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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Benefits of a Paleolithic diet with and without supervised exercise on fat mass, insulin sensitivity, and glycemic control: a randomized controlled trial in individuals with type 2 diabetes
Background Means to reduce future risk for cardiovascular disease in subjects with type 2 diabetes are urgently needed. Methods Thirty‐two patients with type 2 diabetes (age 59 ± 8 years) followed a Paleolithic diet for 12 weeks. Participants were randomized to either standard care exercise recommendations (PD) or 1‐h supervised exercise sessions (aerobic exercise and resistance training) […]
Related Product: Actiheart
Publication Date: January 1, 2017
Estimation of physical activity energy expenditure during free-living from wrist accelerometry in UK adults
Background Wrist-worn accelerometers are emerging as the most common instrument for measuring physical activity in large-scale epidemiological studies, though little is known about the relationship between wrist acceleration and physical activity energy expenditure (PAEE). Methods 1695 UK adults wore two devices simultaneously for six days; a combined sensor and a wrist accelerometer. The combined sensor […]
Related Product: Actiheart
Publication Date: December 19, 2016
Investigating the physiological and psychosocial responses of single-and dual-player exergaming in young adults
Objective: This study investigated the effect of acute exergaming on the physiological and psychosocial responses of young adults and the modulatory effect of a single- or dual-player game play situation. Materials and Methods: Thirty-six participants (19 male; 21.7 ± 3.8 years; 23.65 ± 3.17 kg/m2) each completed two 30-minute exergame sessions in a randomized order (single and dual player) while […]
Related Product: Actiheart
Publication Date: December 1, 2016
Energy expenditure in frontotemporal dementia: a behavioural and imaging study
Abnormal eating behaviour and metabolic parameters including insulin resistance, dyslipidaemia and body mass index are increasingly recognized as important components of neurodegenerative disease and may contribute to survival. It has previously been established that behavioural variant frontotemporal dementia is associated with abnormal eating behaviour characterized by increased sweet preference. In this study, it was hypothesized […]
Related Product: Actiheart
Publication Date: October 27, 2016
Low-power metabolic equivalents estimation algorithm using adaptive acceleration sampling.
This paper describes a proposed low-power metabolic equivalent estimation algorithm that can calculate the value of metabolic equivalents (METs) from triaxial acceleration at an adaptively changeable sampling rate. This algorithm uses four rates of 32, 16, 8 and 4 Hz. The mode of switching them is decided from synthetic acceleration. Applying this proposed algorithm to […]
Related Product: Actiwave
Publication Date: October 18, 2016
Sprint interval and moderate-intensity cycling training differentially affect adiposity and aerobic capacity in overweight young-adult women
The purpose of the study was to examine the effects of sprint interval training (SIT) and moderate-intensity continuous cycle training (MICT), with equal estimated energy expenditure during training on body composition and aerobic capacity. Body composition measured via dual-energy X-ray absorptiometry and aerobic capacity were assessed following 6 weeks of training in previously inactive overweight/obese […]
Related Product: Actiheart
Publication Date: July 27, 2016
Rational and design of an overfeeding protocol in constitutional thinness: Understanding the physiology, metabolism and genetic background of resistance to weight gain.
Background Constitutional thinness (CT) is a natural state of underweight (13–17.5 kg/m2) without the presence of any eating disorders and abnormal hormonal profile, and with preserved menses in women. We previously conducted a four-week fat overfeeding study showing weight gain resistance in CT women and one of our main results was the identification of an […]
Related Product: Actiheart
Publication Date: July 15, 2016
The association of oxidative stress with arterial compliance and vascular resistance in a bi-ethnic population: the SABPA study
A loss of arterial elasticity increases the risk for cardiovascular events. Oxidative injury to the vessel wall may be one of the underlying mechanisms influencing arterial elasticity. We compared markers of oxidative stress, antioxidant capacity, inflammation, windkessel compliance (Cwk), and total peripheral resistance (TPR) in black and white South Africans. Associations of arterial compliance and […]
Related Product: Actiheart
Publication Date: July 8, 2016
Possible predictors of involuntary weight loss in patients with Alzheimer’s disease
Loss in body mass (∆BM) is a common feature in patients with Alzheimer’s disease (AD). However, the etiology of this phenomenon is unclear. The aim of this cohort study was to observe possible ∆BM in AD patients following a standard institutionalized diet. Secondary objective was to identify possible predictors of ∆BM. To this end, 85 […]
Related Product: Actiheart
Publication Date: June 27, 2016
Energy cost of activities in preschool-aged children
Background: The absolute energy cost of activities in children increases with age due to greater muscle mass and physical capability associated with growth and developmental maturation; however, there is a paucity of data in preschool-aged children. Study aims were 1) to describe absolute and relative energy cost of common activities of preschool-aged children in terms […]
Related Product: Actiheart
Publication Date: June 1, 2016
Strong and persistent effect on liver fat with a Paleolithic diet during a two-year intervention
Background/Objectives: Our objective was to investigate changes in liver fat and insulin sensitivity during a 2-year diet intervention. An ad libitum Paleolithic diet (PD) was compared with a conventional low-fat diet (LFD). Subjects/Methods: Seventy healthy, obese, postmenopausal women were randomized to either a PD or a conventional LFD. Diet intakes were ad libitum. Liver fat […]
Related Product: Actiheart
Publication Date: January 20, 2016
Why do nurses get fatigued? Energy expended, stress or ego depletion?
Background: Fatigue increases throughout the working day and may lead to inefficiency and errors. Why do people become fatigued: because of the cumulative effects of energy expenditure (EE), the stress experienced or the accumulation of ego depleting demands? These questions were examined in nurses assessed in real time over two work shifts. Methods: 100 nurses […]
Related Product: Actiheart
Publication Date: December 13, 2015
Sodium bicarbonate ingestion augments the increase in PGC-1α mRNA expression during recovery from intense interval exercise in human skeletal muscle
We tested the hypothesis that ingestion of sodium bicarbonate (NaHCO3) prior to an acute session of high-intensity interval training (HIIT) would augment signaling cascades and gene expression linked to mitochondrial biogenesis in human skeletal muscle. On two occasions separated by ∼1 wk, nine men (mean ± SD: age 22 ± 2 yr, weight 78 ± […]
Related Product: Actiheart
Publication Date: December 1, 2015
Exercise rehabilitation for peripheral artery disease: An exercise physiology perspective with special emphasis on the emerging trend of home-based exercise
Peripheral artery disease (PAD) is a significant medical concern that is highly prevalent, costly, and deadly. Additionally, patients with PAD have significant impairments in functional independence and health-related quality of life due to leg symptoms and ambulatory dysfunction. Exercise therapy is a primary treatment for patients with PAD, as ambulatory outcome measures improve following a […]
Related Product: Actiheart
Publication Date: November 1, 2015
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
Physical activity energy expenditure vs cardiorespiratory fitness level in impaired glucose metabolism
Aim/hypothesis Little is known about the relative roles of physical activity energy expenditure (PAEE) and cardiorespiratory fitness (CRF) as determinants of glucose regulation. The aim of this study was to examine the associations of PAEE and CRF with markers of glucose metabolism, and to test the hypothesis that CRF modifies the association between PAEE and […]
Related Product: Actiheart
Publication Date: September 5, 2015
Associations of contemporaneous bmi and obesity history with daily patterns of physical activity at age 60–64 years
Background Links between physical activity and body mass index (BMI) are well-recognised. However, the evidence used to quantify this relationship and inform physical activity guidelines is largely based on self-reported activity data. This usually captures specific types of moderate to vigorous activity, less commonly undertaken at older ages, and is subject to reporting bias. In […]
Related Product: Actiheart
Publication Date: August 31, 2015
The effects of energy expenditure rate on work productivity performance at different levels of production standard time
The purpose of this study was to investigate the effects of energy expenditure rate on work productivity performance at different levels of production standard time. [Subjects and Methods] Twenty industrial workers performed repetitive tasks at three different levels of production standard time, normal, hard, and very hard. Work productivity and energy expenditure rate were recorded […]
Related Product: Actiheart
Publication Date: August 27, 2015
Objectively measured sedentary time, physical activity and kidney function in people with recently diagnosed Type 2 diabetes: a prospective cohort analysis
Aim To assess the prospective association between objectively measured physical activity and kidney function over 4 years in people with Type 2 diabetes. Methods Individuals (120 women and 206 men) participating in the ADDITION‐Plus trial underwent assessment of sedentary time (SED‐time), time spent in moderate‐to‐vigorous‐intensity physical activity (MVPA) and total physical activity energy expenditure (PAEE) […]
Related Product: Actiheart
Publication Date: August 18, 2015
Predicting physical activity energy expenditure in wheelchair users with a multisensor device
Aim To assess the error in predicting physical activity energy expenditure (PAEE), using a multisensor device in wheelchair users, and to examine the efficacy of using an individual heart rate calibration (IC) method. Methods 15 manual wheelchair users (36±10 years, 72±11 kg) completed 10 activities: resting, folding clothes, wheelchair propulsion on a 1% gradient (3456 and 7 km/h) […]
Related Product: Actiheart
Publication Date: August 13, 2015
Factors related to total energy expenditure in older adults (Chile)
Aim: to assess Total Energy Expenditure (TEE) in healthy Chilean institutionalized or independently older people. Methods: twenty seven young (27-30 years), 27 institutionalized (> 65 years old) and 27 free-living older (> 65 years old) participants were studied. Body composition was estimated by dual energy X-ray absorptiometry. Physical activity energy expenditure (AEE) and TEE were […]
Related Product: Actiheart
Publication Date: July 8, 2015
Patterns and correlates of objectively measured free-living physical activity in adults in rural and urban Cameroon
Background Urbanisation in sub-Saharan Africa is changing lifestyles and raising non-communicable disease burden. Understanding the underlying pattern of physical activity and its correlates may inform preventive interventions. We examined correlates of objectively-measured physical activity in rural and urban Cameroon. Methods Participants were 544 adults resident in rural (W-156, M-89) or urban (W-189, M-110) regions. Physical […]
Related Product: Actiheart
Publication Date: June 10, 2015
Magnitude and determinants of change in objectively-measured physical activity, sedentary time and sleep duration from ages 15 to 17.5 y in UK adolescents: the ROOTS study
Background Self-reported physical activity (PA) and sleep duration (SLP) change markedly throughout adolescence. We sought to quantify changes in objectively-measured PA, sedentary time (ST) and SLP through adolescence, and to investigate baseline body composition and baseline activity levels as determinants of change. Methods Individually calibrated combined heart rate and movement sensing was used to estimate […]
Related Product: Actiheart
Publication Date: May 14, 2015
A cluster-randomised controlled trial to assess the effectiveness and cost-effectiveness of a childhood obesity prevention programme delivered through schools, targeting 6–7 year old children: the WAVES study protocol
Background There is some evidence that school-based interventions are effective in preventing childhood obesity. However, longer term outcomes, equity of effects and cost-effectiveness of interventions have not been assessed. The aim of this trial is to assess the clinical and cost-effectiveness of a multi-component intervention programme targeting the school and family environment through primary schools, […]
Related Product: Actiheart
Publication Date: May 13, 2015
Energetic adaptations persist after bariatric surgery in severely obese adolescents
Objective Energetic adaptations induced by bariatric surgery have not been studied in adolescents or for extended periods postsurgery. Energetic, metabolic, and neuroendocrine responses to Roux‐en‐Y gastric bypass (RYGB) surgery were investigated in extremely obese adolescents. Methods At baseline and at 1.5, 6, and 12 months post‐baseline, 24‐h room calorimetry, body composition, and fasting blood biochemistries […]
Related Product: Actiheart
Publication Date: February 24, 2015
Electronic monitoring of psychomotor activity as a supplementary objective measure of depression severity
Background: Rating scales used to assess the severity of depression e.g. the Hamilton Depression Rating Scale 17-item (HDRS-17) partly rely on the patient’s subjective experience and reporting. Such subjective measures tend to have low reliability and adding objective measures to complement the assessment of depression severity would be a major step forward. Aims: To investigate […]
Related Product: Actiheart
Publication Date: February 17, 2015
Higher physical activity is associated with lower aortic stiffness but not with central blood pressure: the ADDITION-Pro Study
Physical activity is associated with reduced cardiovascular disease risk. However, improvements in conventional risk factors due to physical activity do not explain its full benefit. Therefore, we examined associations of objectively measured physical activity energy expenditure and intensity with central hemodynamics to provide new insight into the link between physical activity and cardiovascular disease. We […]
Related Product: Actiheart
Publication Date: February 6, 2015
Does a higher incidence of break times in primary schools result in children being more physically active?
BACKGROUND Regular physical activity (PA) has multiple benefits to health; however, the majority of schoolchildren do not reach PA guidelines of 60 minutes of moderate to vigorous PA (MVPA) daily. During the school day, break times are often the only opportunity for children to be physically active. This study investigated PA levels during school breaks […]
Related Product: Actiheart
Publication Date: January 21, 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
Sleep duration and cardiometabolic risk factors among individuals with type 2 diabetes
Objective To examine the association between sleep duration and cardiometabolic risk factors among individuals with recently diagnosed type 2 diabetes (n = 391). Methods Sleep duration was derived using a combination of questionnaire and objective heart rate and movement sensing in the UK ADDITION-Plus study (2002–2007). Adjusted means were estimated for individual cardiometabolic risk factors and clustered […]
Related Product: Actiheart
Publication Date: January 1, 2015
Comparison of telomere length in black and white teachers from South Africa: the sympathetic activity and ambulatory blood pressure in Africans study
Objective: Telomere length is a marker of biological aging that has been linked to cardiovascular disease risk. The black South African population is witnessing a tremendous increase in the prevalence of cardiovascular disease, part of which might be explained through urbanization. We compared telomere length between black South Africans and white South Africans and examined […]
Related Product: Actiheart
Publication Date: January 1, 2015
Effects of physical education on objectively determined physical activity in primary school children—which proportioning is best?
Physical Education (PE) can foster regular physical activity (PA) in children. However, children engage in insufficient moderate to vigorous PA (MVPA) during PE. This study objectively investigated MVPA of children during a single, compared with double PE-period. In 294 children (7.1 ± 0.7 years) PA was objectively assessed. PE periods were determined and PA was […]
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
Exercise and depressive symptoms in adolescents: a longitudinal cohort study
Importance Physical activity (PA) may have a positive effect on depressed mood. However, whether it can act as a protective factor against developing depressive symptoms in adolescence is largely unknown. Objective To investigate the association between objectively measured PA and depressive symptoms during 3 years of adolescence. Design, Setting, and Participants We performed a longitudinal […]
Related Product: Actiheart
Publication Date: December 1, 2014
Linking diet, physical activity, cardiorespiratory fitness and obesity to serum metabolite networks: findings from a population-based study
Objective: It is not yet resolved how lifestyle factors and intermediate phenotypes interrelate with metabolic pathways. We aimed to investigate the associations between diet, physical activity, cardiorespiratory fitness and obesity with serum metabolite networks in a population-based study. Methods: The present study included 2380 participants of a randomly drawn subcohort of the European Prospective Investigation […]
Related Product: Actiheart
Publication Date: November 1, 2014
Leukocyte telomere length and hemostatic factors in a South African cohort: the SABPA Study
Background Incident atherothrombotic disease is predicted by leukocyte telomere length, a marker of biological age, and hemostatic factor levels, indicating a hypercoagulable state. We hypothesized that shorter telomeres are associated with elevated circulating levels of hemostatic factors. Methods We examined 171 South African (black) and 182 Caucasian (white) schoolteachers (mean age ± standard deviation, 48.5 […]
Related Product: Actiheart
Publication Date: September 20, 2014
Development of methods to objectively identify time spent using active and motorised modes of travel to work: how do self-reported measures compare?
Background Active commuting may make an important contribution to population health. Accurate measures of these behaviours are required, but it is unknown how self-reported estimates compare to those derived from objective measures. We sought to develop methods for objectively deriving time spent in specific travel behaviours from a combination of locational and activity data, and […]
Related Product: Actiheart
Publication Date: September 19, 2014
Quantifying fundamental movement skills during active video games
This study sought to explore the type of fundamental movement skills (FMS) performed during Active Video Game (AVG) play, as well as the frequency with which these FMS are performed. In addition, this study aimed to determine the relationship between FMS performance and energy expenditure during 15 min of AVG play across two Microsoft Xbox […]
Related Product: Actiheart
Publication Date: September 1, 2014
The acute effects of interval-vs continuous-walking exercise on glycemic control in subjects with type 2 diabetes: a crossover, controlled study
Context: Glycemic control improves with physical activity, but the optimal exercise mode is unknown. Objective: The objective of the study was to determine whether interval-based exercise improves postprandial glucose tolerance and free-living glycemia more than oxygen consumption- and time duration-matched continuous exercise. Design: This was a crossover, controlled study with trials performed in randomized order. […]
Related Product: Actiheart
Publication Date: September 1, 2014
Normalization of elevated cardiac, kidney, and hemolysis plasma markers within 48 h in Mexican Tarahumara runners following a 78 km race at moderate altitude
Objectives The aim of this study was to examine to what extent extreme endurance exercise results in changes of plasma markers associated with cardiac and renal damage, as well as hemolysis in male, Mexican Tarahumara runners. Methods Ten Tarahumara runners (mean (sd) age of 38 (12) years) participated in a 78 km race in Chihuahua, […]
Related Product: Actiheart
Publication Date: August 22, 2014
Specific appetite, energetic and metabolomics responses to fat overfeeding in resistant-to-bodyweight-gain constitutional thinness
Background: Contrasting with obesity, constitutional thinness (CT) is a rare condition of natural low bodyweight. CT exhibits preserved menstruation in females, no biological marker of undernutrition, no eating disorders but a bodyweight gain desire. Anorexigenic hormonal profile with high peptide tyrosine tyrosine (PYY) was shown in circadian profile. CT could be considered as the opposite […]
Related Product: Actiheart
Publication Date: July 14, 2014
The use of combined heart rate response and accelerometry to assess the level and predictors of physical activity in tuberculosis patients in Tanzania
We assessed the role of tuberculosis (TB) disease and HIV infection on the level of physical activity. A combined heart rate and movement sensor was used to assess habitual physical activity in TB patients and non-TB controls. The association between sputum-negative TB, sputum-positive TB, HIV and physical activity estimates were assessed in multivariable linear regression […]
Related Product: Actiheart
Publication Date: June 1, 2014
Energy expenditure in physical activity of pre-school children measured by means of ActiHeart sensors
ActiHeart®© movement sensors used for measuring physical activity integrate records of cardiac frequency with those obtained by accelerometry from displacement, while disregarding wrong values that can be separately generated by either method. ActiHeart sensors®© were used for measuring daily energy expenditure of 56 pre-school children (Girls: 62.5%; Age: 5.9 ± 0.3 years) every 15 seconds […]
Related Product: Actiheart
Publication Date: June 1, 2014
Prediction of energy expenditure and physical activity in preschoolers
Purpose Accurate, nonintrusive and feasible methods are needed to predict energy expenditure (EE) and physical activity (PA) levels in preschoolers. Herein, we validated cross-sectional time series (CSTS) and multivariate adaptive regression splines (MARS) models based on accelerometry and heart rate (HR) for prediction of EE using room calorimetry and doubly labeled water (DLW), and established […]
Related Product: Actiheart
Publication Date: June 1, 2014
Reliability and validity of a domain-specific last 7-d sedentary time questionnaire
Purpose The objective of this study is to examine test–retest reliability, criterion validity, and absolute agreement of a self-report, last 7-d sedentary behavior questionnaire (SIT-Q-7d), which assesses total daily sedentary time as an aggregate of sitting/lying down in five domains (meals, transportation, occupation, nonoccupational screen time, and other sedentary time). Dutch (DQ) and English (EQ) […]
Related Product: Actiheart
Publication Date: May 16, 2014
Effects of nutritional supplementation for HIV patients starting antiretroviral treatment: randomised controlled trial in Ethiopia
Objectives To determine the effects of lipid based nutritional supplements with either whey or soy protein in patients with HIV during the first three months of antiretroviral treatment (ART) and to explore effects of timing by comparing supplementation at the start of ART and after three months delay. Design Randomised controlled trial. Setting Three public […]
Related Product: Actiheart
Publication Date: May 15, 2014
Levels of physical activity among a nationally representative sample of people in early old age: results of objective and self-reported assessments
Background Detailed assessment of physical activity (PA) in older adults is required to comprehensively describe habitual PA-levels in this growing population segment. Current evidence of population PA-levels is predominantly based on self-report. Methods We examined PA and sedentary behaviour in a nationally representative sample of British people aged 60–64, using individually-calibrated combined heart-rate and movement […]
Related Product: Actiheart
Publication Date: May 3, 2014
Awareness of physical activity in healthy middle-aged adults: a cross-sectional study of associations with sociodemographic, biological, behavioural, and psychological factors
Background Interventions to promote physical activity have had limited success. One reason may be that inactive adults are unaware that their level of physical activity is inadequate and do not perceive a need to change their behaviour. We aimed to assess awareness of physical activity, defined as the agreement between self-rated and objective physical activity, […]
Related Product: Actiheart
Publication Date: May 2, 2014
Multiple behaviour change intervention and outcomes in recently diagnosed type 2 diabetes: the ADDITION-Plus randomised controlled trial
Aims/hypothesis The aim of this study was to assess whether or not a theory-based behaviour change intervention delivered by trained and quality-assured lifestyle facilitators can achieve and maintain improvements in physical activity, dietary change, medication adherence and smoking cessation in people with recently diagnosed type 2 diabetes. Methods An explanatory randomised controlled trial was conducted […]
Related Product: Actiheart
Publication Date: April 24, 2014
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