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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Dynamic personalized human body energy expenditure: Prediction using time series forecasting LSTM models
Dynamic human energy expenditure (EE) consists of energy costs for resting metabolism, food digestion, physical activity, and thermoregulation. Currently, multiple models predict EE mainly concerning physical activity, thus, discarding other factors contributing to the dynamic variation of EE. This paper aimed to demonstrate that (i) a dynamic human body EE prediction requires the time series […]
Related Product: Actiheart
Publication Date: September 7, 2023
A self-paced walk test for individual calibration of heart rate to energy expenditure
Introduction Estimating free-living physical activity (PA) with continuous heart rate (HR) monitoring is challenging due to individual variation in the relationship between HR and energy expenditure. This variation can be captured through individual calibration with graded exercise tests, but structured tests with prescribed load requires medical screening and are not always feasible in population settings. […]
Related Product: Actiheart
Publication Date: September 1, 2023
Post-exercise dietary macronutrient composition modulates components of energy balance in young, physically active adults
Abstract The effectiveness of exercise to reduce body mass is typically modest, partially due to energy compensation responses which may be linked to energy substrate availability around exercise. The present study aimed to investigate the effect of manipulating post-exercise energy substrate availability (high carbohydrate/low fat [HCLF] or low carbohydrate/high fat [LCHF] energy replacement) on energy […]
Related Product: Actiheart
Publication Date: August 10, 2023
UDAMA: Unsupervised Domain Adaptation through Multi-discriminator Adversarial Training with Noisy Labels Improves Cardio-fitness Prediction
Deep learning models have shown great promise in various healthcare monitoring applications. However, most healthcare datasets with high-quality (gold-standard) labels are small-scale, as directly collecting ground truth is often costly and time-consuming. As a result, models developed and validated on small-scale datasets often suffer from overfitting and do not generalize well to unseen scenarios. At […]
Related Product: Actiheart
Publication Date: July 31, 2023
Energy expenditure and intensity of ritual jumping–dancing in male Maasai
Objectives Traditional jumping–dance rituals performed by Maasai men involve prolonged physical exertion that may contribute significantly to overall physical activity level. We aimed to objectively quantify the metabolic intensity of jumping–dance activity and assess associations with habitual physical activity and cardiorespiratory fitness (CRF). Methods Twenty Maasai men (18–37 years) from rural Tanzania volunteered to participate in […]
Related Product: Actiheart
Publication Date: May 3, 2023
Cardiovascular risk and kidney function profiling using conventional and novel biomarkers in young adults: the African-PREDICT study
Background Low- and middle-income countries experience an increasing burden of chronic kidney disease. Cardiovascular risk factors, including advancing age, may contribute to this phenomenon. We (i) profiled cardiovascular risk factors and different biomarkers of subclinical kidney function and (ii) investigated the relationship between these variables. Methods We cross-sectionally analysed 956 apparently healthy adults between 20 […]
Related Product: Actiheart
Publication Date: April 13, 2023
Exercise and Artery Function in Twins: Sex Differences in a Cross-Over Trial
Background: Physical activity reduces cardiovascular risk, partly via direct effects on the arterial wall. We hypothesized that vascular function responses would be modality-specific, sex-dependent, and express a high degree of heritability. Methods: We recruited 90 same-sex twins (31 monozygotic, 14 dizygotic dizygotic pairs; 25.8±6.0 years) and randomized 70 (25 monozygotic, 10 dizygotic) to complete, as […]
Related Product: Actiheart
Publication Date: April 10, 2023
Assessment of Energy and Nutrient Intake and the Intestinal Microbiome (ErNst Study): Protocol and Methods of a Cross-sectional Human Observational Study
Background: On the national level, nutritional monitoring requires the assessment of reliable representative dietary intake data. To achieve this, standardized tools need to be developed, validated, and kept up-to-date with recent developments in food products and the nutritional behavior of the population. Recently, the human intestinal microbiome has been identified as an essential mediator between […]
Related Product: Actiheart
Publication Date: April 7, 2023
The effect of caloric restriction on genetical pathways
Energy restriction is defined as reducing nutrient intake without dragging the organism into malnutrition. Energy restriction is preferred because it is a non-genetic intervention that increases life expectancy. Nicotinamide adenine dinucleotide (NAD+) and adenosine monophosphate (AMP) levels, which are the indicators of intracellular energy deficiency, increase with energy restriction. The increase in NAD+ level stimulates […]
Related Product: Actiheart
Publication Date: March 21, 2023
Evidence for protein leverage in a general population sample of children and adolescents
Background/Objectives The strong regulation of protein intake can lead to overconsumption of total energy on diets with a low proportion of energy from protein, a process referred to as protein leverage. The protein leverage hypothesis posits that protein leverage explains variation in energy intake and potentially obesity in ecological settings. Here, we tested for protein […]
Related Product: Actiheart
Publication Date: February 16, 2023
The association between plasma zinc concentrations and markers of glucose metabolism in adults in Cameroon
An abnormal Zn status has been suggested to play a role in the pathogenesis of type 2 diabetes. However, epidemiological studies of the relationship between plasma Zn concentrations and diabetes are sparse and inconclusive. We aimed to investigate the association between plasma Zn concentrations and glycaemic markers (fasting glucose, 2-h glucose and homeostatic model assessment […]
Related Product: Actiheart
Publication Date: January 25, 2023
Case Report: Effect of low energy availability and training load on sleep in a male combat sport athlete
Purpose: The aim of this case report was to describe the sleep responses in a male combat sport athlete, who was engaging in both chronic (CWL) and acute (AWL) weight loss practices in order to reduce body mass for a national competition. Methods: During the first seven weeks of training (Phases 1 and 2), the […]
Related Product: Actiheart
Publication Date: January 6, 2023
Breaking up sitting with short frequent or long infrequent physical activity breaks does not lead to compensatory changes in appetite, appetite-regulating hormones or energy intake
The aim of this study was to determine the appetite-related responses to breaking up prolonged sitting with physical activity bouts differing in frequency and duration among adult females. Fourteen sedentary females aged 34 ± 13 years with a body mass index of 27.1 ± 6.3 kg/m2 (mean ± SD) took part in a randomised crossover […]
Related Product: Actiheart
Publication Date: January 4, 2023
Short, frequent high-intensity physical activity breaks reduce appetite compared with a continuous moderate-intensity exercise bout
A single exercise session can affect appetite-regulating hormones and suppress appetite. The effects of short, regular physical activity breaks across the day on appetite are unclear. This study investigated the effects of breaking up sitting with high-intensity physical activity vs a single bout of moderate-intensity exercise and prolonged sitting on appetite control. In this randomised […]
Related Product: Actiheart
Publication Date: December 22, 2022
Longitudinal cardio-respiratory fitness prediction through wearables in free-living environments
Cardiorespiratory fitness is an established predictor of metabolic disease and mortality. Fitness is directly measured as maximal oxygen consumption (VO2max), or indirectly assessed using heart rate responses to standard exercise tests. However, such testing is costly and burdensome because it requires specialized equipment such as treadmills and oxygen masks, limiting its utility. Modern wearables capture […]
Related Product: Actiheart
Publication Date: December 2, 2022
Timing of physical activity in relation to liver fat content and insulin resistance
Aims/hypothesis We hypothesised that the insulin-sensitising effect of physical activity depends on the timing of the activity. Here, we examined cross-sectional associations of breaks in sedentary time and timing of physical activity with liver fat content and insulin resistance in a Dutch cohort. Methods In 775 participants of the Netherlands Epidemiology of Obesity (NEO) study, […]
Related Product: Actiheart
Publication Date: November 1, 2022
Assessment of cardiovascular load among hotel room cleaners
Hotel room cleaners are a vulnerable population at risk for cardiovascular disease. To evaluate their workload heart rate (HR), % heart rate reserve (%HRR), blood pressure (BP), metabolic equivalent (MET), and energy expenditure (EE) were measured over two workdays and two off-workdays. The mean age was 45.5 (SD 8.2) years with a mean 10.4 (SD […]
Related Product: Actiheart
Publication Date: September 23, 2022
A randomized placebo-controlled trial of nicotinamide riboside and pterostilbene supplementation in experimental muscle injury in elderly individuals
BACKGROUND. During aging, there is a functional decline in the pool of muscle stem cells (MuSCs) that influences the functional and regenerative capacity of skeletal muscle. Preclinical evidence has suggested that nicotinamide riboside (NR) and pterostilbene (PT) can improve muscle regeneration, e.g., by increasing MuSC function. The objective of this study was to investigate if […]
Related Product: Actiheart
Publication Date: August 23, 2022
Association between circulating 25-hydroxyvitamin D and cardiometabolic risk factors in adults in rural and urban settings
Background An inverse association between vitamin D status and cardiometabolic risk has been reported but this relationship may have been affected by residual confounding from adiposity and physical activity due to imprecise measures of these variables. We aimed to investigate the relationship between serum 25-hydroxyvitamin D (25(OH)D) and cardiometabolic risk factors, with adjustment for objectively-measured […]
Related Product: Actiheart
Publication Date: July 29, 2022
Energy expenditure and time spent on physical activity in Costa Rican schoolchildren with overweight or obesity by means of the Actiheart accelerometer
Objective: To determine the energy expenditure and time spent on physical activities in Costa Rican overweight or obese schoolchildren in free-living conditions. Methodology: Participants were 31 boys and 13 girls aged 6 to 9 years old (7.6 ± 1.03 years) with overweight or obesity; nutritional status was established by BMI. The variables of the study […]
Related Product: Actiheart
Publication Date: June 1, 2022
The relationship between physical activity, body fatness and metabolic syndrome in urban South African school teachers: The sympathetic activity and ambulatory blood pressure in Africans study
Background: Globally, the prevalence of metabolic syndrome (MS) is rising because of increased levels of physical inactivity and obesity. In South Africa, information about teachers’ physical activity (PA), body fatness and MS is limited. Aim: To assess the relationship between PA, body fatness and MS in urban South African teachers. Setting: The study setting was […]
Related Product: Actiheart
Publication Date: May 30, 2022
Dynamics of metabolic rate in male individuals due to the meal and regular office activities
Metabolic rate is one of the main parameters affecting the thermal balance of the human body and perception of thermal comfort. Typically, we consider a constant value for a specific type of activity (sitting quiet, standing, etc.) despite the time of the day and body built of a person. In this study, we challenged this […]
Related Product: Actiheart
Publication Date: May 25, 2022
Studies of twin responses to understand exercise THerapy (STRUETH): Cerebrovascular function
We studied monozygotic (MZ) and dizygotic (DZ) twin pairs following resistance (RES) and endurance (END) training to assess genetic and environmental contributions to cerebrovascular function. Cerebrovascular function (rest, autoregulation, hypercapnia, exercise) was assessed in 86 healthy same-sex MZ (30 pairs) and DZ (13 pairs) twins, who underwent 3 months of END and RES. Carbon dioxide […]
Related Product: Actiheart
Publication Date: May 13, 2022
Longitudinal cardio-respiratory fitness prediction through free-living wearable sensors
Cardiorespiratory fitness is an established predictor of metabolic disease and mortality. Fitness is directly measured as maximal oxygen consumption (VO2max), or indirectly assessed using heart rate response to a standard exercise test. However, such testing is costly and burdensome, limiting its utility and scalability. Fitness can also be approximated using resting heart rate and self-reported […]
Related Product: Actiheart
Publication Date: May 6, 2022
Soluble (Pro) renin Receptor Is Adversely Associated with Indices of Left Ventricular Structure and Function: The African-PREDICT Study
This study aims to compare soluble (pro)renin receptor [s(P)RR] levels between black and white adults and to explore the associations of left ventricular (LV) structure and function with s(P)RR in the total and ethnicity-stratified groups. The study sample included 1172 apparently healthy black (n = 587) and white (n = 585) participants of the African-PREDICT […]
Related Product: Actiheart
Publication Date: April 25, 2022
Exercise Intervention Changes the Perceptions and Knowledge of Non-Communicable Disease Risk Factors among Women from a Low-Resourced Setting
We employed the Health Belief Model (HBM) as a theoretical lens to explore the influence of an exercise intervention on the perceptions and knowledge of modifiable risk factors for non-communicable diseases (NCDs) among women from a low-resource setting in South Africa. We used a mixed-methods design, gathering qualitative and quantitative data at baseline (n = […]
Related Product: Actiheart
Publication Date: March 15, 2022
Health‐related quality of life for normal glycaemia, prediabetes and type 2 diabetes mellitus: cross‐sectional analysis of the ADDITION‐PRO study
Aims We estimated and compared health-related quality of life for individuals with normal glucose tolerance, prediabetes and diabetes. Methods Participants in the ADDITION-PRO study, Denmark, who attended a health assessment between 2009 and 2011, and who completed the 3-level EuroQoL 5-dimensions (EQ-5D-3L) questionnaire were included. For the present study, they were classified as normal glucose […]
Related Product: Actiheart
Publication Date: March 6, 2022
Descriptive epidemiology of cardiorespiratory fitness in UK adults: The Fenland Study
Background Cardiorespiratory fitness is rarely measured in population studies. Most studies of fitness do not examine differences by population subgroups or seasonal trends. Methods We used a validated submaximal exercise test to measure fitness in 5976 women and 5316 men, residing in England. We expressed fitness as maximal oxygen consumption per kilogram total body mass […]
Related Product: Actiheart
Publication Date: March 1, 2022
The association of sickle‐cell trait with β‐cell dysfunction and physical activity in adults living with and without HIV in Tanzania
This study aimed to investigate sickle cell trait (SCT) associations with physical activity, markers of insulin secretion and resistance, and glucose among people living with HIV infection (PLWH), both antiretroviral therapy (ART) naive and experienced, and HIV-uninfected adults. This was a cross-sectional study conducted in Mwanza, Northwestern Tanzania. We used data of 668 participants attained […]
Related Product: Actiheart
Publication Date: February 15, 2022
Assessment of activity energy expenditure during competitive golf: The effects of bag carrying, electric or manual trolleys
Golf is a sport played around the globe, with an estimated 42.6 million people playing within the United Kingdom and United States of America alone. To date there is limited data on the energy expenditure of golf. The present study assessed the activity energy expenditure (AEE) of 16 high-standard (handicap under 5) golfers who completed […]
Related Product: Actiheart
Publication Date: January 30, 2022
Levels and correlates of physical activity and capacity among HIV-infected compared to HIV-uninfected individuals
Introduction In the HIV-infected individuals, physical activity improves physical strength, quality of life and reduces the risk of developing non-communicable diseases. In Sub-Saharan Africa, HIV-infected patients report being less active compared to HIV-uninfected individuals. We assessed the levels and correlates of objectively measured physical activity and capacity among HIV-infected antiretroviral therapy (ART)-naive individuals compared to […]
Related Product: Actiheart
Publication Date: January 21, 2022
Breakfast Consumption Suppresses Appetite but Does Not Increase Daily Energy Intake or Physical Activity Energy Expenditure When Compared with Breakfast Omission in Adolescent Girls Who Habitually Skip Breakfast: A 7-Day Randomised Crossover Trial
With concerns that adolescent girls often skip breakfast, this study compared the effects of breakfast consumption versus breakfast omission on free-living physical activity (PA) energy expenditure (PAEE) and dietary intakes among adolescent girls classified as habitual breakfast skippers. The participants went through two 7-day conditions in a trial with a crossover design: daily standardised breakfast […]
Related Product: Actiheart
Publication Date: November 26, 2021
Resistance but not endurance exercise training induces changes in cerebrovascular function in healthy young subjects
It is generally considered that regular exercise maintains brain health and reduces the risk of cerebrovascular diseases such as stroke and dementia. Since the benefits of different “types” of exercise are unclear, we sought to compare the impacts of endurance and resistance training on cerebrovascular function. In a randomized and crossover design, 68 young healthy […]
Related Product: Actiheart
Publication Date: October 11, 2021
Sex-Specific Relationship between the Cardiorespiratory Fitness and Plasma Metabolite Patterns in Healthy Humans—Results of the KarMeN Study
Cardiorespiratory fitness (CRF) represents a strong predictor of all-cause mortality and is strongly influenced by regular physical activity (PA). However, the biological mechanisms involved in the body’s adaptation to PA remain to be fully elucidated. The aim of this study was to systematically examine the relationship between CRF and plasma metabolite patterns in 252 healthy […]
Related Product: Actiheart
Publication Date: July 17, 2021
Effects of short-term graded dietary carbohydrate intake on intramuscular and whole-body metabolism during moderate-intensity exercise
Altering dietary carbohydrate (CHO) intake modulates fuel utilization during exercise. However, there has been no systematic evaluation of metabolic responses to graded changes in short-term (< 1 week) dietary CHO intake. Thirteen active men performed interval running exercise combined with isocaloric diets over 3 days before evaluation of metabolic responses to 60-min running at 65% […]
Related Product: Actiheart
Publication Date: May 27, 2021
Adolescent Endurance Runners Exhibit Suboptimal Energy Availability and Intakes of Key Nutrients
Backgroud: Despite the evidence of an elevated prevalence of low bone mass in adolescent endurance runners, reports on dietary intake in this population is limited. Objectives: This study aimed to evaluate energy availability (EA) and dietary intake among 72 (n = 60 female, n = 12 male) high school cross-country runners. Methods: The sample consisted of a combined dataset […]
Related Product: Actiheart
Publication Date: May 25, 2021
Socio‐economic inequalities, modifiable lifestyle risk factors and retinal vessel calibers: The African‐PREDICT Study
Objective Lifestyle risk factors vary between socioeconomic status (SES) groups and may influence cardiovascular function differently. The retinal microvasculature allows for monitoring early changes in cardiovascular health, therefore we investigated whether retinal vessel calibers associate differently with modifiable risk factors in different SES groups. Methods We included 1064 young adults (aged 20-30 years) grouped by […]
Related Product: Actiheart
Publication Date: May 19, 2021
Physical activity attenuates postprandial hyperglycaemia in homozygous TBC1D4 loss-of-function mutation carriers
Aims/hypothesis The common muscle-specific TBC1D4 p.Arg684Ter loss-of-function variant defines a subtype of non-autoimmune diabetes in Arctic populations. Homozygous carriers are characterised by elevated postprandial glucose and insulin levels. Because 3.8% of the Greenlandic population are homozygous carriers, it is important to explore possibilities for precision medicine. We aimed to investigate whether physical activity attenuates the […]
Related Product: Actiheart
Publication Date: April 29, 2021
Joint associations between objectively measured physical activity volume and intensity with body-fatness. The Fenland Study
Background/Objectives Physical activity energy expenditure (PAEE) represents the total volume of all physical activity. This can be accumulated as different underlying intensity profiles. Although volume and intensity have been studied in isolation, less is known about their joint association with health. We examined this association with body-fatness in a population-based sample of middle-aged British women […]
Related Product: Actiheart
Publication Date: March 28, 2021
Testosterone and exercise: Effects on fitness, body composition and strength in middle-to-older aged men with low-normal serum testosterone levels
As men age, serum testosterone (T) concentrations decrease, as do fitness, strength and lean mass. Whether testosterone treatment confers additive benefit to reverse these changes when combined with exercise training in middle-to-older aged men remains unclear. We assessed the effects of T treatment and exercise, alone and in combination, on aerobic capacity (VO2peak), body composition […]
Related Product: Actiheart
Publication Date: March 19, 2021
Changes in Energy Expenditure, Dietary Intake, and Energy Availability Across an Entire Collegiate Women’s Basketball Season
The purpose of this study was to identify changes in energy expenditure and dietary intake across an entire women’s basketball season. On 5 different occasions across the competitive season, female collegiate basketball players (19.8 ± 1.3 years, 173.9 ± 13.6 cm, 74.6 ± 9.1 kg, 27.1 ± 3.2% fat, 53.9 ± 6.4 ml·kg−1·min−1, n = […]
Related Product: Actiheart
Publication Date: March 1, 2021
Associations of physical activity, sedentary time, and diet quality with biomarkers of inflammation in children
We investigated the associations of physical activity (PA), sedentary time (ST), and diet quality with biomarkers of inflammation in 390 children (192 girls, 198 boys) aged 6–8 years. PA energy expenditure (PAEE), light PA, moderate PA (MPA), vigorous PA (VPA), moderate-to-vigorous PA (MVPA), and ST were assessed by combined movement and heart rate sensor. Finnish […]
Related Product: Actiheart
Publication Date: February 19, 2021
A Stress Syndrome Prototype Reflects Type 3 Diabetes and Ischemic Stroke Risk: The SABPA Study
Type 3 diabetes (T3D) accurately reflects that dementia, e.g., Alzheimer’s disease, represents insulin resistance and neurodegeneration in the brain. Similar retinal microvascular changes were observed in Alzheimer’s and chronic stressed individuals. Hence, we aimed to show that chronic stress relates to T3D dementia signs and retinopathy, ultimately comprising a Stress syndrome prototype reflecting risk for […]
Related Product: Actiheart
Publication Date: February 18, 2021
Effect of high‐intensity interval training on cardiometabolic component risks in persons with paraplegia: Protocol for a randomized controlled trial
Individuals with a spinal cord injury (SCI) are at an increased risk of developing cardiovascular disease and present with a multitude of elevated cardiometabolic component risks. Although upper‐body exercise appears an effective strategy to improve some of these outcomes, the effectiveness of high‐intensity interval training (HIIT) has yet to be determined for this population. Therefore, […]
Related Product: Actiheart
Publication Date: February 18, 2021
Effectiveness of Minimal Contact Interventions: An RCT
Introduction Around 23% of adults worldwide are insufficiently active. Wearable devices paired with virtual coaching software could increase physical activity. The effectiveness of 3 minimal contact interventions (paper-based physical activity diaries, activity trackers, and activity trackers coupled with virtual coaching) in increasing physical activity energy expenditure and cardiorespiratory fitness were compared over 12 weeks among […]
Related Product: Actiheart
Publication Date: February 18, 2021
Independent and combined associations between fast-food outlet exposure and genetic risk for obesity: a population-based, cross-sectional study in the UK
Background Characteristics of the built environment, such as neighbourhood fast-food outlet exposure, are increasingly recognised as risk factors for unhealthy diet and obesity. Obesity also has a genetic component, with common genetic variants explaining a substantial proportion of population-level obesity susceptibility. However, it is not known whether and to what extent associations between fast-food outlet […]
Related Product: Actiheart
Publication Date: February 15, 2021
β-Lactoglobulin Elevates Insulin and Glucagon Concentrations Compared with Whey Protein—A Randomized Double-Blinded Crossover Trial in Patients with Type Two Diabetes Mellitus
Whey protein is an insulinotropic fraction of dairy that reduces postprandial glucose levels in patients with type 2 diabetes mellitus (T2DM). We have recently shown that β-lactoglobulin (BLG), the largest protein fraction of whey, elevates insulin concentrations compared with iso-nitrogenous whey protein isolate (WPI) in healthy individuals. We therefore hypothesized that BLG pre-meals would lower […]
Related Product: Actiheart
Publication Date: January 22, 2021
Measuring Physical Activity Levels During instructional Settings for Children with Autism Spectrum Disorder
A growing number of children with autism spectrum disorder (ASD) may not possess the motor skills needed to be physically active. In order to address these needs, Camp Nugget is held each summer with the goal of providing quality individualized physical activity instruction to children with disabilities 5 through 12 years of age. The program […]
Related Product: Actiheart
Publication Date: January 1, 2021
Studies of Twin Responses to Understand Exercise Therapy (STRUETH): Body Composition
Purpose We studied individual variability in exercise responses in twins. We hypothesized that 1) endurance (END) training would reduce fat mass whereas resistance (RES) training would increase lean mass, 2) individuals who did not respond to one modality would respond to the other, and 3) cross-sectional heritability estimates would be higher than estimates based on […]
Related Product: Actiheart
Publication Date: January 1, 2021
Day and night changes in energy expenditure of patients on automated peritoneal dialysis
Rationale Automated peritoneal dialysis (APD) treatment for end-stage kidney disease affords patients a degree of autonomy in everyday life. Clinical investigations of their energy expenditure (EE) are usually based on resting EE, which could mask day and night variations in EE. The aim of this study, therefore, was to compare the components of EE in […]
Related Product: Actiheart
Publication Date: November 28, 2020
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