Hannu Kinnunen

Hannu Kinnunen
  • Doctor of Science (Technology); MSc (Biophysics)
  • CEO and Chief Innovator at Hannu Kinnunen Innovation Oy

About

68
Publications
37,608
Reads
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2,162
Citations
Current institution
Hannu Kinnunen Innovation Oy
Current position
  • CEO and Chief Innovator
Additional affiliations
February 2014 - May 2021
Oura
Position
  • Chief Scientific Officer
May 1996 - February 2014
Polar Electro Oy
Position
  • Principal Investigator

Publications

Publications (68)
Article
Full-text available
The physiological underpinnings of the necessity of sleep remain uncertain. Recent evidence suggests that sleep increases the convection of cerebrospinal fluid (CSF) and promotes the export of interstitial solutes, thus providing a framework to explain why all vertebrate species require sleep. Cardiovascular, respiratory and vasomotor brain pulsati...
Article
Full-text available
Lockdowns imposed to stem the spread of COVID-19 massively disrupted the daily routines of many worldwide, but studies to date have been mostly confined to observations within a limited number of countries, based on subjective reports and surveys from specific time periods during the pandemic. We investigated associations between lockdown stringenc...
Article
Full-text available
Consumer-grade sleep trackers represent a promising tool for large scale studies and health management. However, the potential and limitations of these devices remain less well quantified. Addressing this issue, we aim at providing a comprehensive analysis of the impact of accelerometer, autonomic nervous system (ANS)-mediated peripheral signals, a...
Article
Introduction Lockdowns imposed to stem the spread of COVID-19 have disrupted the lifestyles of many worldwide, but studies to date are mostly confined to observations within a limited number of countries, based on subjective reports and survey from a narrow time window. In the present study, we investigate associations between the severity of lockd...
Preprint
Full-text available
Lockdowns imposed to stem the spread of COVID-19 massively disrupted the daily routines of many worldwide, but studies to date are mostly confined to observations within a limited number of countries, based on subjective reports and survey from specific time periods during the pandemic. We investigated associations between lockdown stringency and o...
Preprint
Full-text available
Lockdowns imposed to stem the spread of COVID-19 massively disrupted the daily routines of many worldwide, but studies to date are mostly confined to observations within a limited number of countries, based on subjective reports and survey from specific time periods during the pandemic. We investigated associations between lockdown stringency and o...
Article
Background Heart rate variability (HRV) is an important marker of overall health and especially cardiovascular health. Decreased HRV has been associated with reduced vagal control of heart rate and with adverse outcome in several studies. Purpose The purpose of this study was to investigate the impact of demographic factors (age and sex) and under...
Preprint
Full-text available
Sleep is known to increase the convection of interstitial brain metabolites along with cerebrospinal fluid (CSF). We used ultrafast magnetic resonance encephalography (MREG BOLD ) to quantify the effect of sleep on physiological (vasomotor, respiratory and cardiac) brain pulsations driving the CSF convection in humans. Transition to electroencephal...
Article
Introduction Resting heart rate (RHR) associates with cardiovascular fitness, acute and chronic health status, and mental stress. Nightly sleep provides an excellent measurement time because ambient conditions are constant and confounding factors are controlled. Relatively low RHR is seen as a mark of better health, performance, and recovery levels...
Article
Full-text available
Objective: To validate the accuracy of the Oura ring in the quantification of resting heart rate (HR) and heart rate variability (HRV). Background: Wearable devices have become comfortable, lightweight, and technologically advanced for assessing health behavior. As an example, the novel Oura ring integrates daily physical activity and nocturnal...
Article
Full-text available
Abstract Background Body temperature is a common method in menstrual cycle phase tracking because of its biphasic form. In ambulatory studies, different skin temperatures have proven to follow a similar pattern. The aim of this pilot study was to assess the applicability of nocturnal finger skin temperature based on a wearable Oura ring to monitor...
Conference Paper
Full-text available
Resting heart rate (RHR) and heart rate variability (HRV) reflect the autonomic control of cardiac chronotropic activity, and they associate with cardiovascular fitness, acute and chronic health status, and mental stress. Relatively low RHR and relatively high HRV are generally seen as marks of better health, performance, and recovery levels. Never...
Article
Full-text available
Introduction Wrist-mounted motion sensors can quantify the volume and intensity of physical activities, but little is known about their long-term validity. Our aim was to validate a wrist motion sensor in estimating daily energy expenditure, including any change induced by long-term participation in endurance and strength training. Supplemental hea...
Article
Purpose: To compare training load and energy expenditure during an 8-week military BT period among individuals having different fitness level using objective measurements in an authentic environment. Methods: Thirty-four voluntary male conscripts (age 19.1±0.3 years) were divided into three training groups (inactive, moderate, active) by their r...
Article
Introduction Sleep is one of the main pillars of our health and wellbeing. Both short and long duration of sleep has been associated with obesity, diabetes, hypertension and cardiovascular diseases and even with greater risk of death. Nevertheless, the duration of the sleep is not the only quantity affecting the perceived quality of sleep but it ca...
Conference Paper
Full-text available
We spend almost one third of our life in sleep. Sleep is one of the main contributors to our life and wellbeing. Sleep disorders are know to have adverse health effects but studies have also shown that too little or too much sleep is correlated with a greater risk of death. Sleep trackers have introduced new tools for sleep related studies by provi...
Article
Full-text available
Introduction The ultimate target of wearable sleep measurement is to help people improve both their sleep and subsequently their daily performance. The timing of the sleep-wake cycle is partially based on chronotypes, which has a strong genetic component, and also affects daytime physical and cognitive performance. One potential means would be bett...
Article
Full-text available
Introduction The beat of a healthy heart shows significant variation among the time intervals between heartbeats. Heart rate variability (HRV) consists of periodic and aperiodic changes in the duration of the cardiac “QRS-wave” cycle. Greater nocturnal HRV has been linked with better sleep quality in healthy and clinical populations. Measurement of...
Conference Paper
Full-text available
The volume and intensity of training load and energy expenditure during military basic training (BT) period is poorly known. In order to maintain and enhance aerobic performance, a certain amount of physical activity is required. On the other hand, excessive and prolonged physical activity leads to an overreaching state, which is followed by decrea...
Patent
Full-text available
An apparatus in connection with a fitness exercise of a person, including means for processing multidimensional electrocardiographic data of the person, the multidimensional electrocardiographic data comprising at least two spatially separately measured electrocardiographic signal components, means for forming a vectorcardiographic measure on the b...
Patent
Full-text available
There is provided electronic device, comprising: a receiving unit configured to receive heart rate data generated by a heart rate measuring system; a calculation unit configured to calculate heart rate variation data on the basis of the received heart rate data. The electronic device further comprises: a processing unit configured to analyse the ca...
Article
In this study, the correlations between blood lactate concentration (BLC), different vector electrocardiogram (VECG) parameters, ventilatory parameters and heart rate during exercise and recovery periods were investigated. The aim was to clarify the relationships between VECG parameters and different exercise intensity markers. Six (25–37 years old...
Patent
Full-text available
The invention relates to a method, a user-specific performance monitor and a computer program for determining the user's performance. In the method, the performance power of a physical exercise is determined by means of user movement data registered by the user-specific performance monitor. Further, the exertion level corresponding to the performan...
Article
Full-text available
We assessed the ability of the Polar activity recorder (AR) to measure energy expenditure (EE) during military training. Twenty-four voluntary male conscripts participated in the study and wore an AR on the non-dominant wrist 24 h a day for 7 d. The AR analyzed and stored the frequency of hand movements (f_hand) into memory at 1 min intervals. The...
Article
Full-text available
Previous military studies have shown an energy deficit during a strenuous field training course (TC). This study aimed to determine the effects of energy bar supplementation on energy balance, physical activity (PA), physical performance and well-being and to evaluate ad libitum fluid intake during wintertime 8-day strenuous TC. Twenty-six men (age...
Article
Full-text available
High intensity cycling training increases oxidative capacity in skeletal muscles and improves insulin sensitivity. The present study compared the effect of eight weeks of sprint interval running (SIT) and continuous running at moderate intensity (CT) on insulin sensitivity and cholesterol profile in young healthy subjects (age 25.2 ± 0.7; VO(2max)...
Article
Full-text available
We hypothesised that habitual physical activity (PA) together with progressive endurance training contributes to the differences in training response (Δ[V(·)]O(2max)) in healthy and physically active male participants. Twenty volunteers (age 30±3 years and [V(·)]O(2max) 54±7 ml·kg⁻¹·min⁻¹) participated in an eight-week training program which includ...
Article
We hypothesized that increased oxidative stress and disrupted redox balance may be predisposing factors and markers for overreaching (OR). The study's purpose was to examine whether oxidative stress markers and antioxidant status and physical fitness are related to OR during an 8-wk military basic training (BT) period. Oxidative stress and antioxid...
Article
Full-text available
The last 4 weeks of basic military training are very stressful. We tested the hypothesis that changes in cardiac autonomic function during this period are associated with changes in maximal oxygen uptake and/or serum hormonal concentrations in male conscripts (n=22). Cardiac vagal autonomic function was assessed by measuring the high-frequency (0.1...
Conference Paper
Full-text available
The study concentrates on tracking swimming exercises based on the data of 3D accelerometer and shows that human activities can be tracked accurately using low sampling rates. The tracking of swimming exercise is done in three phases: first the swimming style and turns are recognized, secondly the number of strokes are counted and thirdly the inten...
Article
The purpose was (a) to study the effect of an 8-week Finnish military basic training period (BT) on physical fitness, body composition, mood state, and serum biochemical parameters among new conscripts; (b) to determine the incidence of overreaching (OR); and (c) to evaluate whether initial levels or training responses differ between OR and noOR su...
Conference Paper
Full-text available
The aim of the study was to investigate the correlations between blood lactate concentration, different vector ECG (VECG) parameters, ventilatory parameters and heart rate during exercise and recovery periods. Six (25-37 years old) non athlete, healthy, male subjects participated in the study. All subjects performed two different bicycle er-gospiro...
Article
Full-text available
To test the utility of HR variability (HRV) in daily exercise prescription in moderately active (approximately two exercises per week) men and women. A total of 21 men and 32 women were divided into standard training (ST: males = 7 and females = 7), HRV-guided training (HRV-I: males = 7 and females = 7; HRV-II: females = 10), and control (males = 7...
Article
Full-text available
Heart rate (HR) variability (HRV) during ambulatory recordings may be affected by individual differences in daily physical activity (PA). However, the influence of various levels of PA on different measures of HRV is not exactly known. We examined the association between simultaneously measured HRV and objective PA data obtained with an acceleromet...
Article
Aging alters cardiac autonomic function, which may contribute to a higher risk of cardiac events. Spectral measures of HR variability (HRV) and fractal-like behavior of HR are considered as markers of a healthy heart. The present study examined the effects of combining endurance and strength training compared with endurance or strength training alo...
Conference Paper
Full-text available
Automatic recognition of activities using time series data collected from exercise can facilitate development of applications that motivate people to exercise more frequently and actively. This article presents a method for recognizing nine different everyday sport activities, such as running, walking, aerobics and Nordic walking, using only two-di...
Conference Paper
Full-text available
This paper introduces a novel algorithm for estimating energy expenditure during physical activity. The estimation is based on acceleration data measured from a wrist-worn accelerometer. Simultaneous measurements of acceleration and oxygen consumption using a biaxial accelerometer and a breath gas analyzer were made during four different activities...
Article
Large interindividual variation in maximal heart rate (HRmax) may not be accounted for by age alone. In order to evaluate a novel method in the prediction of HRmax, this study examined the profile of HR variability (HRV) during exercise in 40-67 years old men (n = 74). R-R intervals were recorded during supine rest and during a graded exercise test...
Article
Full-text available
One of the goals of exercise prescription is the use of easily understandable physical activities to improve physical fitness. Lack of study designs investigating self-administered programs utilizing exercise telemetry monitors (ETM) compared to a no exercise telemetry monitors (NETM) guided exercise programs exist. The aim of the study was to dete...
Conference Paper
Full-text available
This article presents an approach to estimating exer- cise energy expenditure based on acceleration measure- ments from a wrist-worn biaxial sensor. The method uses the linear mixed model that makes it possible to model both between-subject and within-subject variation in energy expenditure. More precisely, a random-intercepts model is used. The va...
Article
Full-text available
Purpose of this study was to test utility of heart rate variability (HRV) in daily endurance exercise prescriptions. Twenty-six healthy, moderately fit males were randomized into predefined training group (TRA, n = 8), HRV-guided training group (HRV, n = 9), and control group (n = 9). Four-week training period consisted of running sessions lasting...
Article
Full-text available
Large individual differences in the responsiveness of cardiorespiratory fitness (VO2peak) to endurance training have been observed in healthy subjects. We tested the hypothesis that subjects with a poor responsiveness to endurance training might benefit from resistance training in terms of aerobic fitness. The study population consisted of sedentar...
Article
Background In large population studies, comparisons of physical activity, self-rated fitness, and measured aerobic fitness are seldom reported. Measuring aerobic fitness is time-consuming and expensive, thus alternative methods are needed. Objectives To investigate the recently established Polar Fitness Test (PFT) as a method to predict maximal ox...
Article
Full-text available
By definition, measurement of maximal aerobic power (VO2max) requires a maximal effort of the subject tested. However, in daily practice of sportsmedicine it would often be useful to estimate VO2max as accurately as possible also in resting state. Traditionally, characteristics like age, body weight and height as well as amount of exercise have bee...
Article
The ambulatory electrocardiogram (ECG) is an important medical tool, not only for diagnosis of adverse cardiac events, but also to predict the risk of such events occurring. The 24-hour ambulatory ECG has certain problems and drawbacks because the signal is corrupted by noise from various sources and also several other conditions which may alter th...

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