White Papers and Publications

White papers describe in detail the scientific background of Firstbeat’s technologies with different application areas. The publications section presents studies where Firstbeat solutions have been exploited. The different scientific contexts include for example occupational health care, sleep research, psychotherapy, behavioral research, and sports coaching. Firstbeat methods have been used for research in about 80 universities and research institutions across Europe, North-America, and Australia.

Firstbeat White Papers

Anaerobic Training Effect Assessment

Aerobic Fitness Level (VO₂max) Estimation

Stress and Recovery Analysis Method Based on 24-hour Heart Rate Variability

Accuracy of Firstbeat Bodyguard 2 heart rate monitor

Oxygen Consumption Estimation

Energy Expenditure Estimation

EPOC (Excess Post-Exercise Oxygen Consumption)

Training Effect

Recovery Analysis for Athletic Training Based on Heart Rate Variability

Publications related to:

Physiological modeling, signal processing and mathematical modeling

Oxygen consumption

Energy expenditure

Exercise, training and sports coaching

Well-being, stress, recovery and sleep

Selected scientific publications on Firstbeat technology related to physiological modeling, signal processing and mathematical modeling

Saalasti et al. (2004). Artefact Correction for Heart Beat Interval Data. Pro Bisi Meeting.
→ The RR-interval artefact correction method used by Firstbeat was proven to be fast, very accurate and reliable as it was able to find the correct heart rate level even in situations where the number of artefacts exceeded 50% of the total number of RR-intervals.

Saalasti, S. (2003). Neural networks for heart rate time series analysis. Academic Dissertation. Department of Mathematical Information Technology, University of Jyväskylä, Finland.
→ The study introduced methodology utilizing neural network modeling for interpreting heart rate data, and provided several innovations combining human physiology and mathematical modeling

Pulkkinen et al. (2004). On- and Off Dynamics and Respiration Rate Enhance the Accuracy of Heart Rate Based VO2 Estimation. ACSM congress poster.
→ HR-based VO₂ estimation can be enhanced using information on On- and Off-dynamics and respiration rate that can be derived reliably using beat-to-beat RR-interval data only

Pulkkinen et al. (2005). Energy expenditure can be accurately estimated from HR without individual laboratory calibration. ACSM congress poster.
→ Firstbeat method provided an accurate and practical method for estimating energy expenditure without individual laboratory calibration making it especially suitable for field use

Rusko et al. (2003). Pre-Prediction of EPOC: A Tool for Monitoring Fatigue Accumulation during Exercise? ACSM congress poster.
→ EPOC can be pre-predicted by using only heartbeat data during exercise

Selected scientific publications on Firstbeat technology related to oxygen consumption

Parak et al. (2017). Estimating heart rate, energy expenditure, and physical performance with a wrist photoplethysmographic device during running. JMIR Mhealth and Uhealth 5(7): e97.

→ Firstbeat method was used with a wrist-worn optical heart rate device to estimate energy expenditure (EE) and aerobic fitness (VO2max). Based on the study, Firstbeat method used with optical data and submaximal self-paced outdoor running results in closely similar estimation of VO2max than the reference test in a sports laboratory (MAPE 5.2 %). Energy expenditure was more accurate during moderate to heavy intensity activities (MAPE 6.7 %) than light intensity activities. The authors concluded that optical device, when combined with Firstbeat physiological modeling, may be used for estimation of VO2max and EE.

Mutikainen et al. (2014). Objectively measured physical activity in Finnish employees: a cross-sectional study. BMJ Open, Sports and exercise medicine 4:12.
→ Firstbeat method used as a novel validated methodology to study intensity-specific physical activity in a large sample of working age individuals, with detailed associations between intensity-specific physical activity, gender, age, body mass index, and the type of day (workday vs day off).

Smolander et al. (2011). Estimating oxygen consumption from heart rate and heart rate variability without individual calibration. Clinical Physiology and Functional Imaging.
→ Firstbeat VO₂ estimation method is sufficiently accurate for field-use

Montgomery et al. (2009). Validation of Heart Rate Monitor-Based Predictions of Oxygen Uptake and Energy Expenditure. Journal of Strength and Conditioning Research.
→ Firstbeat VO₂ estimation method vary ~ 6% in submaximal–maximal running compared to calibrated laboratory gas exchange system, and less if accurate background parameters are used

Smolander at al. (2007). A new heart rate variability-based method for the estimation of oxygen consumption without individual laboratory calibration: Application example on postal workers.
→ Firstbeat method was compared to traditional HR-only method to estimate energy expenditure, and found useful for estimating VO₂ in the field without laboratory calibration

Smolander et al. (2007). A Novel Method for Using Heart Rate Variability Data for Estimation of Oxygen Consumption and Energy Expenditure: A Validation. ECSS congress. Abstract.
→ Firstbeat method provides adequate estimates of breathing frequency and on/off-kinetics of HR and VO₂, and consequently the oxygen consumption and energy expenditure

Selected scientific publications on Firstbeat technology related to energy expenditure

Parak et al. (2017). Estimating heart rate, energy expenditure, and physical performance with a wrist photoplethysmographic device during running. JMIR Mhealth and Uhealth 5(7): e97.

Finni et al. (2014). Exercise for ﬁtness does not decrease the muscular inactivity time during normal daily life. Scand J Med Sci Sports, 24: 211–219.
→ Energy expenditure provided by Firstbeat method was used as a reference for daily energy expenditure and compared to muscle activity data [EMG] during active and non-active days

Salonen et al. (2013) Heart Rate Variability Recordings are a Valid Non-Invasive Tool for Evaluating Soldiers’ Stress. J Def Stud Resour Manage 2:1.
→ Firstbeat methods were utilized in assessing soldiers’ energy expenditure and cardiovascular autonomic modulation during 72-hour military field training and shown applicable method for assessing soldiers’ stress

Selected scientific publications on Firstbeat technology related to exercise, training and sports coaching

Mikkola et al. (2012). Nocturnal Heart Rate and Heart Rate Variability Based Training Load Monitoring, a Case Study of an Elite Junior XC Skier During a Glacier Training Camp. 2nd International Congress on Science and Nordic Skiing, 28-31 May, Vuokatti, Finland.
→ Firstbeat method seems to be practical tool for assessing training induced stress over an athlete although recovery as well as HR and HRV responses are individual

Vesterinen, et al. (2011). Heart rate variability in prediction of individual adaptation to endurance training in recreational endurance runners. Scandinavian Journal of Medicine & Science in Sports.
→ Firstbeat method was used to analyze nocturnal HRV which may serve as a useful method to assess individual adaptation to prolonged endurance training

Hynynen & Nummela (2010). A three year follow-up study of endurance performance and nocturnal HRV of an international level race-walker. EA innovation awards.
→ Regular nocturnal HRV analysis with Firstbeat method was utilized for international level race-walker’s training and it was found useful for assessing training and racing induced stress and an individual variation in recovery

Luhtanen et al. (2007). Physical loading, stress and recovery in a youth soccer tournament. VI^th congress on science in football. Abstract.
→ Firstbeat method was applied for soccer in assessing load of matches and training [by EPOC] and recovery during sleep [recovery index]

Vänttinen et al. (2007). Heart Rate and Match Analysis of Finnish Junior Football Players. VI^th congress on science in football. Poster.
→ Match analysis and physiological analysis [HR and EPOC by Firstbeat method] was conducted for junior soccer players in different age groups revealing higher relative playing intensity in older age groups during a match

Häyrinen et al. (2007). An Evaluation of Physical Loading, Recovery and Stress in Youth Soccer. Science for Success II congress. Poster.
→ The study showed that Firstbeat methods work well in team sports and the results revealed that the playing position and characteristics of the match affect significantly to EPOC values, which typically peaked during the first half of the match

Vänttinen et al. (2007). Practical Experiences from Measuring Exercise Intensity and Recovery State with Heart Rate Monitoring in Team Sport. International Symposium Computer Science in Sport. Poster.
→ Firstbeat methods were applied into team sports [soccer] and found applicable for following-up of training, quantifying the impact of matches, optimizing preparation, and for teaching players to recognize their overall stress in life

Wünsch et al. (2006) Suunto t6 – A Reliable and Accurate Measuring Instrument for Performance Diagnostics and Training Control. University of Bayeroit, report.
→ Firstbeat method utilized in Suunto t6 wrist computer is appropriate for performance diagnostics and training control, and might highly contribute to successful training

Wünsch et al. (2006). Suunto t6 –ein zuverlässiges und genaues Messgerät zur Leistungsdiagnostik und Trainingssteuerung? Untersuchung zur Validität und Reliabilität anhand von Labortests auf dem Fahrradergometer und Feldtests.
→ Firstbeat method utilized in Suunto t6 wrist computer was shown to be valid and reliable in laboratory and field tests for measuring physiological parameters

Wünsch et al. (2005). Examination of Suunto t6 regarding Validity and Reliability.
→ Firstbeat method utilized in Suunto t6 wrist computer provides reliable values during a maximum stress test until exhaustion for ventilation, respiration rate, oxygen consumption and energy consumption

Rusko (2004). Influence of Increased Duration or Intensity on Training Load as evaluated by EPOC and TRIMPS. ACSM congress presentation.
→ EPOC can give dynamic information on the training load and allows calculation of time needed for recovery i.e. decrease of EPOC to resting level

Selected scientific publications on well-being, stress, recovery and sleep

Föhr et al. (2015). Subjective stress, objective heart rate variability-based stress, and recovery on workdays among overweight and psychologically distressed individuals: a cross-sectional study. Journal of Occupational Medicine and Toxicology, 10:39
→ Subjective stress was directly associated with objective stress and inversely with objective recovery measured with the Firstbeat method. The authors suggested that objective stress assessment provides an additional aspect to stress evaluation.

Teisala et al. (2014). Associations of physical activity, fitness, and body composition with heart rate variability–based indicators of stress and recovery on workdays: a cross-sectional study. Journal of Occupational Medicine and Toxicology, 9:16.
→ Physical activity, fitness level and body composition were associated with stress and recovery by the Firstbeat method. In addition, objective stress measured with Firstbeat method was associated with self-reported occupational burnout symptoms. The authors concluded that the results support the usability of the Firstbeat method in the evaluation of stress and recovery

Uusitalo et al. (2011). Heart rate variability related to effort at work. Appl Ergon, 42: 830–838.
→ Firstbeat relaxation was negatively associated with effort at work measured with effort-reward imbalance questionnaire [ERI] assessing chronic work stress

Pietilä et al. (2015). Exploratory analysis of associations between individual lifestyles and heart rate variability -based recovery during sleep. EMBC’15. 37th Annual International Conference of the IEEE Engineering in Medicine and Biology Society. (Peer reviewed).
→ The study explored the importance of different lifestyle factors on Firstbeat’s HRV-based recovery during sleep on a large sample. Alcohol consumption, physical activity, fitness, and sleep duration play significant role in recovery.

Lappalainen et al. (2014). The effectiveness and applicability of different lifestyle interventions for enhancing well-being: the study design for a randomized controlled trial for persons with metabolic syndrome risk factors and psychological distress. BMC Public Health, 14: 310.
→ Firstbeat lifestyle assessment was used as an objective physiological method for measuring stress and recovery in randomized controlled trial examining the effectiveness, applicability, and acceptability of different lifestyle interventions with individuals having symptoms of metabolic syndrome and psychological distress

Lappalainen et al. (2013). Feasibility of a Personal Health Technology-Based Psychological Intervention for Men with Stress and Mood Problems: Randomized Controlled Pilot Trial. JMIR Res Protoc. 2(1): e1.
→ Firstbeat lifestyle assessment was used in a well-being intervention utilizing several technology tools and rated as the most useful intervention component by the participants

Jaatinen et al. (2014). Effects of daily intake of yoghurt enriched with bioactive components on chronic stress responses: a double-blinded randomized controlled trial. International Journal of Food Sciences and Nutrition, 65 (4): 507-514.
→ The study used Firstbeat method as objective physiological method to assess stress when investigating whether yoghurt enriched with bioactive components have stress reducing effects as compared to normal yoghurt.

Kaipainen et al (2010). Web, mobile and monitoring technologies in self-management of psychophysiological well-being: usage and user experiences. Proceedings of the IADIS International Conference e-Health, Freiburg, Germany, 167–177.
→ The study explored a concept in which large amount of different technologies were utilized for improving well-being of participants, and where face-to-face intervention meetings and Firstbeat measurements with personal feedback were perceived as the two most important components of the whole concept

Happonen et al. (2009). P4Well concept to empower self-management of psychophysiological well-being and load recovery. Proceedings of the 3rd International Conference on Pervasive Computing Technologies for Healthcare, London, UK, 1–3.
→ The study described a well-being concept that utilized also Firstbeat methods [mobile coach and lifestyle assessment] and which was designed with a driving principle that an individual is the best master of her own wellness and targeted to empower her for realizing the fact

Hyrkkänen & Vartiainen (2012) Heart Rate Variability Measurements in Mobile Work. Communications in Computer and Information Science Volume 313, pp 60-67. In Proceedings book: Exploring the Abyss of Inequalities 4th International Conference on Well-Being in the Information Society, WIS 2012. Turku, Finland, August 22-24, 2012. Eriksson-Backa K, Luoma A, Krook E (Eds.).
→ HRV-based Firstbeat assessment was found to be especially suitable for mobile employees with mobile working mode who have difficulties on controlling their work–life balance

Myllymäki et al. (2012). Effects of exercise intensity and duration on nocturnal heart rate variability and sleep quality. Eur J Appl Physiol 112(3): 801–809.
→ Firstbeat relaxation was decreased during sleep after demanding exercises [vigorous or long] compared to control sleep without changes in actigraphy or subjective sleep quality

Myllymäki et al. (2010). Effects of vigorous late-night exercise on sleep quality and cardiac autonomic activity. J Sleep Res 20, 146–153.
→ Firstbeat relaxation was diminished during sleep after intensive late-evening exercise without changes in polysomnographic or movement-based sleep quality

Feldt et al. (2007). The Associations between Self-Rated Affective Well-Being and Physiological Indicators of Stress and Relaxation among Cleaning Staff. European Congress of Work and Organizational Psychology.
→ Contentment at work indicating subjective experiences of relaxation was linked to low physiological stress and high physiological relaxation measured with Firstbeat method

Rönkä et al. (2006). The Associations between Physiological Recovery Indicators during Sleep and Self-Reported Work Stressors. Nordic Ergonomics Society congress. Abstract.
→ Longer relaxation time during sleep was associated with less perceived work stressors on the next day

Kinnunen et al. (2006). Stress and relaxation based on heart rate variability: Associations with self-reported mental strain and differences between waking hours and sleep. Nordic Ergonomics Society congress. Abstract.
→ Firstbeat method is a promising tool for occupational health care sector as it provides general scoring describing stress and relaxation state for work, leisure time, and sleep

Rusko et al. (2006). Stress and relaxation during sleep and awake time, and their associations with free salivary cortisol after awakening. Nordic Ergonomics Society congress. Abstract.
→ Significant correlations were found between awakening cortisol variables and variables of stress and relaxation with Firstbeat method during sleep

Antila et al. (2005). Associations of Phychological Self-Assesments and Heart Rate Variability in Long Term Measurements at Home. European Medical & Biological Engineering Conference.
→ The study revealed significant associations between stress measured with Firstbeat method and self-assessments of stress