Training Impulse Research Articles

Physical, physiological demands and movement profiles of professional men’s field hockey games

The aim of this study was to investigate the physical demands, physiological demands, and movement profiles of different positions across four quarters in professional men’s field hockey games. Eighteen professional male field hockey players participated in the study, and data were collected in eleven official matches. Players wore global positioning system units and heart rate monitors to collect physical, physiological, and movement profile data. Defenders had significantly higher absolute total distance covered, player load, acceleration and deceleration count, and forward-backward initial movement analysis (IMA) count, but lower high speed running distance, compared with midfielders and forwards (p<.05). However, when using relative metrics (normalised by playing time), defenders had the lowest physical and physiological outputs, and forwards were the highest (p<.05). Total distance covered per minute, high-speed running distance per minute, player load per minute, acceleration and deceleration count per minute, and repeated high-intensity efforts per minute were all significantly higher in quarter 1 than in other three quarters (p<.05). The percentages of linear running and non-linear dynamic movement duration decreased quarter by quarter. Modified training impulse per minute reached its peak in quarter 2 (p<.05). It was concluded that defenders had the highest volume in terms of the game demands due to their high playing minutes; however, they had the lowest relative volume compared with other two positions. Forwards had the highest linear running intensity, while midfielders were required to perform more multi-directional, non-linear movements. Quarter 1 was the most active quarter and players became fatigued in quarter 2. IMA counts were not sensitive to fatigue compared to movement profile and modified training impulse variables.

Comparison of cognitive strategies for emotion regulation, impulsivity and suicidal ideation in people with obsessive-compulsive disorder, bipolar people disorder and normal people

Aim: The aim was to compare cognitive strategies for emotion regulation, impulsivity, and suicidal ideation in patients with obsessive-compulsive, bipolar disorder and normal individuals.
 Methods: This was a causal-comparative study. The statistical population included people who were diagnosed with obsessive-compulsive disorder and bipolar disorder in city of Semnan, Iran in the year 1400. According to the opinion of a psychiatrist, as well as normal people who were not diagnosed with a disorder based on self-report and using a checklist of symptoms of mental disorders. Fifty obsessive-compulsive patients and 50 bipolar patients, as well as 50 normal individuals were selected through available sampling. Granfsky Emotion Cognitive Regulation Questionnaire, Barthes Impulsivity, and Beck Suicidal Thought were administered. Multivariate analysis of variance was used to analyze the data.
 Findings: Cognitive regulation of emotion, impulsivity and suicidal ideation are significantly different in the three groups. The mean scores of the patient group were higher than the normal group in the negative components of emotion regulation, impulsivity and suicidal ideation (p<0.05). In the positive of emotion regulation, the mean scores of the bipolar group were higher than the obsession (p<0.05). In negative regulating emotion, the mean scores of obsessive-compulsive patients were higher than those of bipolar disorder (p<0.05). Also, the mean scores of obsessive-compulsive group was higher than bipolar in cognitive impulsivity (p<0.05 ); but there was no difference between the obsessive-compulsive and bipolar groups in motor components and lack of planning (p>0.05).
 Conclusion: Holding educational workshops to minimize the damage caused by failure in emotion regulation, impulsivity, and suicidal thoughts in obsessive-compulsive and bipolar disorder sufferers, designing support programs such as training impulse management skills, using adaptive emotion regulation strategies, planning skills and decision-making in the general population as well as obsessive-compulsive and bipolar patients, as well as the appropriate treatment plan to prevent the exacerbation or recurrence of patients' symptoms can be effective.

Effectiveness, implementation, and monitoring variables of intermittent hypoxic bicycle training in patients recovered from COVID-19: The AEROBICOVID study.

Hypoxic exposure is safely associated with exercise for many pathological conditions, providing additional effects on health outcomes. COVID-19 is a new disease, so the physiological repercussions caused by exercise in affected patients and the safety of exposure to hypoxia in these conditions are still unknown. Due to the effects of the disease on the respiratory system and following the sequence of AEROBICOVID research work, this study aimed to evaluate the effectiveness, tolerance and acute safety of 24 bicycle training sessions performed under intermittent hypoxic conditions through analysis of peripheral oxyhemoglobin saturation (SpO2), heart rate (HR), rate of perceived exertion (RPE), blood lactate concentration ([La-]) and symptoms of acute mountain sickness in patients recovered from COVID-19. Participants were allocated to three training groups: the normoxia group (GN) remained in normoxia (inspired fraction of O2 (FiO2) of ∼20.9%, a city with 526m altitude) for the entire session; the recovery hypoxia group (GHR) was exposed to hypoxia (FiO2 ∼13.5%, corresponding to 3,000m altitude) all the time except during the effort; the hypoxia group (GH) trained in hypoxia (FiO2 ∼13.5%) throughout the session. The altitude simulation effectively reduced SpO2 mean with significant differences between groups GN, GHR, and GH, being 96.9(1.6), 95.1(3.1), and 87.7(6.5), respectively. Additionally, the proposed exercise and hypoxic stimulus was well-tolerated, since 93% of participants showed no or moderate acute mountain sickness symptoms; maintained nearly 80% of sets at target heart rate; and most frequently reporting session intensity as an RPE of "3" (moderate). The internal load calculation, analyzed through training impulse (TRIMP), calculated using HR [TRIMPHR = HR * training volume (min)] and RPE [TRIMPRPE = RPE * training volume (min)], showed no significant difference between groups. The current strategy effectively promoted the altitude simulation and monitoring variables, being well-tolerated and safely acute exposure, as the low Lake Louise scores and the stable HR, SpO2, and RPE values showed during the sessions.

Designing a small-sided game to elicit attacking tactical behaviour in professional rugby union forwards

ABSTRACT This study aimed to investigate the consistency of attacking tactical and technical behaviour, and physical characteristics, over multiple bouts, and variability across days, of a specific rugby union forwards small-sided game (SSG). Data was collected from 21 professional rugby union forwards during four training sessions. The SSG, consisting of five bouts of work (150-s) interspersed by passive recovery (75-s), aimed to elicit specific attacking tactical behaviour. Tactical behaviour (i.e., regularity of attacking shape [entropy]), and technical (e.g., passes) and physical (e.g., total distance) characteristics were quantified. Results showed that technical characteristics remained consistent, whereas the regularity of width of the attacking shape and two physical characteristics (i.e., total distance, training impulse) varied across bouts. However, these effects had limited practical significance. Technical characteristics were consistent across days, but minimal variability was observed for tactical behaviour and physical characteristics, as shown by their small random effects with 95% profile likelihood confidence intervals (PLCI) including zero (e.g., SD[95%PLCI] = 0.03[0.00, 0.06]). Consequently, consistency of stimulus over bouts and days is achievable for the majority of the variables investigated, thus supporting the use of SSG to elicit consistent attacking behaviour, but also technical and physical characteristics in rugby union forwards.

Physiological Demands and Muscle Activity of Jockeys in Trial and Race Riding.

Physiological parameters and muscle activity of jockeys may affect their fall and injury risk, performance, and career longevity, as well as the performance and welfare of the horses they ride. Therefore, this study aimed to quantify the physiological demands, body displacement, and electromyographic (EMG) activity of twelve jockeys riding 52 trials and 16 professional races. The jockeys were instrumented with heart rate (HR) monitors, accelerometers, and integrated EMG clothing (recording eight muscle groups: quadriceps, hamstrings, gluteal, erector spinae/lower back, abdominal external obliques, abdominal, trapezial and pectoral) which recorded continuously whilst riding. During race day, jockeys rode an average of 5 ± 4 trials and 4 ± 2 races over 2−2.5 h. The trials represented lower intensity cardiovascular demand (~81% HRmax) and Training Impulse (TRIMP) scores (4.4 ± 1.8) than races at maximal intensity effort (~94% HRmax, 7.2 ± 1.8 TRIMP, p < 0.05). Jockey head displacement was similar in trials (5.4 ± 2.1 cm) and races (5.6 ± 2.2 cm, p > 0.05), with more vertical (6.7 ± 2.7 cm) and less medio/lateral (2.3 ± 0.7 cm) and fore/aft (3.7 ± 1.6 cm) displacement for jockeys riding in trials than races (5.5 ± 2.3, 2.8 ± 1.0, 5.6 ± 2.5 cm, p < 0.05). Jockeys in races adopted a lower crouched posture, with their centre of mass (COM) shifted anteriorly, using greater hamstring activation and less upper arm muscle activation than in trials. The differences in riding posture and physiological demands on jockeys riding in a race rather than a trial, highlight the requirement for an off-horse race-specific training programme to improve jockey fitness and performance. Greater jockey stability and coordination will have mutual benefits for both horse welfare and performance.

Utilizing Countermovement Jumps As A Measure Of Match Preparedness In NCAA Division I Women’s Soccer

PURPOSE: Training load quantification and monitoring is used in collegiate athletics to help coaches and supporting staff to determine whether players are prepared for upcoming matches. The purpose of this study was to assess the within-subjects correlation of matchday countermovement jump (CMJ) height and the 7-day sum of training load variables preceding matchday in NCAA Division I women’s soccer athletes. The authors hypothesized that matchday CMJ height would show negative moderate correlations with the 7-day sum of training load variables. METHODS: A total of 23 female soccer players (20 ± 1.1 years; 1.70 ± 0.07 m; 64.6 ± 7.0 kg) participated in this study. Data from seven matches from the 2020 season were included in this analysis. Repeated measures correlations (rmcorr) were used to determine the within-subjects correlations of matchday CMJ height and total distance covered (TD), training load score (TLS; using training impulse [TRIMP] calculations), number of sprints, and distanced covered at high-speed (< 9.32 mph; HODO). Alpha was set a priori at p ≤ 0.05 and the data was analyzed using R Studio (version 1.4.1106, R Studio, Boston, MA, USA) executing R (version 4.0.4, University of California, Berkeley, CA, USA). RESULTS: The correlations between training load variables and matchday CMJ height were not statistically significant (p > 0.05). The matchday CMJ height showed very weak nonsignificant relationships with TD (r = -0.071, p = 0.450, 95% CI = -0.254, 0.116), TLS (r = -0.016, p = 0.874, 95% CI = -0.191, 0.223), number of sprints (r = -0.116, p = 0.218, 95% CI = -0.296, 0.071), and HODO (r = -0.011, p = 0.904, 95% CI = -0.175, 0.197). CONCLUSIONS: The results suggest that the CMJ height may not be a good indicator of matchday preparedness in collegiate Division I women’s soccer as it did not correlate with the 7-day sum of training load variables preceding matchday. Future research should aim to address other strategies to assess matchday preparedness in collegiate women’s soccer in order to enhance training periodization to better prepare the athletes for competition.

Inter-limb Asymmetries, Power, And Internal Training Loads In NCAA Division I Female Soccer Athletes

Periodic testing and workload monitoring throughout a competitive season can help athletes and coaches periodize training to optimize performance. In particular, vertical jump testing to assess power output and inter-limb asymmetries can be used to monitor athlete-readiness. PURPOSE: To evaluate the relationship between internal training loads, power output, and inter-limb asymmetries throughout a competitive soccer season. METHODS: National Collegiate Athletic Association (NCAA) Division I female soccer players (N = 21) were evaluated at all practices and games using a team-based heart rate monitoring system to assess internal training load via Banister’s training impulse score (TRIMP). At the beginning of each week, athletes performed a dynamic warmup followed by maximal bilateral (CMJ) and single leg (SL) countermovement vertical jump tests using a hands-on-hips method assessed via a digital contact mat. The best of two trials were used for each jump test. An asymmetry index (ASY) was calculated by dividing dominant by non-dominant SL height. Linear mixed effects models were used to assess changes in TRIMP, CMJ, and ASY throughout the season. Repeated measures correlations were used to determine relationships between weekly changes in TRIMP, CMJ and ASY using an absolute ASY score. Significance was set at p < 0.05. Descriptive statistics are presented as mean ± standard deviation. RESULTS: Time main effects were observed for weekly changes in TRIMP (573 ± 150au; p < 0.001) and CMJ (43.1 ± 0.8 cm; p = 0.01) over the season. No changes in ASY were observed (2.0 ± 1.5%; p = 0.09). There was a significant weak correlation between CMJ and ASY (r = 0.17; p = 0.04), but no other relationships between TRIMP, CMJ, and ASY were observed (p > 0.05). CONCLUSIONS: Changes in internal workload and power output were apparent throughout the season. Although no significant changes in ASY were seen, an inverse correlation between ASY and power output was observed, which may impact on-field performance. Declines in peak power along with higher asymmetry rates have been associated with increased injury risk. Proper athlete management programs that incorporate systematic monitoring and periodic testing may help to mitigate these risks by affording the opportunity for early interventions designed to improve athlete readiness.

Self-Paced Cycling at the Highest Sustainable Intensity With Blood Flow Restriction Reduces External but Not Internal Training Loads.

This study compared training loads and internal:external load ratios from an aerobic interval session at the highest perceptually sustainable intensity with and without blood flow restriction (BFR). On separate days, 14 endurance cyclists/triathletes completed four 4-minute self-paced aerobic cycling intervals at their highest sustainable intensity, with and without BFR (60% of arterial occlusion pressure). Internal training load was quantified using 3 training impulses (TRIMP; Banister, Lucia, and Edwards) and sessional ratings of perceived exertion. External load was assessed using total work done (TWD). Training load ratios between all internal loads were calculated relative to TWD. Lucia TRIMP was lower for the BFR compared with non-BFR session (49 [9] vs 53 [8]arbitrary units [au], P = .020, dz = -0.71). No between-conditions differences were observed for Banister TRIMP (P = .068), Edwards TRIMP (P = .072), and training load in sessional ratings of perceived exertion (P = .134). The TWD was lower for the BFR compared with non-BFR session (223 [52] vs 271 [58]kJ, P < .001, dz = -1.27). Ratios were greater for the BFR session compared with non-BFR for Lucia TRIMP:TWD (0.229 [0.056] vs 0.206 [0.056]au, P < .001, dz = 1.21), Edwards TRIMP:TWD (0.396 [0.105] vs 0.370 [0.088]au, P = .031, dz = 0.66), and training load in sessional ratings of perceived exertion:TWD (1.000 [0.266] vs 0.890 [0.275]au, P = .044, dz = 0.60), but not Banister TRIMP:TWD (P = .306). Practitioners should consider both internal and external loads when monitoring BFR exercise to ensure the demands are appropriately captured. These BFR-induced changes were reflected by the Lucia TRIMP:TWD and Edwards TRIMP:TWD ratio, which could be used to monitor aerobic BFR training loads. The Lucia TRIMP:TWD ratio likely represents BFR-induced changes more appropriately compared with ratios involving either Edwards or Banister TRIMP.

Dose-response relationship between training load and anaerobic performance in female short-track speed skaters: A prospective cohort study

This study aimed to assess the dose-response relationship (DRR) between measures of training load (TL) and anaerobic performance in female short-track speed skaters. TL data from 22 female short-track speed skaters (mean ± SD; calendar age 20.7 ± 2.01 years, training length 4.18 ± 1.23 years, height 164.20 ± 5.53 cm, weight 52.00 ± 5.58 kg) was collected over a six week period. Participants completed two anaerobic capacity assessments (cycling parameters: total work, maximal anaerobic power [MAnP], power duration indices, maximal blood lactate, fatigue indices, and peak power output [PPO]) pre- and post-training, which included three tests (short-term, intermediate-term, and 120 s maximal anaerobic test). The mean weekly TL measures calculated were total distance, red zone (time spent > 85% of peak heart rate), Edwards training impulse (eTRIMP), Stagno training impulse (gTRIMP), Lucia training impulse, and session ratings of perceived exertion. The gTRIMP identified a curvilinear relationship and explained 79% and 63% of the variance in changes of MAnPi and PPO (R2 = 0.79, 95%CI = 0.64 to 1.00, turn point 621AU; R2 = 0.63, 95%CI = 0.27 to 1.00, turn point 633AU, respectively). Likewise, The eTRIMP identified a curvilinear relationship and explained 62% and 54% of the variance in changes of MAnPi and PPO (R2 = 0.62, 95%CI = 0.11 to 1.00, turn point 485AU; R2 = 0.54, 95%CI = 0.07 to 1.00, turn point 515AU, respectively). All other variables exhibited a DRR below moderate. This study investigated a TL strategy to improve the speed endurance of female short-track speed skaters and suggested the superiority of gTRIMP and eTRIMP methods of internal TL.

Effect of Strength vs. Plyometric Training upon Change of Direction Performance in Young Female Handball Players.

The aim of the current study was to investigate the effect of six weeks of strength vs. plyometric training upon change of direction (COD) performance. A total of 21 young female handball players were randomly assigned to either a strength group: (n = 11, age: 17.5 ± 2.3 years, height: 1.69 ± 0.05 m, weight: 65.8 ± 5.9 kg) training bilateral, unilateral and later squats; or a plyometric training group (n = 10, age: 17.1 ± 2.4 years, height: 1.73 ± 0.07 m, weight: 67.1 ± 9.3 kg) training drop jumps, unilateral countermovement jumps and skate-jumps. Groups were assigned after being pair-matched based upon baseline COD performance. The training modalities were matched in training impulse. A force- (180°) and velocity-oriented (45°) COD of 20 m was used to measure changes in COD performance (10 m + COD + 10 m). Total time (s) to complete the COD test was defined as the performance variable. The level of significance was set at p < 0.05. The two-way ANOVA showed no group effect upon COD performance. A significant effect was only observed for the strength training group in the last 10 m and total 20 m of the force-oriented COD (F ≥ 5.51; p ≤ 0.04; η2 ≥ 0.36). Both groups improved performance in other strength- and power-related tests. It was concluded that only the strength training program was effective in developing force-oriented COD performance in the studied population, while the plyometric training program was not sufficient. Both training modalities are useful for improving performance in different strength and power tests in young female handball players.

The association between training load and physical development in professional male youth soccer players: a systematic review

Objectives 1) To evaluate current physical performance tests used within professional male youth soccer; 2) to understand the relationship of these tests performance in relation to specific measures of external and internal training load (TL) to conclude if there is a subsequent change in test performance. Methods Relevant literature was searched using five electronic databases (PubMed Medline, SPORTDiscus, Web of Science, CINAHL and Scopus), with additional articles identified by the authors. Articles relating to TL and physical development assessment within professional male youth soccer players were evaluated. Results Database searches yielded 5683 articles following removal of duplicates. After screening the titles, abstracts and full texts, 28 articles were identified. Both external TL (total distance, high speed distance, duration) and internal TL (rating of perceived exertion, training impulse) measures were found to be associated with improvements in physical test performance across both pre-season and in-season phases. Field-based testing was found to be sensitive to changes in physical performance for aerobic capacity, lower body power/strength and sprint performance. However, limited sensitivity to change was found when assessing player agility performance. Conclusion Future research in this area should look to enhance our understanding of the dose-response of TL with changes in fitness across different age groups in professional male youth soccer.

A Validation Study of Heart Rate Variability Index in Monitoring Basketball Training Load.

This study aimed to investigate whether the heart rate variability index (TLHRV) during five ball-drills could be used to quantify training load (TL) in collegiate basketball players. Ten elite male college basketball athletes (18.2 ± 0.4 years) were recruited to perform five ball-drills (1V1, 2V2, 3V3, 4V4, and 5V5) which lasted 10 min and varied in intensity. During each drill, TLHRV, training impulse (TRIMP), rating of perceived exertion (RPE), speed, and distance were recorded by Firstbeat, Foster’s RPE scale, and SiMi Scout. The correlation (Spearman’s and Pearson’s correlation coefficient), reliability (intra-class correlation coefficient, ICC), and agreement (Bland-Altman plots) among TLHRV, TRIMP, RPE, speed, and distance were examined. TLHRV was significantly correlated with TRIMP (r = 0.34, p = 0.015) and RPE (r = 0.42, p = 0.002). TLHRV was significantly correlated with training intensity (r = 0.477, p = 0.006) but not with volume (r = 0.272, p = 0.056). TLHRV and TRIMP, RPE showed significant intraclass relationships (ICC = 0.592, p = 0.0003). Moreover, TLHRV differentiated basketball drills of equal volume and varying intensity. We concluded that TLHRVmay serve as an objective and rational measure to monitor TL in basketball players.

Quantifying Internal Load in Pre-Professional Contemporary Dancers: The Association Between Objective Heart-Rate Derived Outcome Measures and Subjective Dancers' and Teachers' Perceptions.

Monitoring heart rate is one of the most common methods used to quantify internal training load (ITL) in athletes. The aim of this study was to determine whether subjective measurements can be used as a simple, non-invasive, and inexpensive method for assessing ITL in pre-professional contemporary dancers. <br/>Method: A total of 16 first-year contemporary dance students participated in this study. Students wore heart rate monitors during 56 training sessions. After each session, students completed the rate of perceived exertion (RPE) scale and teachers completed the rate of observed exertion (ROE) scale. For each session, we calculated the session-RPEs (sRPE), session-ROEs (sROE), and heart-rate-derived ITLs [i. e., Banister TRaining IMPulse method (TRIMP) and Edwards TRIMP]. Pearson correlation coefficients were calculated to determine the association between sRPE, sROE, Banister TRIMP, and Edwards TRIMP. <br/>Results: Between-individual correlation between Banister TRIMP and subjective dancers' (sRPE) and teachers' perceptions (sROE) were moderate (r = .49, p < 0.01) to large (r = .57, p < 0.01). Between-individual correlations between Edwards TRIMP and the subjective perceptions (sRPE and sROE) were very large (r = .74, p < 0.01; and r = .79, p < 0.01). There was a statistically significant large (r = 0.52, p < 0.01) to almost perfect (r = 0.93, p < 0.01) within-individual correlation between the sRPE and the two measured TRIMP methods. There was a statistically significant small (r = .29, p < 0.01) to almost perfect (r = .92, p < 0.01) within-individual correlation between the sROE and the two measured TRIMP methods. <br/>Conclusion: The results of this study suggest that the sRPE is a simple, non-invasive, inexpensive, and valid method for quantifying ITL in pre-professional dancers.

A Fitness-Fatigue Model of Performance in Peripheral Artery Disease: Predicted and Measured Effects of a Pain-Free Exercise Program.

Banister impulse-response (IR) model estimates the performance in response to the training impulses (TRIMPs). In 100 patients with peripheral artery disease (PAD), we tested by an IR model the predictability of the effects of a 6-month structured home-based exercise program. The daily TRIMPs obtained from prescribed walking speed, relative intensity and time of exercise determined the fitness-fatigue components of performance. The estimated performance values, calculated from the baseline 6-min and pain-free walking distance (6MWD and PFWD, respectively) were compared with values measured at visits through regression models. Interval pain-free walking at controlled speed prescribed during circa-monthly hospital visits (5 ± 1) was safely performed at home with good adherence (92% of scheduled sessions, 144 ± 25 km walked in 50 ± 8 training hours). The mean TRIMP rose throughout the program from 276 to 601 a.u. The measured 6MWD and PFWD values increased (+33 m and +121 m, respectively) showing a good fit with those estimated by the IR model (6MWD: R2 0.81; PFWD: R2 0.68) and very good correspondence (correlation coefficients: 0.91 to 0.95), without sex differences. The decay of performance without training was estimated at 18 ± 3 weeks. In PAD, an IR model predicted the walking performance following a pain-free exercise program. IR models may contribute to design and verify personalized training programs.

Cross-Sectional Differences in Race Demands Between Junior, Under 23, and Professional Road Cyclists.

To compare the race demands of junior (JUN), under 23 (U23), and professional (PRO) road cyclists. Thirty male cyclists, divided into 3 age-related categories (JUN, n = 10; U23, n = 10; and PRO, n = 10), participated in this study. Race data collected during the 2019 competitive season were retrospectively analyzed for race characteristics, external, and internal competition load. Higher annual and per race duration, distance, elevation gain, Edward's training impulse, total work, and work per hour were observed in PRO versus U23 and JUN, and U23 versus JUN (P < .01). PRO and U23 recorded higher mean maximal power (RPOs) between 5 and 180minutes compared with JUN (P < .01). Edward's training impulse per hour was higher in JUN than PRO and U23 (P < .01). Accordingly, JUN spent a higher percentage of racing time in high internal intensity zones compared with U23 and PRO, while these 2 categories spent more time at low internal intensity zones (P < .01). JUN races were shorter and included less elevation gain per distance unit compared to U23 and PRO races, but more internally demanding. JUN produced less power output in the moderate-, heavy-, and severe-intensity exercise domains compared with U23 and PRO (RPOs: 5-180min). U23 and PRO races presented similar work demands per hour and RPOs, but PRO races were longer than U23.

Impulse Data Models for the Inverse Problem of Electrocardiography

To develop, train and test neural networks for predicting heart surface potentials (HSPs) from body surface potentials (BSPs). The method re-frames traditional inverse problems of electrocardiography into regression problems, constraining the solution space by decomposing signals with multidimensional Gaussian impulse basis functions. Impulse HSPs were generated with single Gaussian basis functions at discrete heart surface locations and projected to corresponding BSPs using a volume conductor torso model. Both BSP (inputs) and HSP (outputs) were mapped to regular 2D surface meshes and used to train a neural network. Predictive capabilities of the network were tested with unseen synthetic and experimental data. A dense full connected single hidden layer neural network was trained to map body surface impulses to heart surface Gaussian basis functions for reconstructing HSP. Synthetic pulses moving across the heart surface were predicted from the neural network with root mean squared error of 9.1±1.4%. Predicted signals were robust to noise up to 20 dB and errors due to displacement and rotation of the heart within the torso were bounded and predictable. A shift of the heart 40 mm toward the spine resulted in a 4% increase in signal feature localization error. The set of training impulse function data could be reduced, and prediction error remained bounded. Recorded HSPs from in-vitro pig hearts were reliably decomposed using space-time Gaussian basis functions. Activation times calculated from predicted HSPs for left-ventricular pacing had a mean absolute error of 10.4±11.4 ms. Other pacing scenarios were analyzed with similar success. Impulses from Gaussian basis functions are potentially an effective and robust way to train simple neural network data models for reconstructing HSPs from decomposed BSPs. The HSPs predicted by the neural network can be used to generate activation maps that non-invasively identify features of cardiac electrical dysfunction and can guide subsequent treatment options.

The Effect of Exercise Training Intensity on VO2max in Healthy Adults: An Overview of Systematic Reviews and Meta-Analyses.

This study aimed to evaluate systematic reviews and meta-analyses that have examined the effect of exercise training on VO2max in healthy individuals at different intensities. Five databases were searched: EBSCOhost, MEDLINE/PubMed, SPORTDiscus, Web of Science, and Google Scholar. Eligibility criteria for selecting reviews included systematic reviews and meta-analyses of healthy adults that examined the effect of lower intensity training (LIT) and/or high intensity training (HIT) on VO2max. Eleven reviews met the eligibility criteria. All reviews were of moderate-to-very strong methodological quality. The included reviews reported data from 179 primary studies with an average of 23 ± 10 studies per review. All reviews included in this overview showed that exercise training robustly increased VO2max at all intensities. Three meta-analyses that compared LIT versus HIT protocols on VO2max reported small/moderate beneficial effects for HIT over LIT; however, the beneficial effects of HIT on VO2max appear to be moderated by training variables other than intensity (e.g., training impulse, interval length, training volume, and duration) and participants' baseline characteristics (e.g., age and fitness levels). Overall, evidence from this overview suggests that the apparent differences between LIT and HIT protocols on VO2max were either small, trivial, or inconclusive, with several methodological considerations required to standardise research designs and draw definitive conclusions.

Internal Load of Male Varsity Ice Hockey Players During Training and Games Throughout an Entire Season.

The purpose of this study was to quantify the internal load of male varsity ice hockey players, using both sessional rating of perceived exertion (sRPE) and the heart rate-derived physiological measure of training impulse (TRIMP), during training sessions and competitions throughout an entire season. Twenty-seven male varsity ice hockey players (22.1 [1.1]y, 85.9 [5.4]kg, 181.3 [5.1]cm) were included in this longitudinal prospective cohort study. The internal load was significantly higher (P < .001) for games (sRPE: 403 [184]arbitrary units [AU], TRIMP: 98 [59]AU) compared with training sessions (sRPE: 281 [130]AU, TRIMP: 71 [35]AU). The regular season had the highest internal load compared with the preseason and postseason. There was evidence of microcycle periodization with training sessions several days prior to game days having the highest internal load (both sRPE and TRIMP) and tapering down as the subsequent training sessions approached game day. For positional comparisons, the goalies had higher sRPE (346 [151]AU, P < .001) and TRIMP (99 [64]AU, P < .001) compared with defense (sRPE: 295 [130]AU, TRIMP: 65 [29]AU) and forwards (sRPE: 264 [123]AU, TRIMP: 70 [30]AU) for training sessions, but no significant differences were present for competitions. Finally, there was an overall moderate and statistically significant relationship between the sRPE and TRIMP internal load measures (r = .434, P < .001). Internal load was greater during competitions versus training sessions in male varsity ice hockey players, and the microcycle assessment demonstrated that training sessions were tailored to game day. Mesocycle assessment revealed the highest internal loads during the regular season due to dense game scheduling and a short season.

Weekly Training Load in Elite Male Ice Hockey: Practice Versus Competition Demands.

The aim of this study was to compare training load (TL) between practice and games across in-season microcycles in elite Danish male ice hockey. Practice sessions and game data were collected using a wearable 200-Hz accelerometer, heart rate (HR) recording, and rating of perceived exertion (RPE) throughout 23 practice sessions and 8 competitive games (n = 427 files) and examined in relation to the number of days before the game (game day minus). Total accelerations, accelerations >2m·s-2 (Acc2), total decelerations, decelerations less than -2m·s-2 (Dec2), time >85% maximum heart rate (t85HRmax), Edwards TL, modified training impulse (TRIMPMOD), session-RPE, peak HR (HRpeak), and RPE were greater during competition than during practice (r = .19-.91; P < .05), whereas total accelerations per minute and total decelerations per minute were lower (r = .27-.36; P < .001). Acc2, t85HRmax, Edwards TL and TRIMPMOD, % t85HRmax, mean HR (HRmean), and RPE progressively decreased toward game day (r = .13-.63; P < .001). Positive correlations were found between Acc2, Dec2, Acc2 per minute, and Dec2 per minute during practice and during competition (r = .66-.84; P < .001). Evident within-week decreases in internal TL but not external TL were observed as the game day approached. Day-to-day variations were more pronounced in HR- and RPE-based parameters than accelerations and decelerations. Finally, the amount of intense accelerations and decelerations performed during practice was associated to the amount performed during competition, whereas physiological and perceptual demands showed no such relationship.

Effects of Increased Load of Low- Versus High-Intensity Endurance Training on Performance and Physiological Adaptations in Endurance Athletes.

To compare the effects of increased load of low- versus high-intensity endurance training on performance and physiological adaptations in well-trained endurance athletes. Following an 8-week preintervention period, 51 (36 men and 15 women) junior cross-country skiers and biathletes were randomly allocated into a low-intensity (LIG, n = 26) or high-intensity training group (HIG, n = 25) for an 8-week intervention period, load balanced using the overall training impulse score. Both groups performed an uphill running time trial and were assessed for laboratory performance and physiological profiling in treadmill running and roller-ski skating preintervention and postintervention. Preintervention to postintervention changes in running time trial did not differ between groups (P = .44), with significant improvements in HIG (-2.3% [3.2%], P = .01) but not in LIG (-1.5% [2.9%], P = .20). There were no differences between groups in peak speed changes when incremental running and roller-ski skating to exhaustion (P = .30 and P = .20, respectively), with both modes being significantly improved in HIG (2.2% [3.1%] and 2.5% [3.4%], both P < .01) and in roller-ski skating for LIG (1.5% [2.4%], P < .01). There was a between-group difference in running maximal oxygen uptake changes (P = .04), tending to improve in HIG (3.0% [6.4%], P = .09) but not in LIG (-0.7% [4.6%], P = .25). Changes in roller-ski skating peak oxygen uptake differed between groups (P = .02), with significant improvements in HIG (3.6% [5.4%], P = .01) but not in LIG (-0.1% [0.17%], P = .62). There was no significant difference in performance adaptations between increased load of low- versus high-intensity training in well-trained endurance athletes, although both methods improved performance. However, increased load of high-intensity training elicited better maximal oxygen uptake adaptations compared to increased load of low-intensity training.