Peter Düking

Comparison of Non-Invasive Individual Monitoring of the Training and Health of Athletes with Commercially Available Wearable Technologies

Athletes adapt their training daily to optimize performance, as well as avoid fatigue, overtraining and other undesirable effects on their health. To optimize training load, each athlete must take his/her own personal objective and subjective characteristics into consideration and an increasing number of wearable technologies (wearables) provide convenient monitoring of various parameters. Accordingly, it is important to help athletes decide which parameters are of primary interest and which wearables can monitor these parameters most effectively. Here, we discuss the wearable technologies available for non-invasive monitoring of various parameters concerning an athletes training and health. On the basis of these considerations, we suggest directions for future development. Furthermore, we propose that a combination of several wearables is most effective for accessing all relevant parameters, disturbing the athlete as little as possible, and optimizing performance and promoting health.

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

Instant biofeedback provided by wearable sensor technology can help to optimize exercise and prevent injury and overuse

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.

The SpeedCourt: Reliability, Usefulness, and Validity of a New Method to Determine Change-of-Direction Speed

PURPOSE To determine the reliability, usefulness, and validity of 3 different change-of-direction tests on a SpeedCourt (SC(CODT)) in team-sport players. METHODS For reliability and usefulness, 30 players (16 female and 14 male; age 19 ± 3 y, height 169 ± 30 cm, body mass 70 ± 11 kg) performed 3 SC(CODT)s differing in duration (7-45 s) on 3 occasions 1 wk apart. The total sprint times (TT) and time to change direction (TCD) were analyzed for each SC(CODT). For validity, 14 players performed the Illinois Agility Test (IAT) and 505 test on a separate occasion. RESULTS TT for all SC(CODT)s is reliable (ICC > .79, CV < 5%), useful (TE < SWC0.5), and valid (IAT r > .71, P < .05; 505 test r > .54, P < .05). SC(CODT) variable TCD may be useful (TE = SWC0.5) but shows limited reliability with ICC >.65 and a CV >5%. CONCLUSIONS All SC(CODT)s are reliable, useful, and valid to detect moderate performance changes regarding TT, with limited reliability for TCD. The quality of assessment improves when players are well familiarized with the SC(CODT).

A SWOT Analysis of the Use and Potential Misuse of Implantable Monitoring Devices by Athletes

A SWOT Analysis of the Use and Potential Misuse of Implantable Monitoring Devices by Athletes

Integrated Framework of Load Monitoring by a Combination of Smartphone Applications, Wearables and Point-of-Care Testing Provides Feedback that Allows Individual Responsive Adjustments to Activities of Daily Living

Athletes schedule their training and recovery in periods, often utilizing a pre-defined strategy. To avoid underperformance and/or compromised health, the external load during training should take into account the individual’s physiological and perceptual responses. No single variable provides an adequate basis for planning, but continuous monitoring of a combination of several indicators of internal and external load during training, recovery and off-training as well may allow individual responsive adjustments of a training program in an effective manner. From a practical perspective, including that of coaches, monitoring of potential changes in health and performance should ideally be valid, reliable and sensitive, as well as time-efficient, easily applicable, non-fatiguing and as non-invasive as possible. Accordingly, smartphone applications, wearable sensors and point-of-care testing appear to offer a suitable monitoring framework allowing responsive adjustments to exercise prescription. Here, we outline 24-h monitoring of selected parameters by these technologies that (i) allows responsive adjustments of exercise programs, (ii) enhances performance and/or (iii) reduces the risk for overuse, injury and/or illness.

The Potential Usefulness of Virtual Reality Systems for Athletes: A Short SWOT Analysis

Virtual reality (VR) systems (Neumann et al., 2017), which are currently receiving considerable attention from athletes, create a twoor three-dimensional environment in the form of emulated pictures and/or video-recordings where in addition to being mentally present, the athlete even often feels like he/she is there physically as well. As she/he interacts with and/or reacts to this environment, movement is captured by sensors, allowing the system to provide feedback. As with every newly evolving technology related to human movement and behavior, it is important to be aware of the strengths, weaknesses, opportunities and threats (SWOT) associated with the use of this particular type of technology. SWOT analyses are widely utilized for strategic planning of developmental processes (Pickton and Wright, 1998; Tao and Shi, 2016) and it is of great interest to consider whether VR systems should be adopted by athletes or not. Aspects more inherent to the employed technologies of VR systems, and aspects more related to the application of VR systems with athletes are considered as strength/weaknesses and opportunities/threats, respectively. Analogously, SWOT analysis concerning another emerging technology involving sensors of individual parameters (i.e., “implantables”) has been performed (Sperlich et al., 2017).

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.