular trends in health and fitness. Rapid advances in wearable technology present a dizzying display of possible functions: from thermometers and barometers, magnetometers and accelerometers, to oximeters and calorimeters. Consumers and practitioners utilize wearable devices to track outcomes, such as energy expenditure, training load, step count, and heart rate. While some rely on these devices in tandem with more established tools, others lean on wearable technology for health-related outcomes, such as heart rhythm analysis, peripheral oxygen saturation, sleep quality, and caloric expenditure. Given the increasing popularity of wearable devices for both recreation and health initiatives, understanding the strengths and limitations of these technologies is increasingly relevant. Need exists for continued evaluation of the efficacy of wearable devices to accurately and reliably measure purported outcomes. The purposes of this review are (1) to assess the current state of wearable devices using recent research on validity and reliability, (2) to describe existing gaps between physiology and technology, and (3) to offer expert interpretation for the lay and professional audience on how best to approach wearable technology and employ it in the pursuit of health and fitness. Current literature demonstrates inconsistent validity and reliability for various metrics, with algorithms not publicly available or lacking high-quality validation studies. Advancements in wearable technology should consider standardizing validation metrics, providing transparency in used algorithms, and improving how technology can be tailored to individuals. Until then, it is prudent to exercise caution when interpreting metrics reported from consumer-wearable devices.

How do I track Cardiac Rehabilitation in my patient with ischemic heart disease using Strava

Abstract Cardiac rehabilitation is a program which reduces morbidity and mortality in patients with ischemic heart disease. However only some European centers provide these programs for patients diagnosed with cardiac ischemia. Therefore home-based programs were developed for cardiac rehabilitation. Strava is a social network developed to track activities of running and cycling both in athletes and individuals searching for recreation and sport activities. In our work we present an approach based on Strava tracking to improve the quality of cardiac rehabilitation. Real-time monitoring of heart rate, steps per minute and speed during recreational or competitive activities can be used to increase physical capacity in individuals with ischemic heart disease. Key words: cardiac rehabilitation, Strava, ischemic heart disease, home-based,