A Novel Adaptive Spectrum Noise Cancellation Approach for Enhancing Heartbeat Rate Monitoring in a Wearable Device

This paper presents a novel approach, Adaptive Spectrum Noise Cancellation (ASNC), for motion artifacts removal in Photoplethysmography (PPG) signals measured by an optical biosensor to obtain clean PPG waveforms for heartbeat rate calculation. One challenge faced by this optical sensing method is the inevitable noise induced by movement when the user is in motion, especially when the motion frequency is very close to the target heartbeat rate. The proposed ASNC utilizes the onboard accelerometer and gyroscope sensors to detect and remove the artifacts adaptively, thus obtaining accurate heartbeat rate measurement while in motion. The ASNC algorithm makes use of a commonly accepted spectrum analysis approaches in medical digital signal processing, discrete cosine transform, to carry out frequency domain analysis. Results obtained by the proposed ASNC have been compared to the classic algorithms, the adaptive threshold peak detection and adaptive noise cancellation. The mean (standard deviation) absolute error and mean relative error of heartbeat rate calculated by ASNC is 0.33 (0.57) beats·min-1 and 0.65%, by adaptive threshold peak detection algorithm is 2.29 (2.21) beats·min-1 and 8.38%, by adaptive noise cancellation algorithm is 1.70 (1.50) beats·min-1 and 2.02%. While all algorithms performed well with both simulated PPG data and clean PPG data collected from our Verity device in situations free of motion artifacts, ASNC provided better accuracy when motion artifacts increase, especially when motion frequency is very close to the heartbeat rate

The dose-response relationship between training load and aerobic fitness in academy rugby union players

© 2018 Human Kinetics, Inc. Purpose: To identify the dose-response relationship between measures of training load (TL) and changes in aerobic fitness in academy rugby union players. Method: Training data from 10 academy rugby union players were collected during a 6-wk in-season period. Participants completed a lactate-threshold test that was used to assess VO 2 max, velocity at VO 2 max, velocity at 2 mmol/L (lactate threshold), and velocity at 4 mmol/L (onset of lactate accumulation; vOBLA) as measures of aerobic fitness. Internal-TL measures calculated were Banister training impulse (bTRIMP), Edwards TRIMP, Lucia TRIMP, individualized TRIMP (iTRIMP), and session RPE (sRPE). External-TL measures calculated were total distance, PlayerLoad™, high-speed distance > 15 km/h, very-high-speed distance > 18 km/h, and individualized high-speed distance based on each player’s vOBLA. Results: A second-order-regression (quadratic) analysis found that bTRIMP (R 2 = .78, P = .005) explained 78% of the variance and iTRIMP (R 2 = .55, P = .063) explained 55% of the variance in changes in VO 2 max. All other HR-based internal-TL measures and sRPE explained less than 40% of variance with fitness changes. External TL explained less than 42% of variance with fitness changes. Conclusions: In rugby players, bTRIMP and iTRIMP display a curvilinear dose-response relationship with changes in maximal aerobic fitness

Can we trust “Magnitude-based inference”?

Editoria

Characterising the application of the “progressive overload” principle of exercise training within cardiac rehabilitation: A United Kingdom-based community programme

Background: Recent concerns have cast doubt over the effectiveness of cardiac rehabilitation [CR] programmes for improving cardiorespiratory fitness [CRF] in patients with a history of cardiac disease in the United Kingdom [UK]. We aimed to characterise the weekly progression of exercise training dose over an 8-week Phase III CR programme as we felt this may be partly responsible for the lack of improvement in CRF reported in previous studies. Design: Observational study. Methods: We evaluated a community-based Phase III CR programme in the UK. During each training session, patients wore an Apple Watch and the weekly progression of exercise training dose/load was quantified. The analysis was based on 332 individual training sessions. Exercise intensity [% heart rate reserve] during the cardiovascular [CV] exercise training component [%HRR-CV], CV training duration; estimated changes in cardiorespiratory fitness [change in estimated metabolic equivalents (METs)]; session rating of perceived exertion [sRPE], sRPE training load [sRPE-TL], and exercise training impulse [TRIMP] were evaluated. Results: Thirty cardiac patients [83% male; age [SD] 67.0 [10.0] years; body mass index [SD] 28.3 [4.6] kg∙m-2] were recruited to an 8-week programme [16 sessions in total]. Bayesian repeated-measures ANOVA indicated anecdotal evidence for the alternative hypothesis for changes in %HRR-CV (BF10 = 0.61), sRPE (BF10 = 1.1), and change in estimated METs (BF10 = 1.2) during CR. Conversely, Bayesian repeated-measures ANOVA showed extreme evidence for changes in CV training duration (BF10 = 2.438e+26), TRIMP (BF10 = 71436), and sRPE-TL (BF10 = 779570). Conclusion: The key exercise training principle of progressive overload was only partially applied. Increases observed in exercise dose were due to increases in the duration of CV training, rather than combined with increases in exercise intensity [%HRR-CV and sRPE]. Accordingly, allied health professionals must ensure that exercise intensity is more consistently progressed to optimise the exercise stimulus and improvements in CRF and patient outcomes

The effects of the iPlayClean Education Programme on doping attitudes and susceptibility to use banned substances among high-level adolescent athletes from the UK: A cluster-randomised control trial

Background: This study examined the effects of the iPlayClean anti-doping intervention on attitudes towards doping and susceptibility, and whether delivery mode affected the results. Methods: A total of 1,081 high-level UK athletes (14-18 years old, 904 males, 177 females) were cluster-randomised to the control (11 teams/organisations/schools, 314 athletes), face-to-face group presentation (8 teams/organisations/schools, 254 athletes), online (11 teams/organisations/schools, 251 athletes), or face-to-face presentation with online access (5 teams/organisations/schools, 262 athletes). Results: Compared to the control group, all modes of the iPlayClean anti-doping education programme reduced favourable attitudes towards doping immediately after the intervention, which was sustained across all intervention groups 8 weeks later. All delivery modes impacted doping susceptibility immediately after the intervention, in comparison to the control group, but the effects were only sustained for the face-to-face presentation group. Conclusion: Contrary to findings within previous anti-doping interventions, we have shown that doping attitudes can be changed and that the results can be sustained across all modes of delivery, 8 weeks later. Research is required to assess for how long these changes are sustained, and how often anti-doping education should be delivered to high-level athletes to reinforce clean play values

Limits on the production of scalar leptoquarks from Z (0) decays at LEP

A search has been made for pairs and for single production of scalar leptoquarks of the first and second generations using a data sample of 392000 Z0 decays from the DELPHI detector at LEP 1. No signal was found and limits on the leptoquark mass, production cross section and branching ratio were set. A mass limit at 95% confidence level of 45.5 GeV/c2 was obtained for leptoquark pair production. The search for the production of a single leptoquark probed the mass region above this limit and its results exclude first and second generation leptoquarks D0 with masses below 65 GeV/c2 and 73 GeV/c2 respectively, at 95% confidence level, assuming that the D0lq Yukawa coupling alpha(lambda) is equal to the electromagnetic one. An upper limit is also given on the coupling alpha(lambda) as a function of the leptoquark mass m(D0)

An attempt to assess the effect of oral creatine monohydrate supplementation on prolonged high-intensity intermittent exercise that simulates team sport play

Two studies were conducted to examine the effect of oral creatine monohydrate supplementation on prolonged high-intensity intermittent exercise that simulated team sport play. Study 1 aimed at developing and validating a team sport play simulation. An activity profile representative of team sport play was developed. The activity profile was based on a number of time and motion studies of various sports including soccer, rugby union, basketball and Australian rules football. The activity profile was based around a 15 min protocol comprised of standing still, walking, jogging, running, fast running and sprinting. Each movement category speed was based on a percentage of the participant's peak sprinting speed. There were 94 changes in speed with a mean change in speed every 9.6 s during the 15 min activity profile. These changes in speed included three 3 s sprints and three 6 s sprints throughout the 15 min activity profile. The 15 min activity profile was repeated three times (45 min), followed by a 15 min break, followed by another three 15 min periods (45 min) for a total work duration of 90 min. The team sport play simulation was conducted on a non-motorised treadmill to allow participants to sprint more effectively than on a motorized treadmill and also allow changes in sprint speed to be measured. A Woodway non-motorised treadmill was instrumented to allow the measurement of force, power, speed and distance. Measures of oxygen uptake, heart rate, blood lactate and RPE were also collected. Five participants covered a mean distance of 10196 ± 403 m over the 90 min protocol, which is within the values typically observed during team sport play (Reilly, 1994). Heart rate and oxygen uptake throughout the protocol averaged 170 b·min⁻¹and 74% Vo₂max respectively, which compare favourably to actual match-play (Bangsbo, 1994). Blood lactate concentration averaged 8.7 mmol·L⁻¹over the course of the simulation, which is somewhat higher than previously reported during actual match play (Reilly and Doran, 2001). Peak sprint speed declined significantly from 24.9 ± 0.9 km·h⁻¹in the first half to 23.6 ± 0.7 km·h⁻¹in the second half. While no previous studies have reported the changes in peak sprint speed during team sport play, Bangsbo (1994) reported that mean 20 m sprint speed declined by 2.3% in soccer players following a match. The team sport play simulation was found to have acceptable reliability (coefficient of variation) for the total distance covered (2.2%) and peak sprint speed (4.1% and 3.5% for the 3 s and 6 s sprints, respectively). However, peak sprint power was found to be an unreliable measure with a coefficient of variation of 8.8% for the 3 s sprints and 10.2% for the 6 s sprints. The results of Study 1 strongly suggest that the treadmill protocol effectively recreated the movement patterns and physiological responses to team sport play and therefore demonstrated both logical and criterion validity. Study 2 extended the validated treadmill protocol to the examination of the effect of oral creatine monohydrate supplementation for team sport play. Twelve participants completed the protocol following either five days of oral creatine monohydrate supplementation or placebo supplementation. Participants allocated to the creatine group were required to supplement their normal diet with creatine monohydrate (Creatine Plus, Sport-Test, Australia) at a rate of 20 g·day⁻¹. Participants were required to consume 5 g of creatine monohydrate plus 1 g of glucose four times per day. Muscle biopsies were performed prior to and following each simulation. Muscle samples were analysed for glycogen, phosphocreatine, ATP, free creatine, total adenine nucleotides and lactate. There were no significant differences between the creatine and placebo groups for the performance measures of total distance covered, mean peak sprint speed or sprint distance. There were also no significant differences between the groups for any of the physiological measures including heart rate, oxygen uptake, plasma lactate, RPE, body mass and plasma uric acid. While the results suggest that creatine-loading does not enhance team sport play performance, there was no significant difference in total muscle creatine concentration between the treatment and placebo groups prior to the team sport play simulation. There were a number of limitations in the design of the present study, such as the lack of a presupplementation muscle biopsy and a small sample size that have reduced the value of the present study. Consequently, no conclusions regarding the efficacy of creatine supplementation for team sport players can be drawn from the current study. Further detailed experiments are required before the practice of oral creatine monohydrate supplementation can be recommended for team sport players

Oxygen uptake during modern dance class, rehearsal, and performance.

The aim of the present study was to examine whether the workload, expressed in oxygen uptake and heart rate, during dance class and rehearsal prepared the dancer for performance. Previous research on the demands of class and performance has been affected by equipment limitations and could only provide limited insight into the physiological demands placed on the dancer. The present study noted that dance performance had significantly greater mean oxygen uptake and heart rate than noted in both class and rehearsal (p < 0.05). Further analysis noted that, during class and rehearsal, heart rates were rarely within the aerobic training zone (60-90%HRmax, where HRmax is the maximum heart rate). Dance performance placed a greater demand on the aerobic and anaerobic glycolytic energy systems than seen during class and rehearsal, which placed a greater emphasis on the adenosine triphosphate-creatine phosphate system. Practical implications suggest the need to supplement training within dance companies to overcome this deficit in training demand