Instant Biofeedback Provided by Wearable Sensor Technology Can Help to Optimize Exercise and Prevent Injury and Overuse

Source at https://doi.org/10.3389/fphys.2017.00167 With great interest, we have been following the developing variety and popularity of commercially available wearable sensor technologies, as well as the discussion concerning their usefulness for improving fitness and health (Duking et al., 2016; Halson et al., 2016; Sperlich and Holmberg,2016). Although many of these devices may not necessarily fulfill scientific criteria for quality (Sperlich and Holmberg, 2016) or may pose a threat to the security of personal data (Austen, 2015 ), we would like to emphasize here that many individuals who seek to improve their health or physical performance do so on their own, without the guidance of professionals to design their fitness training. Although professional guidance is, of course, important, such individuals and, especially beginners, would find instantaneous (bio)feedback beneficial for optimal adaptation and prevention of overuse or injury. We believe wearable sensor technologies, in conjunction with appropriate (mobile) applications, data mining and machine learning algorithms, can provide biofeedback that is useful in many ways

Differences in physical match performance and injury occurence before and after the COVID-19 break in professional European soccer leagues: a systematic review

Purpose. Due of the Covid-19 pandemic, matches and soccer-specific training were suspended for several weeks, matches after resumption were congested, and substitutions per team and game increased from three to five. Therefore, the aim of this review was to examine possible differences in physical match performance and injuries between before and after the Covid-19 induced break of matches and training in professional male European soccer leagues during the 2019/2020 season. Methods. A systematic search identified all scientifically peer-reviewed publications involving elite male soccer players competing in the European leagues which reported physical match performance variables such as total running distance and running distance at different speed zones and/or injury parameters pre and post Covid-19 induced break. Results. In total, 11 articles were included, which were coming from German Bundesliga, Polish Ekstraklasa, Croatian HNL, Spanish La Liga, and Italian Serie A. In all studies investigating the German Bundesliga, most parameters of physical match performance remained unaffected (0.08 ≤ p ≤ 0.82; -0.15 ≤ ES 0.15), while studies investigating the Polish Ekstraklasa (p ≤ 0.03; -0.27 ≤ ES -0.18), Croatian HNL (p ≤ 0.04; -1.42 ≤ ES ≤ 1.44), Spanish La Liga (p ≤ 0.017; -0.32 ≤ ES ≤ 5.5), and Italian Serie A (p ≤ 0.014; -1.01 ≤ ES 0.24) showed a decrease in most parameters of physical match performance after the Covid-19 break. Injury rates where only investigated by studies targeting the German Bundesliga and Italian Serie A. In the majority of studies (3 out of 4 studies), there occurred no difference in injuries between pre and post Covid-19 break (p > 0.05; ES = N/A). Conclusion. Results indicate that Bundesliga teams maintained physical match performance during the 9-weeks break in matches and 3-weeks break in group training, whereas a longer match and group training interruption up to 15 weeks and 8 weeks, respectively, in the other leagues appeared to lead to a decreased physical match performance. Regarding injuries, we speculate that the increase of substitutions from 3 to 5 substitutions per game might prevent an increase in injury occurrence during matches. The underlying studies’ results provide hints for possible upcoming unexpected interruptions with respect to optimal physical preparations for the resumption of matches and a congested schedule to maintain physical match performance, or for possible rule changes such as 5 instead of 3 substitutions to avoid physical overload during congested match schedules

Criterion-Validity of Commercially Available Physical Activity Tracker to Estimate Step Count, Covered Distance and Energy Expenditure during Sports Conditions

Background: In the past years, there was an increasing development of physical activity tracker (Wearables). For recreational people, testing of these devices under walking or light jogging conditions might be sufficient. For (elite) athletes, however, scientific trustworthiness needs to be given for a broad spectrum of velocities or even fast changes in velocities reflecting the demands of the sport. Therefore, the aim was to evaluate the validity of eleven Wearables for monitoring step count, covered distance and energy expenditure (EE) under laboratory conditions with different constant and varying velocities.Methods: Twenty healthy sport students (10 men, 10 women) performed a running protocol consisting of four 5 min stages of different constant velocities (4.3; 7.2; 10.1; 13.0 km·h−1), a 5 min period of intermittent velocity, and a 2.4 km outdoor run (10.1 km·h−1) while wearing eleven different Wearables (Bodymedia Sensewear, Beurer AS 80, Polar Loop, Garmin Vivofit, Garmin Vivosmart, Garmin Vivoactive, Garmin Forerunner 920XT, Fitbit Charge, Fitbit Charge HR, Xaomi MiBand, Withings Pulse Ox). Step count, covered distance, and EE were evaluated by comparing each Wearable with a criterion method (Optogait system and manual counting for step count, treadmill for covered distance and indirect calorimetry for EE).Results: All Wearables, except Bodymedia Sensewear, Polar Loop, and Beurer AS80, revealed good validity (small MAPE, good ICC) for all constant and varying velocities for monitoring step count. For covered distance, all Wearables showed a very low ICC (<0.1) and high MAPE (up to 50%), revealing no good validity. The measurement of EE was acceptable for the Garmin, Fitbit and Withings Wearables (small to moderate MAPE), while Bodymedia Sensewear, Polar Loop, and Beurer AS80 showed a high MAPE up to 56% for all test conditions.Conclusion: In our study, most Wearables provide an acceptable level of validity for step counts at different constant and intermittent running velocities reflecting sports conditions. However, the covered distance, as well as the EE could not be assessed validly with the investigated Wearables. Consequently, covered distance and EE should not be monitored with the presented Wearables, in sport specific conditions

Wearable technology in the sports medicine clinic to guide the return-to-play and performance protocols of athletes following a COVID-19 diagnosis

The coronavirus disease 2019 (COVID-19) pandemic has enabled the adoption of digital health platforms for self-monitoring and diagnosis. Notably, the pandemic has had profound effects on athletes and their ability to train and compete. Sporting organizations worldwide have reported a significant increase in injuries manifesting from changes in training regimens and match schedules resulting from extended quarantines. While current literature focuses on the use of wearable technology to monitor athlete workloads to guide training, there is a lack of literature suggesting how such technology can mediate the return to sport processes of athletes infected with COVID-19. This paper bridges this gap by providing recommendations to guide team physicians and athletic trainers on the utility of wearable technology for improving the well-being of athletes who may be asymptomatic, symptomatic, or tested negative but have had to quarantine due to a close exposure. We start by describing the physiologic changes that occur in athletes infected with COVID-19 with extended deconditioning from a musculoskeletal, psychological, cardiopulmonary, and thermoregulatory standpoint and review the evidence on how these athletes may safely return to play. We highlight opportunities for wearable technology to aid in the return-to-play process by offering a list of key parameters pertinent to the athlete affected by COVID-19. This paper provides the athletic community with a greater understanding of how wearable technology can be implemented in the rehabilitation process of these athletes and spurs opportunities for further innovations in wearables, digital health, and sports medicine to reduce injury burden in athletes of all ages. © The Author(s) 2023

Monitoring parameters of external and internal load to individualize training procedures with wearable technology

Trainingsprozesse sollten individualisiert und situativ an das Verhältnis zwischen Belastung bzw. Beanspruchung und Erholung angepasst werden, um optimale physiologische Adaptionen und Leistungsverbesserungen zu erzielen. Dazu müssen verschiedene Belastungs- und Beanspruchungsmarker erfasst, analysiert und interpretiert werden. Durch technologische Entwicklungen im Bereich tragbarer Sensorik (Wearables) ist es inzwischen möglich, eine Vielzahl an relevanten Belastungs- und/oder Beanspruchungsmarkern in der Praxis zu erheben. Übergeordnetes Ziel der Dissertation war, den Einsatz von Wearables zum Monitoring von Belastungs- und/oder Beanspruchungsmarkern zur individualisierten und situativ angepassten Steuerung von Trainingsprozessen aus trainingswissenschaftlicher Perspektive zu untersuchen. Es wurden sechs Studien durchgeführt. Es konnte gezeigt werden, 1. dass einige, aber nicht alle relevanten Belastungs- und Beanspruchungsmarker mit derzeit kommerziell erhältlichen Wearables erfasst werden können (Studie 1), 2. dass viele Marker welche von Wearables erhoben werden nicht auf Reliabilität und/oder Validität hin untersucht worden sind und/oder dass sich die Reliabilität und/oder Validität zwischen Wearables und verschiedenen sportlichen Aktivitäten unterscheidet und deren Anwendung daher limitiert ist (Studie 1,2,3), 3. dass die Apple Watch Series 4, gefolgt von der Polar Vantage V, die derzeit beste Validität zur Erfassung der Herzfrequenz bei Athleten während verschiedenen Laufintensitäten aufweist (Studie 3). 4. dass bei Läufern ein individualisiert gesteuerter Trainingsprozess (basierend auf Daten des autonomen Nervensystems erfasst durch Wearables) zu größeren Leistungsverbesserungen und ausgewählten submaximalen physiologischen Adaptionen führt, als ein nicht individualisiert gesteuerter Trainingsprozess (Studie 4), 5. dass ein System benötigt wird, welches verschiedene Technologien zur weiteren Ausdifferenzierung eines individualisiert gesteuerten Trainingsprozesses vereint (Studie 5). Es bleiben weitere Fragen offen die Klärung bedürfen, wenn Wearables zum Monitoring von Belastungs- und/oder Beanspruchungsmarkern zur individualisierten Steuerung von Trainingsprozessen verwendet werden sollen. Zu diesen Fragen gehören unter anderem: 1. Welche Auswahl an Belastungs- und/oder Beanspruchungsmarkern sowie Wearables in Abhängigkeit der Sportart, der Athletenpopulation und der Trainingsphase optimal ist, 2. ob die Erfassung von großen Datenmengen sowie die Anwendung von Big Data Analysen einen Mehrwert bei der individuellen Steuerung von Trainingsprozessen liefern, 3. wie ein (Bio-)Feedback optimal gestaltet wird, 4. wie Trainer mit Wearables interagieren, 5. welche Abänderung des Trainingsprozesses in Abhängigkeit der jeweiligen Sportart und Athletenpopulation auf Basis welches Parameters optimal ist.Training prescription should be individualized and responsively adjusted to balance training load and recovery in order to promote optimal physiological adaptations and enhance performance. This procedure requires monitoring of external and internal load markers. Due to the technological developments in the field of wearable sensor technologies (wearables), a variety of markers can be monitored. The overall goal of this thesis was to investigate the use of wearables for monitoring external and internal load markers for the individualization and responsive adjustments of training processes from a training science perspective. Six studies were conducted. The main findings are as follows: 1) some, but not all, external and internal load markers can be monitored with commercially available wearables (study 1), 2) many markers which are monitored by wearables have not been examined for reliability and/or validity and/or that the reliability and/or validity differs between wearables and between different sporting activities which limits their usefulness (study 1, 2, 3), 3) the Apple Watch Series 4, followed by the Polar Vantage V, revealed the highest validity to monitor heart rate of athletes during different running intensities (study 3), 4) in runners individualization and responsive adjustments of training processes (based on data from the autonomic nervous system monitored by wearables) leads to greater performance improvements and selected submaximal physiological adaptations than a predefined training prescription (study 4), 5) a system needs to be developed which combines different Wearables for further differentiation of an individualization and responsively training process (study 5). There are questions that need clarification if Wearables shall be used to monitor external or internal load markers for the individualization and responsive adjustments of training processes. These questions include: 1) Which selection of external and internal load markers and wearables is optimal depending on the type of sport, the athlete population and the training phase? 2) Does the acquisition of large amounts of data and the application of big data analyses such as the artificial intelligence adds value in the individualization and responsive adjustments of training processes? 3) How is the (bio-)feedback optimally established? 4) How do coaches interact with data derived from wearables? 5) Which responsive adjustment of the training process is optimal, depending on the respective sport and athlete population

Multi-Directional Sprint Training Improves Change-Of-Direction Speed and Reactive Agility in Young Highly Trained Soccer Players

The aim of this study was to evaluate the effect of a repeated sprint training with multi-directional change-of-direction (COD) movements (RSmulti) compared to repeated shuttle sprints (RSS) on variables related to COD speed and reactive agility. Nineteen highly-trained male U15 soccer players were assigned into two groups performing either RSmulti or RSS. For both groups, each training session involved 20 repeated 15 s sprints interspersed with 30 s recovery. With RSmulti the COD movements were randomized and performed in response to a visual stimulus, while the RSS involved predefined 180° COD movements. Before and following the six training sessions, performance in the Illinois agility test (IAT), COD speed in response to a visual stimulus, 20 m linear sprint time and vertical jumping height were assessed. Both groups improved their performance in the IAT (p < 0.01, ES = 1.13; p = 0.01, ES = 0.55). The COD speed in response to a visual stimulus improved with the RSmulti (p < 0.01, ES = 1.03), but not the RSS (p = 0.46, ES = 0.28). No differences were found for 20 m sprint time (P=0.73, ES = 0.07; p = 0.14, ES = 0.28) or vertical jumping height (p = 0.46, ES = 0.11; p = 0.29, ES = 0.12) for the RSmulti and RSS, respectively. In conclusion, performance in the IAT improved with the RSmulti as well as RSS. With the RSmulti however, the COD movements are performed in response to a visual stimulus, which may result in specific adaptations that improve COD speed and reactive agility in young highly trained soccer players

Acute physiological, biomechanical, and perceptual responses of runners wearing downward-curved carbon fiber insoles

In a randomized controlled cross-over study ten male runners (26.7 ± 4.9 years; recent 5-km time: 18:37 ± 1:07 min:s) performed an incremental treadmill test (ITT) and a 3-km time trial (3-km TT) on a treadmill while wearing either carbon fiber insoles with downwards curvature or insoles made of butyl rubber (control condition) in light road racing shoes (Saucony Fastwitch 9). Oxygen uptake, respiratory exchange ratio, heart rate, blood lactate concentration, stride frequency, stride length and time to exhaustion were assessed during ITT. After ITT, all runners rated their perceived exertion, perceived shoe comfort and perceived shoe performance. Running time, heart rate, blood lactate levels, stride frequency and stride length were recorded during, and shoe comfort and shoe performance after, the 3-km TT. All parameters obtained during or after the ITT did not differ between the two conditions [range: p = 0.188 to 0.948 (alpha value: 0.05); Cohen's d = 0.021 to 0.479] despite the rating of shoe comfort showing better scores for the control insoles (p = 0.001; d = −1.646). All parameters during and after the 3-km TT showed no differences (p = 0.200 to 1.000; d = 0.000 to 0.501) between both conditions except for shoe comfort showing better scores for control insoles (p = 0.017; d = −0.919). Running with carbon fiber insoles with downwards curvature did not change running performance or any submaximal or maximal physiological or biomechanical parameter and perceived exertion compared to control condition. Shoe comfort is impaired while running with carbon fiber insoles. Wearing carbon fiber insoles with downwards curvature during treadmill running is not beneficial when compared to running with control insoles

Discovery of a Sweet Spot on the Foot with a Smart Wearable Soccer Boot Sensor That Maximizes the Chances of Scoring a Curved Kick in Soccer

This paper provides the evidence of a sweet spot on the boot/foot as well as the method for detecting it with a wearable pressure sensitive device. This study confirmed the hypothesized existence of sweet and dead spots on a soccer boot or foot when kicking a ball. For a stationary curved kick, kicking the ball at the sweet spot maximized the probability of scoring a goal (58–86%), whereas having the impact point at the dead zone minimized the probability (11–22%). The sweet spot was found based on hypothesized favorable parameter ranges (center of pressure in x/y-directions and/or peak impact force) and the dead zone based on hypothesized unfavorable parameter ranges. The sweet spot was rather concentrated, independent of which parameter combination was used (two- or three-parameter combination), whereas the dead zone, located 21 mm from the sweet spot, was more widespread