Publications
CamNtech Research Library
CamNtech products have been trusted by specialist researchers for over 25 years.
Our research library contains peer reviewed publications citing the use of our devices.
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Wearable Devices Suitable for Monitoring Twenty Four Hour Heart Rate Variability in Military Populations
Heart rate variability (HRV) measurements provide information on the autonomic nervous system and the balance between parasympathetic and sympathetic activity. A high HRV can be advantageous, reflecting the ability of the autonomic nervous system to adapt, whereas a low HRV can be indicative of fatigue, overtraining or health issues. There has been a surge in […]
Related Product: Actiheart
Publication Date: February 4, 2021
Assessment of energy expenditure during high intensity cycling and running using a heart rate and activity monitor in young active adults
Objective Although high intensity physical activities may represent a great proportion of the total energy expenditure in active people, only sparse studies have investigated the accuracy of wearable monitors to assess activity related energy expenditure (AEE) during high intensity exercises. Therefore, the purpose of the present study was to investigate the accuracy of the Actiheart, […]
Related Product: Actiheart
Publication Date: November 7, 2019
Validity of the Actiheart step test for the estimation of maximum oxygen consumption in endurance athletes and healthy controls.
Submaximal step tests are often used for estimation of maximum oxygen consumption (VO2max) in humans. The validity of the Actiheart step test for VO2 max estimation was not fully studied yet. Therefore, purpose of the study was to estimate VO2 max using the Actiheart step test and to compare the data with measured VO2 max […]
Related Product: Actiheart
Publication Date: March 12, 2019
Harmonisation of Physical Activity Variables by Indirect Validation: A Doubly Labelled Water Study
Harmonisation of data for pooled analysis relies on the principle of inferential equivalence between variables from different sources. Ideally, this is achieved using models of the direct relationship with gold standard criterion measures, but the necessary validation data are often unavailable. This study examines an alternative method of harmonisation by indirect validation. Starting methods were […]
Related Product: Actiheart
Publication Date: January 4, 2019
How well do activity monitors estimate energy expenditure? A systematic review and meta-analysis of the validity of current technologies
Objective To determine the accuracy of wrist and arm-worn activity monitors’ estimates of energy expenditure (EE). Data sources SportDISCUS (EBSCOHost), PubMed, MEDLINE (Ovid), PsycINFO (EBSCOHost), Embase (Ovid) and CINAHL (EBSCOHost). Design A random effects meta-analysis was performed to evaluate the difference in EE estimates between activity monitors and criterion measurements. Moderator analyses were conducted to […]
Related Product: Actiheart
Publication Date: September 7, 2018
Level of agreement between physical activity levels measured by ActiHeart and the International Physical Activity Questionnaire in persons with intellectual disability
Purpose: The purpose of this study was to determine the level of agreement between objective physical activity (PA) (ActiHeart®) and subjective proxy-respondent International Physical Activity Questionnaire-short version (IPAQ-S) data in adults with intellectual disabilities (IDs). Method: Fifty-eight participants wore ActiHeart® monitors for seven consecutive days. Caregivers of each participant completed the IPAQ-S on behalf of […]
Related Product: Actiheart
Publication Date: January 1, 2018
An original piecewise model for computing energy expenditure from accelerometer and heart rate signals
Objective: Activity energy expenditure (EE) plays an important role in healthcare, therefore, accurate EE measures are required. Currently available reference EE acquisition methods, such as doubly labeled water and indirect calorimetry, are complex, expensive, uncomfortable, and/or difficult to apply on real time. To overcome these drawbacks, the goal of this paper is to propose a […]
Related Product: Actiheart
Publication Date: July 28, 2017
Perceived and objectively measured physical activity in high school students: is there any link between aerobic fitness, psychological responses and acute exercise?
Background and aim The purpose of this study was to compare the amount of physical activity and sedentary time from the self-administered, long version of the IPAQ with an objective measure of them using an accelerometer in a high school student’s sample. The present study also examined whether the amount of physical activity and sedentary […]
Related Product: Actiheart
Publication Date: April 1, 2017
Assessment of laboratory and daily energy expenditure estimates from consumer multi-sensor physical activity monitors
Wearable physical activity monitors are growing in popularity and provide the opportunity for large numbers of the public to self-monitor physical activity behaviours. The latest generation of these devices feature multiple sensors, ostensibly similar or even superior to advanced research instruments. However, little is known about the accuracy of their energy expenditure estimates. Here, we […]
Related Product: Actiheart
Publication Date: February 24, 2017
Validation of total daily energy expenditure calculated with Actiheart against doubly labeled water method in Costa Rican schoolchildren
The purpose of this study was to use the measurement of the PAEE taken from Actiheart in order to calculate the TEE in Costa Rican schoolchildren, and at the same time, to determine the effectiveness when it is compared against the TEE obtained by the DLW. A total of sixteen male schoolchildren were measured for […]
Related Product: Actiheart
Publication Date: October 8, 2015
Estimation of free-living energy expenditure by heart rate and movement sensing: a doubly-labelled water study
Background Accurate assessment of energy expenditure (EE) is important for the study of energy balance and metabolic disorders. Combined heart rate (HR) and acceleration (ACC) sensing may increase precision of physical activity EE (PAEE) which is the most variable component of total EE (TEE). Objective To evaluate estimates of EE using ACC and HR data […]
Related Product: Actiheart
Publication Date: September 8, 2015
Comparison of total energy expenditure assessed by two devices in controlled and free-living conditions
The objective of this study was to evaluate the validity of total energy expenditure (TEE) provided by Actiheart® and Armband®. Normal-weight adult volunteers wore both devices either for 17 hours in a calorimetric chamber (CC, n = 49) or for 10 days in free-living conditions (FLC) outside the laboratory (n = 41). The two devices […]
Related Product: Actiheart
Publication Date: January 1, 2015
Accuracy of a combined heart rate and motion sensor for assessing energy expenditure in free-living adults during a double-blind crossover caffeine trial using doubly labeled water as the reference method
Background/Objectives: A combined heart rate (HR) and motion sensor (Actiheart) has been proposed as an accurate method for assessing total energy expenditure (TEE) and physical activity energy expenditure (PAEE). However, the extent to which factors such as caffeine may affect the accuracy by which the estimated HR-related PAEE contribution will affect TEE and PAEE estimates […]
Related Product: Actiheart
Publication Date: January 1, 2015
Reliability and validity of the Questionnaire on Annual Physical Activity Pattern: A validation study using combined heart rate and accelerometry data as an objective measurement
Introduction Physical activity (PA) is a modifiable lifestyle factor with great public health potential. However, it is still unclear which type, intensity, and temporal pattern of PA is most beneficial. Therefore, a Questionnaire on Annual Physical Activity Pattern (QUAP) for healthy adults was developed; focusing on a detailed assessment of past year PA.The aim was […]
Related Product: Actiheart
Publication Date: December 31, 2014
Validity of electronically administered Recent Physical Activity Questionnaire (RPAQ) in ten European countries
Objective To examine the validity of the Recent Physical Activity Questionnaire (RPAQ) which assesses physical activity (PA) in 4 domains (leisure, work, commuting, home) during past month. Methods 580 men and 1343 women from 10 European countries attended 2 visits at which PA energy expenditure (PAEE), time at moderate-to-vigorous PA (MVPA) and sedentary time were […]
Related Product: Actiheart
Publication Date: March 25, 2014
Evaluation of Actiheart and a 7 d activity diary for estimating free-living total and activity energy expenditure using criterion methods in 1· 5-and 3-year-old children
Accurate and easy-to-use methods to assess free-living energy expenditure in response to physical activity in young children are scarce. In the present study, we evaluated the capacity of (1) 4 d recordings obtained using the Actiheart (mean heart rate (mHR) and mean activity counts (mAC)) to provide assessments of total energy expenditure (TEE) and activity […]
Related Product: Actiheart
Publication Date: February 6, 2014
Validation of SenseWear Armband and ActiHeart monitors for assessments of daily energy expenditure in free‐living women with chronic obstructive pulmonary disease
To provide individually adapted nutritional support to patients with chronic obstructive pulmonary disease (COPD), objective and reliable methods must be used to assess patient energy requirements. The aim of this study was to validate the use of SenseWear Armband (SWA) and ActiHeart (AH) monitors for assessing total daily energy expenditure (TEE) and activity energy expenditure […]
Related Product: Actiheart
Publication Date: November 26, 2013
Evaluations of Actiheart, IDEEA® and RT3 monitors for estimating activity energy expenditure in free-living women
Activity energy expenditure (AEE) during free-living conditions can be assessed using devices based on different principles. To make proper comparisons of different devices’ capacities to assess AEE, they should be evaluated in the same population. Thus, in the present study we evaluated, in the same group of subjects, the ability of three devices to assess […]
Related Product: Actiheart
Publication Date: September 6, 2013
Measuring activity energy expenditure: accuracy of the GT3X+ and Actiheart monitors
The purpose was to determine the accuracy of the GT3X+ and Actiheart monitors for estimating energy expenditure (EE) and steps. Additionally, to investigate agreement between waist- and wrist-mounted GT3X+ EE outputs. Nineteen participants (mean age=30) completed three treadmill walking trials at self-selected slow, medium, and fast speeds while wearing two GT3X+ (waist and wrist) and […]
Related Product: Actiheart
Publication Date: July 16, 2013
Estimation of Physical Activity Energy Expenditure in Children during Stimulated Free-living Activities: Precision of the ActiHeart Sensor
The validity of the Actiheart – a combined heart rate and movement sensor – for assessing physical activity energy expenditure has been demonstrated in older children during treadmill walking and running and in a limited range of ‘lifestyle’ physical activities (Corder et al., 2005, 2007). Our aim was to evaluate the precision of the Actiheart […]
Related Product: Actiheart
Publication Date: June 26, 2013
Validation of the Actical and Actiheart monitor in ambulatory children with Spina Bifida
Background Ambulatory children with Spina Bifida (SB) often show a decline in physical activity leading to deconditioning and functional decline. Therefore, assessment and promotion of physical activity is important. Because energy expenditure during activities is higher in these children, the use of existing pediatric equations to predict physical activity energy expenditure (PAEE) may not be […]
Related Product: Actiheart
Publication Date: April 15, 2013
Validity of combining heart rate and uniaxial acceleration to measure free-living physical activity energy expenditure in young men
Combining accelerometry (ACC) with heart rate (HR) monitoring is thought to improve activity energy expenditure (AEE) estimations compared with ACC alone to evaluate the validity of ACC and HR used alone or combined. The purpose of this study was to estimate AEE in free-living conditions compared with doubly labeled water (DLW). Ten-day free-living AEE was […]
Related Product: Actiheart
Publication Date: December 1, 2012
Actiheart based estimates of body expenditure are accurate during treadmill walking, arm ergometry and bicycle ergometry
The Actiheart system (CamNtech Neurotechnology Ltd, Cambridge UK) is a small portable device that collects ECG derived heart rate and 3-dimensional accelerometer data, and uses these data to estimate body energy expenditure (BEE). High levels of accuracy for Actiheart based estimates of BEE have been reported over a range of daily activities. However, with the […]
Related Product: Actiheart
Publication Date: December 1, 2012
Validation of uniaxial and triaxial accelerometers for the assessment of physical activity in preschool children
Purpose: Given the unique physical activity (PA) patterns of preschoolers, wearable electronic devices for quantitative assessment of physical activity require validation in this population. Study objective was to validate uniaxial and triaxial accelerometers in preschoolers. Methods: Room calorimetry was performed over 3 hours in 64 preschoolers, wearing Actical, Actiheart, and RT3 accelerometers during play, slow, […]
Related Product: Actiheart
Publication Date: September 1, 2012
Validation of the Actiheart for estimating physical activity related energy expenditure in pregnancy
Background & aims The objective of this study was to assess the validity of the individually calibrated Actiheart (a combined heart rate and movement sensor device), in pregnant women against indirect calorimetry in a laboratory setting. Methods Ten healthy pregnant women (aged 32.9 ± 3.2 yrs, pre-pregnancy BMI = 21.0 ± 2.4 kg/m2, 36.9 ± […]
Related Product: Actiheart
Publication Date: February 14, 2012
Criterion validity of a 10-category scale for ranking physical activity in Norwegian women
Background Accurate measurement of physical activity (PA) is critical to establish dose-response relationships with various health outcomes. We compared the self-administered PA questionnaire from the Norwegian Women and Cancer Study (NOWAC) with a criterion method in middle-aged Norwegian women. Methods A sample of 177 randomly recruited healthy women attended two clinical visits approximately 4-6 months […]
Related Product: Actiheart
Publication Date: January 19, 2012
Validity of a short questionnaire to assess physical activity in 10 European countries
To accurately examine associations of physical activity (PA) with disease outcomes, a valid method of assessing free-living activity is required. We examined the validity of a brief PA questionnaire (PAQ) used in the European Prospective Investigation into Cancer and Nutrition (EPIC). PA energy expenditure (PAEE) and time spent in moderate and vigorous physical activity (MVPA) […]
Related Product: Actiheart
Publication Date: January 1, 2012
Evaluation of two portable sensors for energy expenditure assessment during high-intensity running
The correct assessment of individual energy requirements of athletes remains a challenge. Available literature indicates that accelerometry-based sensors underestimated energy expenditure in athletes, especially during high-intensity exercise. The goal of our study was to evaluate two commercially available devices (Actiheart; SenseWear Pro3) during high-intensity running and to identify potential sources of error. Twenty-nine male endurance- […]
Related Product: Actiheart
Publication Date: November 17, 2011
Total Energy Expenditure: Combined Heart Rate and Motion Sensor vs Uni-Axial Accelerometry Models
Objective. To compare total daily energy expenditure (TDEE) from accelerometry models and combined heart rate with motion sensor. Methods. Twenty male subjects were involved in this study (25.5 5.3 years; 73.2 9.9 kg). TDEE was measured using a combined heart rate (HR) monitor with a motion sensor (Actiheart), and the corresponding equations for the Actigraph […]
Related Product: Actiheart
Publication Date: November 2, 2011
Comparison of two systems for long-term heart rate variability monitoring in free-living conditions-a pilot study
Objective A number of small portable systems that can measure HRV are available to address questions related to autonomic regulation in free-living subjects. However, ambulatory HRV measurements obtained through use of these systems have not previously been validated against standard clinical measurements such as Holter recordings. The objective of this study was to validate HRV […]
Related Product: Actiheart
Publication Date: April 12, 2011
A comparison of energy expenditure estimates from the Actiheart and Actical physical activity monitors during low intensity activities, walking, and jogging
Combining accelerometry with heart rate monitoring has been suggested to improve energy estimates, however, it remains unclear whether the single, currently existing commercially available device combining these data streams (Actiheart) provides improved energy estimates compared to simpler and less expensive accelerometry-only devices. The purpose of this study was to compare the validity of the heart […]
Related Product: Actiheart
Publication Date: April 1, 2011
Accuracy and validity of a combined heart rate and motion sensor for the measurement of free-living physical activity energy expenditure in adults in Cameroon
Background The increasing burden of non-communicable diseases in sub-Saharan Africa (SSA) warrants rigorous studies of contributing lifestyle factors. Combined heart rate (HR) and movement monitoring make it possible to objectively measure physical activity in free-living individuals. We examined the validity of a combined HR and motion sensor in estimating physical activity energy expenditure (PAEE) in […]
Related Product: Actiheart
Publication Date: February 1, 2011
Monitoring intensity during head-out water based activities (water fitness): a comparison among different measurement techniques
The aim of this study was to compare different measurement techniques (indirect calorimetry, IC; heart rate monitoring, HR; Actiheart, AH, an activity monitoring system; rates of perceived exertion, RPE) to estimate physical activity intensity (PAI) during water based exercises (WE). Twelve young active women performed five different WE at three different movement frequencies (15 trials) […]
Related Product: Actiheart
Publication Date: October 2, 2010
Review of prediction models to estimate activity-related energy expenditure in children and adolescents
Purpose. To critically review the validity of accelerometry-based prediction models to estimate activity energy expenditure (AEE) in children and adolescents. Methods. The CINAHL, EMBASE, PsycINFO, and PubMed/MEDLINE databases were searched. Inclusion criteria were development or validation of an accelerometer-based prediction model for the estimation of AEE in healthy children or adolescents (6–18 years), criterion measure: […]
Related Product: Actiheart
Publication Date: June 29, 2010
Validation of cross-sectional time series and multivariate adaptive regression splines models for the prediction of energy expenditure in children and adolescents using doubly labeled water
Accurate, nonintrusive, and inexpensive techniques are needed to measure energy expenditure (EE) in free-living populations. Our primary aim in this study was to validate cross-sectional time series (CSTS) and multivariate adaptive regression splines (MARS) models based on observable participant characteristics, heart rate (HR), and accelerometer counts (AC) for prediction of minute-by-minute EE, and hence 24-h […]
Related Product: Actiheart
Publication Date: June 23, 2010
Multivariate adaptive regression splines models for the prediction of energy expenditure in children and adolescents
Advanced mathematical models have the potential to capture the complex metabolic and physiological processes that result in heat production or energy expenditure (EE). Multivariate adaptive regression splines (MARS) is a nonparametric method that estimates complex nonlinear relationships by a series of spline functions of the independent predictors. The specific aim of this study is to […]
Related Product: Actiheart
Publication Date: January 1, 2010
Daily physical activity levels as measured by self-report and accelerometry in patients with heart failure
Introduction: Assessment of physical activity is an important outcome requiring valid and reliable measures for physical activity (PA) research in patients with heart failure (HF). Purpose: The purpose of this study was to assess reliability of two accelerometer measures of PA using Intraclass Correlation Coefficients (ICCs) and to compare PA levels from self-report and physiological […]
Related Product: Actiheart
Publication Date: August 1, 2009
The Actiheart accelerometer as a method to record energy expenditure of preschool children
In the past three decades, the number of overweight children aged 6-12 years has tripled and the number of overweight adolescents aged 12-19 years has doubled. The underlying reason for the obesity epidemic is complex, but reduced physical activity is likely a major contributor. Therefore, while quantifying energy expenditure is important, relatively little research has […]
Related Product: Actiheart
Publication Date: May 1, 2009
Validation of the Actiheart monitor for the measurement of physical activity
The Actiheart monitor uniquely allows simultaneous measurement of heart rate and movement counts. The purpose of this study was to establish validity evidence for the Actiheart monitor under laboratory and free-living conditions. A total of 34 college students (17 males and 17 females, age = 21.8 ± 3.6 years) participated in the study. In the […]
Related Product: Actiheart
Publication Date: January 15, 2009
Reliability of physical activity and heart rate measures in children during steady rate and intermittent treadmill exercise: The A-CLASS project
To help clarify the dose-response relationship between physical activity (PA) and health outcomes, a PA measurement tool must be valid and demonstrate adequate reliability (Wareham and Rennie, 1998). To date only one reported study has assessed the test-retest reliability of field-based PA monitors with participants (Rowlands et al., 2007). In trained runners undergoing identical treadmill […]
Related Product: Actiheart
Publication Date: June 1, 2008
Hierarchy of individual calibration levels for heart rate and accelerometry to measure physical activity
Combining accelerometry with heart rate (HR) monitoring may improve precision of physical activity measurement. Considerable variation exists in the relationships between physical activity intensity (PAI) and HR and accelerometry, which may be reduced by individual calibration. However, individual calibration limits feasibility of these techniques in population studies, and less burdensome, yet valid, methods of calibration […]
Related Product: Actiheart
Publication Date: August 1, 2007
Comparison of activity monitors accuracy to estimate energy expenditure of daily living activities
Accurate assessment of the total amount of physical activity (PA) or the energy expenditure (EE) in free living condition is a big challenge. A priority has been placed on the study of valid and reliable measures for all levels of PA. New technologies are available for objectively measuring PA and inferring EE: the Actiheart -AH-(Cambridge […]
Related Product: Actiheart
Publication Date: June 28, 2007
Accuracy of the Actiheart for the assessment of energy expenditure in adults.
Background/Objective: The Actiheart (Mini Mitter, Sunriver, OR, USA) uses heart rate (HR) and activity data to predict activity energy expenditure (AEE). Currently, the Actiheart has only been tested during laboratory conditions. Therefore, the objective of this study was to validate the Actiheart prediction method against indirect calorimetry during a wide range of activities in a […]
Related Product: Actiheart
Publication Date: April 18, 2007
Assessment of low-to-moderate intensity physical activity thermogenesis in young adults using synchronized heart rate and accelerometry with branched-equation modeling
Low-to-moderate intensity physical activity thermogenesis is a highly variable and quantitatively important component of total energy expenditure that is difficult to assess outside the laboratory. Greater precision and accuracy in the measurement of this key contributor to energy balance is a research priority. We developed a laboratory-based protocol that simulated a range of low-to-moderate intensity […]
Related Product: Actiheart
Publication Date: April 1, 2006
Integration of physiological and accelerometer data to improve physical activity assessment
PURPOSE:Accurate measurement of physical activity (PA) is a prerequisite to determine dose-response relationships between activity and health. The combination of HR and accelerometers (ACC) holds promise for improving the accuracy of PA assessment, but it is unclear how currently proposed modeling techniques compare and to what extent different levels of individual calibration (IC) of HR […]
Related Product: Actiheart
Publication Date: November 1, 2005
Comparison of PAEE from combined and separate heart rate and movement models in children
PURPOSE:Accurate measurement of physical activity in children is a challenge. Combining physiological (e.g., heart rate (HR)) and body movement registration (e.g., accelerometry) may overcome limitations with either method used alone. This study aimed to compare the estimated physical activity energy expenditure (PAEE) from hip- and ankle-mounted MTI Actigraphs, a hip-mounted Actical, and a new combined […]
Related Product: Actiheart
Publication Date: October 1, 2005
Measurement of energy expenditure during laboratory and field activities
This dissertation was designed to examine the validity of heart rate (HR) and motion sensors for estimating energy expenditure (EE) during activities ranging from sedentary behaviors to vigorous exercise. A secondary purpose was to devise new ways to improve on current methods of estimating EE. Specific aims of the dissertation were: (1) to examine the […]
Related Product: Actiheart
Publication Date: August 1, 2005
Reliability and validity of the combined heart rate and movement sensor Actiheart
Accurate quantification of physical activity energy expenditure is a key part of the effort to understand disorders of energy metabolism. The Actiheart, a combined heart rate (HR) and movement sensor, is designed to assess physical activity in populations. Objective: To examine aspects of Actiheart reliability and validity in mechanical settings and during walking and running. […]
Related Product: Actiheart
Publication Date: February 16, 2005
Branched equation modeling of simultaneous accelerometry and heart rate monitoring improves estimate of directly measured physical activity energy expenditure
The combination of heart rate (HR) monitoring and movement registration may improve measurement precision of physical activity energy expenditure (PAEE). Previous attempts have used either regression methods, which do not take full advantage of synchronized data, or have not used movement data quantitatively. The objective of the study was to assess the precision of branched […]
Related Product: Actiheart
Publication Date: January 1, 2004
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